Yesterday was round 3 of the BMW club's autocross season, down at Marina. This being California and almost midsummer, it was freezing out there. Actually it was high 50s, but damp and breezy, it certainly felt cold. The weather isn't unusual for the California coast. It makes summer events a much more palatable idea, than say Fresno which is having night events to avoid the heat (which was 96F yesterday).

There were two things I was experimenting with yesterday tire pressures and cameras. I think I'd just about worked out what the right front tire pressures are, so I was going to run 48psi (which I think is right) and then drop them down to 45psi for the last couple of runs.

I also had a new camera setup to address the short comings of the current setup. The current setup worked very well for driving on track, but wasn't quite right for autocross. I was using a handy cam on a mount in the boot. This gave a view of the driver and what's ahead on track. For autocross the view out the front wasn't ideal, it was difficult to see cones especially when they were close. Something with a wider view of the goings on just in front of the car would be better. The camera also didn't give me any idea how close I was getting to cones. That and the camera seemed to be going wrong and the focus wasn't focussing well anymore gave me the excuse to go get a new setup.

The new setup used 3 GoPro cameras. One was mounted in the middle of the car just behind the front seats at about eye level. This gave a good view of what was happening out front, and to the sides, and what the driver was doing. I fabricated a seatback mount for this myself (see below). The other two were mounted on the rear corners as "cone cams". They have a view along the side of the car and show how close the cones are. These were mounted with GoPro suction mounts. Just for fun, I also set the iPhone, which is running the lap timer on the dash to record video as well, so I have a "dash cam" view of the driver in action.



I also wanted to not to try to outthink myself. I've been a bit disappointed by the results of the last few events, I think I've been trying to be too clever with the lines I took. I thought I'd go back to a simpler line which would carry more speed. Again, they sent out the course map ahead of time, but I was a bit busy to analyse it in detail:



Cathy's out of town this week, so it was just me. After getting there early for the drivers meeting (amid dire threats that if you weren't there by 8:45am, you wouldn't be allowed on site), it was time to sit and do nothing for a while. As usual the entrants were split into three groups, one would run, the other work and the other had spare time. My group had spare time first. I thought about haging around and taking some photos, but it was too cold for that, so I sat in the car and listened to the commentary. The first group out was for cars which have 20-30 more points in the club classification system, that should give them a 2-3 second advantage over Tristan. The fastest times I heard were around 50 sec, so I was thinking about 53 seconds would be a good time.

I also took the opportunity to talk to Paul the driver of the other MINI in my class. At the last event he was about a half a second faster than me (ignoring cones), I was wanting to better his time. His MINI was an R50 with 17 (x7") wheels, plus a CAI, and a couple of braces up front. It got classed with 37 points vs Tristan's 34 points (worth a theoretical 0.3 sec).

There were several other MINIs around, but I didn't get to talk to most of their drivers. There was Eric in his STX MINI, we've seen him around in both SCCA and BMW club events (he usually PAXes quite high in SCCA). There was also another MINI I've never seen before, it was an R50, but it was classed with 45 points, so I was thinking it must have quite some mods to the suspension. I eventually bumped into one of the drivers of that, he's a BMW track instructor, and it was only his second autocross. I was pleased I ran faster than him, despite 11 extra points. It sounded like he had extensive suspension mods as well as more power.

After that and lunch it was time to run. I lined up on next to Paul. The first run was reasonable and I got a 52.7, which seemed like a very good start. In a few corners Tristan felt like he was lacking power, then I realised I'd left the DSC on and the traction control part was causing the problems. I turned off the DSC to be ready for the next run. Pauls first run was a 53.2, so I was even more pleased.

I went out for the second run thinking I could get a better time, but without the DSC Tristan turned into quite a handful. He started oversteering in several places around the course, I caught them, but lost time in the process. I ended up with a 53.4 0.7 seconds worse than my first run. So I tried again, and again. Tristan was still being difficult to control and after the first 4 runs, my best was still the first run. This was annoying for severl reasons, the first run is a practice run, and I didn't think it counted to the final time. Also I've been annoyed in the past when I couldn't match my earlier performance. Finding out that the better driver is your earlier self is annoying, what was even more annoying was finding out that my earlier self, with the help of a machine (DSC) was a better driver than I was. The only saving grace was that Paul still hadn't managed to better my first run either.

For the fifth run I put the plan into action and let the 3psi of air out of the tires. I was also running into battery problems, the GoPro batteries were draining much faster than I expected. I'd taken to switching off the cameras between runs to save battery, but still the left cone cam had run out of power and the internal camera was showing a low battery status (and quit during the fifth run). I went out and didn't notice much difference, my time was incrementally better than the last three, but still not up to the time I set for the first practice run.

I only had one more run, this time things went well. I'd noticed the interior camera had given up, so I quickly demounted the right cone cam and mounted it inside, so I'd have some record of what happened. There was still some oversteer, but I caught it and didn't lose much time, unfortunately I heard what sounded like a cone out near the back corner and another in the final slalom. The announcer only announced +1 cone, and the time was 51.8, over a second better than my previous run, so that would be my best run even with the cone, but it still wouldn't better my practice run. Of course the one run where it'd be really useful to have the cone cams, was the one when they weren't working.

The preliminary results are out now, thankfully they released them earlier than last week. http://home.comcast.net/~mgarage/Aut...RawResults.htm. I'm credited with 2 cones for that last run, so my fastest run is still the practice run. Though that run is shown as counting towards the final result. I see that Paul finally managed to pull out a fast run on his last run, and was 0.2 sec faster than my last run (and had no cones), so he was second in the class and I was third.

I extracted the results and put them in a spreadsheet, so I could workout the overall indexed results, which the BMW club don't usually do. They only use the points for classing, and in the "Gonzo" class (80+ points), they do index the cars. By that measure I'd be 20th overall out of 80 BMW/MINIs which count, if I hadn't had the two cones I'd have come 11th and edged out Paul by 1/100th of a second. I was 2.8 seconds behind the leader (indexed), and would have been 1.8 without the cones. I think my showing was pretty good.

I don't have any pictures as it was just me. I do have a multicam mosaic video of my first run. I haven't workout out how to use the multicam editor properly yet, so I made this simple video with the tools I already knew how to use.

http://btwyx.com/Movies/AxBMWJun13B1a.mov

And also one for my final run, which only has two cameras: http://btwyx.com/Movies/AxBMWJun13B6.mov

The cameras I'm going to have to work on. There's a few things I can do to help the batteries last longer. I'm also going to get a power supply so I can power a camera and/or recharge a battery while in the car. Next up I need to work out how to use the multicam editor (Final Cut Pro X) to see if I can do a better job of the editing.

As previously I was keeping an eye on the tire temperatures. One thing was immediatly obvious was they were a lot cooler than last weekend. This could have something to do with the ambient conditions, a lot cooler and no sun. It could also be to do with only having one driver, so they had a chance to cool off between runs. The tire temperature data would seem to suggest that 48psi is about right, they kept an even temperature throughout the day. When I let the 3psi out, they immediately heated up a lot (15-20 degrees) after the next run. This could be that 45psi is to low, so the tire flexes more causing heating. It also gives an interesting idea on how to control tire heating. I was thinking that the tires were a bit too warm last week, if I can put in a little more air and reduce the tire heating, while increasing the grip, this could be a good thing.

I think the oversteer I was experiencing was a consequence of getting the tire pressures right. The front tires now have the maximum grip possible, so they give up gripping later than the rear tires. Result: oversteer. I had been a little concerned about the absence of oversteer, I was thinking it might be a problem when we get better at this. The usual method of encouraging oversteer is to reduce the back end grip. I'm not fond of that idea as you're reducing overall grip. Now if the car is balanced towards oversteer with the front tires at optimal pressure, I can experient with the rear tire pressures. I think they're currently slightly too high (leading to a loss of potential rear grip), if I can optimise them I can then think about balancing the car as desired. I'm also in need of practice with Tristan in an oversteering mood, he's always been very stable before.

 

Sunday was round 6 of the SCCA's autocross season down in Marina. As California was sweltering under an extreme heatwave, Marina was quite pleasant. Mid 60s and sunny with a cold pacific breeze. (It was 40 degrees hotter inland on the way home.)

After the last event where Tristan was being a handful with lots of oversteer, I was trying to find the optimal rear tire pressures to balance out the handling. For the previous week, I was changing tire pressures and taking tire temperature while driving on the street. The results were very inconclusive. I ended up with a rear pressure of 45 psi, and was intending to let out 2psi for the last run.

We were in run group 2, work 3 so we didn't have to get there especially early. Walking the course it was obvious that it was going to be a fast course. The course ran out across the length of the concrete around a couple of cones, then swept all the way back with a straight. That was looking like we'd be having trouble hitting the limiter. Then the course went all the way back with a widely spaced (75 ft) slalom. With a slalom that wide we should be able to keep full throttle for most of the cones, possibly lifting for the last cone.

While waiting for our run group to arrive, I was listening to some of the times being set. One was announced as the 4th fastest time, I did a quick index calculation and worked out we're have to get to 43 sec to equal that. Also running in run group 1 was Steven in the ISF, the guy who'd won the novice class in the first round of the championship. He hadn't turned up since, but I was still wanting to beat his time. My calculation suggested I'd have to get 46 sec to beat him. (My calculation was wrong, I'd actually need 45 sec, and he'd miss classed his car so I really needed to beat 44s, but I only had the 46 sec figure in my head.) Also notably absent from our group was Chris in the Tangerine Scream (who was leading the novice championship). This was both good and bad news, it would probably allow me to retake the lead in the championship, but its unsatisfying to win by default.

It was Cathy's turn to go first, so she gave me a lift, she managed a 48.2. She seemed to have a little problem with oversteer, which was interesting as it might indicate my tire pressures weren't right. We'd also managed to leave the stability control on. The stability control should really have been controlling the oversteer. Then I gave Cathy a lift and got a 46.8, very nearly to my target of 46 sec. I was also suffering some oversteer.

Cathy went out for her second run, and I experimented with a new camera angle. We now had the handheld handycam that used to be mounted in the car and had been superseded by the GoPro cameras. I used the handycam to shoot Cathy's run from the outside. Cathy came in with a 46.6 and was gloating that her run was faster than mine. I did point out that my run was with a passenger (which I reckon is worth 0.6s). Talking of cameras I was running the GoPros again, one inside and one each for the left and right cone cams. After the batteries ran out prematurely at the last event I'd done some battery life tests and was running the cameras without Wi-Fi to extend the battery life. I'd also run a power cable to the internal camera so it was in no danger of running out.

For my second run I had less problems with oversteer, though it was still there and managed a 45.2. I was very pleased, almost a second faster than my target. As I expected, I was hitting the limiter at the end of the straight. It felt like I was on the limiter for several seconds but it was probably only 1-2. (I'm not sure as the data is missing at the crucial time.) That turned out to be my best run. The following runs I messed up the turn at the end of the straight. I was also hitting the limiter, a lot. For my last run I decided to try putting in an upshift to third. As I had a good time under my belt I wasn't really concerned about the time and thought I could experiment. It was a disaster, I didn't change down in time, and I was distracted and made a big big mess of the following corner, that was my slowest run.

Cathy showed her usual steady improvement, and ended up with a 46.3. I did let 2 psi out of the rear tires for the last two runs (we had 5 in total). Cathy's time did dip slightly after that. I'm not sure if that's showing the higher pressure is better, or if its just random.

The results are out: http://www.sfr-solo.org/solo2/Result...p/round06.html

In the absence of Chris and the Tangerine Scream I was first in Novice, and Cathy was second. In the championship I'm now back in first place, 30 points ahead of Chris. Cathy is still third. However the championship is calculated by dropping your worst result from 1 in 4 events. So by the end of the season another event's points will be dropped. Chris's results have dropped this zero point event and I've dropped my 3rd place. With the next drop, Chris may drop a 90 point event (5th place) and I'll drop a 160 second place. So after that Chris might be 10 points ahead at the moment. It all depends on if he turns up to future events.

Steven in the ISF wasn't running for points, but if he had been, his time was 1.7s better than mine. I've still got someways to go if I want to beat him.

Overall, I was 63rd (indexed) and Cathy was 81st out of 111. I was 5.9 and Cathy 7.9 "seconds behind" the leader. My result is as good as I managed at the March event.

As to the tire pressures, I'm still not sure what they should be, but I think I may be getting close.

All in all, it was a good day, and to cap it off we picked up our new MINI on the way home. The new one is destined to become our atuocross car when he's been broken in.

I have video, from the multiple angles I was taking. My best run (#2):

http://btwyx.com/Movies/AxJun13MaBBest.mov


And Cathy's best run (#5):

http://btwyx.com/Movies/AxJun13MaCBest.mov

 

Saturday was round 4 of the BMW club's season down at Marina. As the new MINI, who we're calling "Bertie", is not yet broken in, we took Tristan. However, as the autocross tires don't have many runs left in them, I wanted to run on different tires to save the regular ones for the SCCA events. I had planned to get some different wheels in 15"x6.5" size which aren't legal for SCCA this year, but will be next year, but they were back ordered so we didn't get them in time.

The BWM club's rules are different than SCCA's, instead of restricting what you can do to the car (which the SCCA does), they allow you to make any modifications you want, but then assign you more points for anything you do. The 15x6.5 wheels would not actually make any difference to the BMW club class points, they only take note of wheels width. The other alternative was to run Algy's track wheels. These are 17"x7", and are not legal for Tristan to run in SCCA, but would be legal for Bertie to run. (17" wheels were not an option MINI offered for a Cooper in 07, but they do offer them now, in fact we did get the 17" wheel option for Bertie.) For the BMW club, the 7" width just added 2 more class points.

Algy's wheels are shod in almost the exact same tire that we've been using, just 1" greater diameter. (They're Bridgestone RE-11 in 205/45-17 vs 205/45-16.) The tread depth remaining on both sets of tires is pretty similar as well, so this would make an interesting comparison. I used the same tire pressures in the 17" tires as I'd found worked for the 16" tires over the last few events.

As usual they published the course map ahead of time. My theory was the first few zigzags (past (1) and (2)) should be able to be taken flat out. The round bit around (3) would be interesting. The part from (3) - (4) would be taken flat out, so counts as a "straight" and would be the most important part of the course. I wasn't sure how the top of the course could be taken, whether its a straight, a slalom or just lots of little bits. The finish shouldn't cause any issues.



We got there early as usually, walked the course and then had our work assignments. We had one at each end of the course, I was starter and Cathy was the timeslips writer at the finish. Starter at BMW events is a little more complicated than SCCA, you radio in the car number so timing knows which car is up next. At SCCA a separate person runs the scanner to do that (and scans a barcode on your helmet). Things went very smoothly, and the cars ran with little incident, so they got in 7 runs each.

Then it was lunch time, and after lunch we had our down time. We were running in run group 3. Given the times I'd been hearing over the PA, I was thinking that 43 seconds would make a very good time. We also talked to a couple who were there for their first event. Catherine was driving a MINI Clubman-S in the same class (C) that we were, Tom her husband doesn't drive, but was there for support. We suggested if we were aiming for 43 sec, she should probably be happy if she could get to 50 seconds.

When it was finally our turn to run, Cathy went out first and gave me a lift. She got a 46.4, not unreasonable. I pointed out a few places where I thought she could gain a little time. Tristan was also being lively again, he was showing definite oversteer, particularly around the long turn around (3). Then I went for my first run, and got a 42.2. I was surprised to be so far ahead of our target, and quite so far ahead of Cathy's time.

For my second run, I had a little problem, I basically forgot about the little twiddle between (5) and (6), I came around the corner fast and found myself aiming right for the apex of the twiddle. Getting around the apex killed any momentum I had, and killed my time. For her next couple of runs, Cathy showed her usual steady improvement, getting a 43.0 on her third run. She was pleased that it was better than my second run time, even if it didn't better my first run time.

My third run knocked a second of my time (41.2), I was pleased. I could stand on that if necessary. I like to get a good time in the first three runs, as that's how many the SCCA guarantees you, so getting a good run early is important. (The SCCA's season is what I consider the main event of the season, the BMW club events are just for practice.) However, things didn't go quite so well for Cathy, her next run was almost 2 seconds slower (44.9), she was quite miffed. She usually shows a steady progression in her times, and she has no idea why she went backwards. We should probably study the video and see if we can work something out. Her 3rd run turned out to be her best of the day. She showed steady improvement over her 44.9 in her next three runs, but never managed to equal her third run time. In her last run she managed to spin the car trying to get around (3).

On the other hand, I had alternating good and bad runs. I messed up a couple of more times in the same way I messed up my second run. I looked up the course map on an iPhone to see if I could workout what I was doing wrong. After that I made an effort to take that corner on a wider line, so I could get around the twiddle in a more reasonable fashion. My time headed down, 40.9 on the 5th, and ending up with a 40.8. On my sixth run, I didn't do anything disastrous until the final corner, I over did it a bit and hit a cone on the exit. Trying to not hit the cone cost me time, as well as the penalty for the cone.

I did manage to keep my foot down for the first zigzags. The circle around (3) ws indeed interesting, where Tristan's oversteer showed itself most often, and indeed that's where Cathy had her spin. I was trying to keep my foot down around the "straight", it wasn't easy as you got going quite fast and the natural inclination is to lift for the corner. The lap timer is again showing gaps in its data, so I can't check that I did keep my foot down, I think I did at least for my last (and best) run. The last section was actually a series of short sections, with no theme linking them, and was what caused me most problems. The last corner didn't cause many problems, except when I overcooked it and collected the cone.

The results are not yet out, so we can't work out exactly how well we did. Overall I was very pleased with my showing, Cathy was miffed she couldn't do better than her third run, and get closer to my time. The last I heard Paul in the other MINI was stuck on 41.5, so I might have finally managed to better him. Steven in the Lexus ISF was there as well, one novice I've not managed to better this year. The last I heard from his time was pretty equivalent to mine (depending on what index you use).

Catherine in the Clubman started the day with a 50.something so was pleased. She got better during the day and ended up with a 46.something. She was very pleased with her showing, I think we'll see her back again.

I had a new toy for this event, an infrared thermal camera. Someone has made one for a semi reasonable price, it attaches to an iPhone over bluetooth and superimposes its 4x64 pixel thermal image over the iPhone's regular image. When it worked it does an admirable job of showing the tire temperatures, like this:



Which looks pretty even (which is good), maybe slightly over inflated. When it worked it was a quick way of gathering the data, my attempts to use the pyrometer at previous events were taking a long time. I'd hardly finished recording the results before it was time to run again. The problem was the iPhone ap didn't always work. It sometimes didn't connect to the camera, and sometimes decided it was just going to crash, and the only thing to do was reboot the iPhone. All in all, I didn't get as many measurements as I wanted to.

As I mentioned, Bertie, the new MINI, is not broken in yet, but we think he should be by next weekend. So next weekend, we're planning on taking both Bertie and Tristan to the SCCA event in Oakland. The idea is to run in the morning, swap tires and run again in afternoon. The morning run will be our regular championship run, the afternoon will be a "fun" run just for comparison. That will give us a good comparison of the MINIs. If nothing is horrendously wrong with Bertie, we're intending to run him as our regular autocross car from then on. Tristan will be for sale, if anyone wants a MINI, talk to us. We could both run one MINI in the morning, and the other in the afternoon, but with the wheels we have, we decided to make it a wheel comparison as well. Tristan will run the regular 16" wheels in the morning and the 17" in the afternoon. Bertie will run the 17" in the morning and the 16" in the afternoon. Neither of us knew which car would give us the best advantage in the championship, so we flipped a coin and Cathy will run Tristan in the morning.

I have video of course, my best run: http://btwyx.com/Movies/AxBMWJul13MaBest.mov

Cathy's best run: http://btwyx.com/Movies/AxBMWJul13MaCBest.mov

Cathy's spin: http://btwyx.com/Movies/AxBMWJul13MaCSpinxf.mov

and hitting the cone: http://btwyx.com/Movies/AxBMWJul13MaConea.mov

 

The results are out: http://xmdforum.com/brian/2013-AX4-P...nalResults.htm

First my calculation at the time was a bit wrong, it wasn't 43 seconds would have been a good time, 40.2 seconds would be a very good time, so we were gauging our runs against the wrong standard.

The results show Cathy's best run was credited with a cone, which is a surprise as she was no where near most of them. Looking at the video there is a downed cone at the exit of the final corner, it could be that she was credited with someone else's cone. That would be a bad break, her next best run is 1/3sec worse than that. I don't think anything could be done if that was the case. At the time, if she'd noticed, she could have stopped and pointed it out. That would have spoiled a good run, and she would have gotten a rerun. The downed cone looks just like one of the pointer cones in that row of cones, so you might not even notice it.

I came 4th in C class, and Cathy 8th (out of 12). Without the cone Cathy would have been 7th. I did beat Paul in the other MINI, he was half a second behind me. I didn't beat Steven in the Lexus (if you apply the SCCA's index, I was a bit over a second behind him.) Catherine in the Clubman came in 11th with a 45.1

I worked out the indexed results (using the BMW index, for some reason they don't publish these results). Out of 77 cars, I was 23rd and Cathy 62nd (would have been 50th without the cone). I was 3.5 "seconds behind" which is a substantially worse than at the last event (I was 2.8 sec behind, or 1.8 without my cone). Cathy was 6.9 seconds behind without the cone.

I'm not sure if the different wheels we were using was responsible for some of the difference, or this course was biased towards more powerful cars. Or if we were just having a slightly off day. Cathy thinks she was having a bit of an off day, I analysed the difference betweeen her best run and the following run where she was 1.9 sec slower. The main difference was the entry to two corners. At (3) and at (5) she took a slightly early apex, this messed up the next corner, which meant she was substantially slower entering the following "straight". That speed difference persisted along the straight which meant she lost about 1sec with each "straight".

If anyone wants to buy Tristan, he's up for sale now: http://btwyx.com/ForSale/

 

Thanks for the tale - I always enjoy reading your accounts. All the best.

Cheers,

Charlie

 

This one's long, so the tl;dr version: We tested Tristan against Bertie, Tristan seems to be faster, now we're confused. I came second, Its looking unlikely I'll win the championship.

Sunday was round 7 of the SCCA's season at the Oakland Coliseum. With the arrival of Bertie, I wanted to test one car against the other, this may have been a bit ambitious. The plan was to run in our regular morning run group, then swap the wheels (with their associated tires) and run in an afternoon run group for comparison. The swapping tires bit is important, as tires have the most impact on performance after the driver, so if we wanted to see what difference the car made, we needed to run on the same tires. As we didn't know which car would give us an advantage we decided to run both together, one of us in each car. We'd use our alternate set of wheels/tires on the second MINI, so this also might give us some comparison of the tires against each other. As the 17" wheels are not legal for Tristan, but are for Bertie, Bertie had the 17" wheels and Tristan had the 16" wheels. We tossed a coin to work out who had which car, and Cathy got Tristan for the morning.

To run twice, we also needed to work twice. We ended up being signed up for the gate waiver, both in the morning before run group 1, and in the afternoon for lunch (between run groups 3 and 4). These are usually difficult assignments to fill as the morning doesn't give you a chance to walk the course in the morning, and the afternoon doesn't give you a chance to walk the course for the afternoon sessions. We didn't need to walk the course for the afternoon, so that wasn't a problem. At a previous event Cathy had managed to get signed up for morning gate with the promise that someone would relieve her so she could walk the course and the relief never arrived. I ended up giving her a lift (as we usually do) as her "walk". This time We'd be able to relieve each other so we should be able to both walk the course, although that would cut down on the the time I had to walk the course. In the end I walked the course once, and then they announced the course closed for walking before Cathy got to the start. So again, I'd give her a lift on the first run as her "walk".

When I was walking the course, I bumped into Catherine from last week's event. We'd been in contact during the week, so I wasn't surprised to see her there. So we walked the course together and I gave her the benefit of my wisdom (whatever that's worth).

Given we had two cars running at the same time, I had to arrange for video and data for both cars. Tristan got the new 3 camera GoPro setup we'd used for the past couple events, and Bertie got the previous system with the handy cam in the boot. The old system doesn't give as good video as the new system, but at least its something. We'd been having trouble with the data, we have an Elm-Can WLan Wi-Fi dongle. This had been somewhat unreliable and gave periods where there was no data, usually at a crucial time you'd really want data. We use Harry's Lap Timer and Harry notes that it has reliability problems. So I checked what Harry recommends for a data dongle, he recommends a GoPoint unit, either a BT1 (BlueTooth) or a GL1 (hardwired iPod 30 pin connector). I wasn't sure which would work best, the hardwire solution sounds good, if you don't have to use wireless wired is usually more reliable and faster. The GL1 though would require a 30 pin to lightning connector to work with the iPhone. So I ordered both to try them out, we needed two data systems afterall. The GL1 I'd use with the iPod touch which usually lives in the MINI, it could connect to the BlueTooth GPS unit we use to make up for its lack of GPS. The other could use the BT1 and use the iPhones internal GPS. (We use the external GPS as its much more accurate, and is faster which prompts Harry's Lap Timer to log faster.) Tristan used the BT1 and iPhone, Bertie the GL1, GPS and iPod touch.

The morning run groups were large, so even with the first cars starting around 9am, it was 1:30pm before our run group started running. Our run group was particularly large as it had all the novice classes, there's usually a large turn out in Oakland. In the first group out Rob was running, now he no longer has a MINI, he had arranged to run co-drive with Brian in Brian's focus. Brian has been the fastest person in HS, a couple of seconds faster than me. I've been a bit faster than Rob so I was interested to hear one of his times announced. It was actually a 44.8, but by the time it mattered I'd forgotten, and was remembering 42.8. I wanted to find Rob to ask him how he did, to get an idea of times I should aim for, but he was working the course during run group two. 42.8 seemed unreasonable as that was being a good time for cars in faster classes. (Rob's best time was actually a 43.2, which would have been a good time to aim for, Brian got a 41.999, but I didn't know that at the time.)

While waiting to run, I also talked to Chris in the Tangerine Scream, my main rival. I'd worked out if I didn't beat him today, I'd have great difficulty winning the championship. (If he won, I'd have to win the next two rounds just to tie, assuming he came second each round. And if I didn't win here, it wouldn't be likely I'd be able to win those two rounds.)

I went out first, giving Cathy a lift so she could see the course. I obviously hadn't familiarized myself with the course too much as I promptly took a wrong turning. On my course walk I'd been a little worried that it was another fast course. There had been several like that at SCCA and even the BMW clubs last course had been quite fast. The problem with a fast course is the regular autocross tires assume a slower course, they're smaller diameter to give better acceleration, but that means they run out of revs in second sooner. We can be hitting the limiter on a fast course. I was running the 17" wheels, which give me a bit more headroom for top speed in second, at the expense of acceleration. Looking at the data I do have, neither of us had problems hitting the limiter, though it was getting very close (200 revs) on some runs.

After the first slalom, there's a left had right angle turn with a box around it. There are lots of cones pointing left, I instead of taking the hint to go left saw a couple of standing cones as a gate and headed for that going off course. I didn't bother trying to correct my error but rejoined the course later so I got a DNF for that run. It was a 47.??. Then we swapped cars and Cathy gave me a lift, she got a 47.0. The rest of the session was largely uneventful, though very long, it was almost 3pm by the time we finished. Unusually I decided we should turn off the engine between runs to save fuel, there was anything up to half an hour between runs, I usually just leave the engine running, but I wanted to make sure we still had fuel for the afternoon runs. I'd been very careful to make sure both cars had the same fuel load, to even out the comparison, and they did indeed seem to have the same amount of fuel on board. It was however slightly less than I might have wanted. I usually aim to have 20% fuel (as reported by Harry's Lap Timer), it started out as 15% and dropped to 13% while waiting for the first run (in both cars).

On the subject of evening out the comparison, I'd previously checked the acceleration of both MINIs with the 17" wheels, using "Dynolicious" on the iPhone. That suggested that the power to weight ratio of both MINIs is within 1% (maybe in Tristan's favor). Which is well within any experimental error, and works out to less than 3gal of fuel. I'd expect a 1% difference to make about 0.05sec difference over a 60 second run. (I reckon about 2ms per lb.)

My second run was 43.9 and Cathy's was 44.9. We both showed steady improvement over the next runs (4 in total), which is unusual for me, I'm usually a bit less consistant and most often have had my second run be my best. I ended up with a 43.7 and Cathy a 44.1.

Then it was "lunch" time (actually about 3pm) and we worked the gate for our second work assignment. When run group 4 started, there was no sign of relief for us, so I left Cathy on the gate and went to swap the wheels between the cars. I started to think this was being somewhat ambitious of me. Its now mid afternoon under the Californian sun. Luckily it wasn't too hot (only 65 degrees) or I might have expired. The afternoon run groups also seemed to be somewhat smaller than the morning, so I was worried about finishing in time. I reckon I can change a set of wheels in about 20 min, but swapping wheels from one car to another is a somewhat more involved operation than swapping loose wheels. It probably took me 40 min, but the run group took an hour or so, so we got to grid in plenty of time, and it was almost 5pm before our run group started. No one ever showed up to relieve us at the gate.

Our afternoon runs were uneventful, and went by quickly. I concentrated on trying to do the same as I did in the morning, to provide a good comparison. Tristan was more of a handful, I started suffering some oversteer, Cathy even noted the oversteer made Tristan more difficult to control. For one of my runs I got distinctly sideways exiting the first slalom, it was pretty wild, but it was faster. My first run was 42.9 and I improved to a 42.6. Cathy's first run was a 44.4 and she improved to a 42.7. It was almost 6pm by the time we finished, totally shattered and thinking the whole idea of comparisons may have been overly ambitions. We left after forgetting to help clean up, for which we've apologized. If they'd have made a PA announcement before our last runs we might have remembered we were supposed to help. On leaving I headed to the nearest gas station as the distance to empty was showing 23 miles, which was less than I was comfortable with.

On arriving home, the first thing I did was to look at the trends in our times. As I mentioned I was unusually consistant. Going by just the times I'd reckon that Tristan is about 0.66s faster than Bertie. I don't know if this is at all accurate, but if you compensate Bertie's times by 0.66s both of our times make very smooth lines on a graph. Without that fudge factor, they have definite steps in them at the changeover. Its possible that the difference is caused by other factors, like me having an ah-ha moment and knocking a second off my time getting into Tristan, while Cathy was more tired by the afternoon rolled around, but the data looks very compelling. So now we're wondering why. I've already eliminated power/weight as a factor.

This might prompt me to investigate Tristan's vs Bertie's suspension, to see if there is anything different. I'm wondering if one (or more) of Tristan's shocks is going bad, and it just so happens the way its gone bad is helping cause the oversteer. That would explain why we suddenly started having oversteer where we've never experienced it before. It just happened at a time where we could benefit from oversteer, and I was just putting the change down to playing with tire pressures. Though I was a bit surprised to still have oversteer at the end of my experiments with tire pressures. I'm wondering if I want to find a shop with a shock dyno (a somewhat specialized piece of kit) and measure Tristan's shocks to see if that's the secret sauce. I have a friend who has a shock dyno, but he's 3 hours away in Paso Robles. Before that I should just have a look at the shocks, the right ones are labeled "Sport", I haven't gone looking for the label on them.

I should also examine Bertie's springs, make sure he got the right ones at the factory. The springs are pretty anonymous, unlike the shocks and their "sport" label, but I might make an attempt to measure their spring rate and compare to Tristan. The springs are also a bit complicated, there are supposed to be various different springs, which depend on the exact weight of the MINI as manufactured with all its options. Supposedly the car's VIN can be checked to determine which ones are correct.

Another suggestion has also been made about the e-diff. We specifically ordered the DTC (Dynamic Traction Control) option as this seemed to be a good idea. When the DTC is turned off, and turned off again, its supposed to leave you with just the e-diff, as in electronic limited slip differential, called EDLC by MINI. A limited slip differential is a very good thing for autocross, it allows you to get more power down while exiting a corner. It controls slip by the lightly loaded inside wheel allowing more power to to go the heavily loaded outside wheel. A real physical limited slip differential is a highly prized item, they have to be factory standard under the stock rules and not many cars have them. The introduction of the LSD to the Cooper-S (in 2005) was supposed to be the cause of some angst in the autocross community as it caused the Cooper-S to be unexpectedly dominant in its class and got it moved to a different class. An e-diff is not regarded so highly as a physical LSD, but I had hoped it would be an advantage. If the e-diff is a problem, my plan b is that next years rule will allow it to be disabled (but not this year's rules).

Now I'm wondering if I should change plans and continue to run Tristan as our autocross car. Having three cars is less than convenient (as we have a 2 car garage). I'm not sure if that's practical, but a 0.66s would be a very large factor, not one that's easily found. That 0.66s is the difference between me coming ahead of Rob, or behind him. 0.66s can quite easily cover 3 or 4 places in the more popular groups. Our current plan is to get Bertie an alignment to help with the tire wear issues, he's going to the shop tomorrow, we'll also get him weighed at the same time. Any weight difference between Tristan and Bertie will be interesting, but I'm already satisfied that the power/weight ratios are very similar. (And power/weight is the important thing.) The factory spec on Bertie is for 3more HP than Tristan, but 3hp can get lost in specs easily.

If the 0.66s number is correct (a big if), it also suggests that our regular autocross wheels (the 16" ones) are better than the alternate ones (the 17" ones). This is a much more uncertain calculation, but if you do take out that mythical 0.66s, Cathy got much closer to my time (by 0.075 seconds) than she'd ever done previously. Its difficult to say how big the difference between the wheels is (without more parallel testing, which I'm now reluctant to do) but I'd guess the difference may be a second or more.

The results are out http://www.sfr-solo.org/solo2/Result...p/round07.html , I came second to Chris, and Cathy came third. This more or less cements the championship with Chris first, me second and Cathy third. There's no one with enough points to come close to us with only two rounds to go. Our order seems pretty set by this time. Even without the mythical 0.66s, I didn't come within half a second of Chris' time, maybe with the other wheels… My time would have put me 4th in H Stock, without the mythical 0.66s, it would have put me 2nd. Looking ahead to next year when H stock and G stock are effectively amalgamated into G Street, my time would have placed me 7th out of 15 with Chris coming just ahead of Brian. Even 0.66s wouldn't help much, it would only put me 1 place up, but another second (tires?) would put me third (behind Chris and Rob).

Overall, I came 92nd and Cathy 101st out of 186 entries (indexed). I was 5.8 "seconds behind", which is pretty good for me, Cathy was 6.4 seconds behind, which is substantially better than she's managed before. Without the 0.66s, I'd have been 70th and 4.8 seconds behind, which would have been amazingly good for me.

Catherine in the Clubman-S came 23rd out of 27 in the Novice class and 174th (indexed) overall, 14.8 seconds behind.

There's video;

My fastest, fun, run in Tristan: http://btwyx.com/Movies/AxJul13OakBT4.mov
Cathy's fastest, fun, run in Bertie: http://btwyx.com/Movies/AxJul13OakCB4.mov
My fastest scoring run in Bertie: http://btwyx.com/Movies/AxJul13OakBB4.mov
Cathy's fastest scoring run in Tristan: http://btwyx.com/Movies/AxJul13OakCT4.mov

The data system in Bertie (the hardwire dongle and iPod touch) didn't do well and seems to be missing lots of the data, so there's no data on Bertie's videos. I was worried the 3rd gen iPod touch I was using wasn't fast enough to do the job, so I want to try this again. I have an old iPhone 4s which would work, or I could try my regular iPhone with a dock adapter.

 

You are looking way too hard at numbers that are probably within data noise. The course was almost certainly faster once it got swept, heated, and rubbered in in the afternoon. Don't factor out that it was your second set of runs through the course too, especially since you are only doing 1 walk.

The valvetronic cars are proven faster, especially from a dig. If you are going to build a car, run the newer one.

 

Noise is the thing I'm worried about, that I'll be chasing a signal that doesn't exist. The data looks very compelling to me, see below for the trend after adding the 0.66s fudge factor. The course was pretty well swept by the time the morning run groups finish, probably 2/3rds of the runs that happened had already happened. The "morning" runs were also at the hottest part of the day, it had cooled down by the time the afternoon runs happened. I know we're going to get faster as we go on, that's why I'm looking at the trend, not the absolute times.

 

I'd plot a few previous events and see if the trend lines have a similar slope. 4 runs apiece just doesn't seem like enough to me. I'm a fairly good driver and I'm usually still chipping time off after 6 runs.

For another "courses and experience on them do unexpected things" anecdote, at the NJ Pro this year it was in the high 40s with gusty winds to start off Sunday morning after a warm afternoon Saturday. Everyone was saying it was going to be tough to find time and that the leaders might be safe. This proved to not be the case at all as people were flying out of the gate and many positions changed hands. Yes, it was colder, but the course was rubbered in and it was 5th and 6th cracks at the course for most drivers.

 

Not sure why you say that, we were chipping away through all the runs. As for other events, I plotted a few BMW events, they're more comparable as they have 6-8 runs, rather than 3-4. The times are normalised to the slowest time (usually Cathy's first).

I usually start off faster, and Cathy catches up a bit. In 4 run events, my second is most often my fastest (in 4 out of 7). Cathy is usually quite consistantly faster with each run.

 

Today was our last event of the SCCA's regular season. It looks like I'll definitely be second on the championship. Originally we had planned to do the BMW club's event #5 out at Marina on Saturday, but a new event was inserted into the SCCA's calendar. Almost everyone was most excited to have the opportunity to run at Crow's Landing. This was an ex-NASA airfield with humongous runways. There had previously been events there, but not for many years. There had been delicate negations with the county about getting back to the venue. There is hope that if this goes well they might be able to bring national level events there. Unusually there was a limit to the number of entries and you had to preregister (using Motorsportsreg). The limit was 250, and there were 244 entires.

We weren't too excited as Crow's Landing is in the Central Valley of California, which is a most unpleasant place in the summer, the average high for 11th August is 98 degrees. Compare that to Marina with an average of 72 degrees. A little further down the central Valley Bakersfield have given up on running daytime events in July and August, they've been running night events.

The SCCA had originally scheduled the last event of the regular season for next weekend at Marina. With the Crows landing event and other events happening next weekend near Monterrey, they decided to cancel that event and have another event at the Oakland Coliseum for the following week. We're currently planning to be on vacation then so are going to miss it. So we're now done for the regular season, but will be back for the slush season in the autumn, but the schedule for that has not currently been published.

In the novice championship, I'd worked out that I had to win the next two events to even just tie with Chris (assuming he came second). With is not being able to make the Oakland event, it looks like Chris is now going to win the championship. We'd much rather have run with the BMW club this weekend, but with the championship on the line, I just had to give it a go. Cathy is safe for third in the championship, no matter what happens at these two events.

After our comparison of the MINIs at the last event, we took Tristan to this one. This will be Tristan's last event. I decided the reason why Tristan was faster than Bertie was because of the oversteer he's developed. We don't know why the oversteer appeared, but its something you can tune into a MINI, so we'll be working towards that with Bertie.

Also unusually they didn't publish the run group order until early last week, by which time they knew how many entries they'd have so they could balance the run groups. Thankfully, we were in the first run group, when it would hopefully be cool. We'd have to work group 3 when it'd be hotter. There were 6 run groups in all. In the end its been unusually cold in California recently, it was only 90 degrees today at Crow's Landing (and 60 degrees at Marina). Its was still much to warm for our liking.

When we got to the site this morning, we weren't quite sure how things were being managed. We parked in the paddock, a long way from the motorhome, then went to find registration, which was next to the motorhome. We found the course was at the intersection of two of the huge runways. The course ran off down one, came back ran off up another, came back ran a long way down to where we were parked and then back again. It looked like a really long course. They'd had a test and tune event there yesterday when they has two course, which had been joined into today's course. Both the test and tune courses ran 40 seconds each.

We eventually got registered, and we found where they were doing tech inspections. Unusually, they were not doing tech on grid. I went to walk the course and Cathy went to prep the car and get teched. The plan was she'd catch me up. When I was about half way around the course they announced it was closed for walking, before Cathy managed to get to start walking it. It took me just over half an hour to walk the course, it was much too long. It was also not very exciting, lots of mainly straight bits punctuated with a slight twiddly bit. Most of the elements of the twiddly bits were spread far enough I'd usually discount them. At the speeds we normally go, they'd be non events. There were lots of wide open bits and I expected we'd be riding the limiter a lot, or needing to change up into third. While I was walking, they announced the course as being 6200 ft long. By the time I'd finished my walk, I'd forgotten what I'd concluded about most parts of the course. I'm thinking I needed to make notes.

As I'd walked the course and Cathy hadn't, I went out first and gave Cathy a lift as her orientation. I had made a note that I'd been confused by a few of the first cones. They initially look like a slalom, but two of the cones are pointing in the same direction. So being mindful I might misread the course, I promptly misread the course in the other direction and went the wrong way. I got a 103.9 (and a DNF) which seemed like a reasonable first time. (That's one hundred and 3 seconds, not one minute 3.) I scared Cathy with the speeds I got unto going around some of the twiddly bits. I was as I'd predicted hitting the limiter a lot. So the speeds were substantially higher than normal, and with the course design of a fast section with a twiddly bit thrown in the middle, you approached some sections at quite daunting speed. It didn't bother me from the driver's seat, but it did bother Cathy. That's the first time she's expressed disquiet about safety when we've been driving.

Then it was Cathy's turn to drive, and I got a lift. Things went well up until the final corner, when she went the wrong side of the cones at the exit gate, so got a DNF, right at the very end. Looking at the video it does look remarkably like a reasonable way to go. You have the timing equipment on one side, with a yellow cone, then a wall of cones to mark the other side of the gate. It looks like a gate, but is in fact the wrong side of the wall. There were a lot of DNFs on the first runs, and I notice on later runs there was a cone put in the way to tell you not to go that way.

When I could persuade the lap timer to work correctly, I was trying to work out what I should do for my next run. Unfortunately the lap timer was having fits and only displaying the data intermittently. After Cathy's first run it displayed an alert saying something had gone wrong and I should contact the author to tell him about it. So I deleted the data for the first two runs in the hope that it would see sense for the next few. When I was trying to work out was when or if I needed to change into third. I didn't come to a conclusion before my second run, so I went out for the second run and just ran in second. I got a 100.3 Unfortunatly Chris had already got a 100.something as well with his first run.

Studying the data I decided I'd change to third before the first sweeper and keep it in third for the rest of the run. On the second run I was hitting the limiter in a lot of places. I even hit the limiter before the first sweeper. The course goes off down one runway, around the not a slalom and then takes a 180 degree sweeping turn around to come back again. There were such sweepers at the end of each arm of the course. In second gear I was hitting the limiter almost everywhere and I wasn't falling below about 4k revs. With that rev range I thought I might be able to get away with changing up to third and not changing down again. If I where in third instead of second that wouldn't fall below 2600 which might still be feasible. I'd concentrate of trying to keep up my speed through the sweepers to limit the damage. We only had three runs, so I only had this one chance to get this right. Ideally I'd have tried it in third and then used what I learnt to come up with a better plan.

It didn't work, I got a 101.9. Looking at the data, I didn't manage to go any faster except on the run back to the finish. For that section you came out of the sweeper around a solitary cone, through a gate (which might as well not bee there), then into a not quite a slalom. It was a slalom, but the cones were offset to make it not such a problem. The offset wasn't quite enough to drive a MINI straight through, but with the cone spacing it was almost like it wasn't there. I got up to about 63, where the limiter is 58 in second. If I had another run, I'd try a downshift going into each of the sweeper and the bottom of the 'Y'.

Cathy's second run was very leisurely 109.3, she was trying to work out what the right way around the course was. She was quite puzzled how she managed to miss the exit gate, until we reviewed the video and saw they'd added a cone. Her third run was a 106.2. This was still good enough for third on the day. They had live timing available via Wi-Fi so I could see how things were shaping up. Though when I last looked, they'd forgotten to apply her index to her time, so she wasn't shown with her third place. I was second with my 100.3, Chris got a 98 and a 97. After applying the indexes, he was still 1 second ahead of me. There was only one H Stock entry and no G stock entries, none of the regulars turned up, so I've nothing to compare myself to there.

The powers that be were very keen to see that the event went well, so they'd be able to hold further events there, with an eye to having national level events. There were strict rules (like no alcohol) with a sheet of rules given out to everyone. There was also talk before the event that we should be sure to take one particular entrance to the site (and not the route than Google would suggest). Cathy signed up for gate waiver for her work assignment. This is usually a very easy assignment, usually waiting around for something to happen. There was also a pop up tent for shade at the gate, which made it especially attractive. I'd signed up for tech and wasn't expecting much to happen.

As it was the Modesto Bee, the local paper had covered the Saturday event: http://www.modbee.com/2013/08/10/285...fuel-need.html (the print edition has a picture of C Mod open wheel race car.) This caused quite a lot of interest locally, and Cathy had to deal with a flood of clueless newbies. Of course everyone entering the site has to sign the insurance waiver. This was a shock to some people. There were also cars trying to get into the site from every which way, not just the county approved route.

So that's the end of our regular season. We'll be back for the slush season later in the year, there are also a couple more BMW club events for the year. Though we'll miss the next one as we'll be on vacation. For the rest of the year I'm planning on running according to the rules for next year (in G street), which will bump us up to STF. That is if the new wheels I've ordered ever arrive

I have video:

My best run: http://btwyx.com/Movies/AxAug13CrowsBest.mov (no data, the lap timer played up)
Cathy's best run: http://btwyx.com/Movies/AxAug13CrowsCBest.mov

The site was very dusty, you can see the outside cameras are looking a bit fuzzy because of dust on the lens. You can see some more the dust here:

 

Mark, who just happens to be head of tech for the local SCCA, also takes pictures at these events. He took a picture of his appearance on the cover of the Modesto Bee: http://markm.zenfolio.com/p897646359...E06A#h6c31e06a

 

And a picture of the course as seen by the lap timer on my third gear run:

 

Wow! What a course!

Thanks for the great read as usual.

Cheers,

Charlie

 

There's been a lot of discussion about the event on the local forum, almost all of it positive. I don't want to rain on their parade, so I've refrained from commenting there. But I didn't like it. It was too long, both too simple and too complicated, too fast and totally not suited to the MINI's setup.

The too long has been addressed, in case they never got back there again, they wanted an epic course which would be remembered. Its been suggested that any future course there shouldn't be that long.

It was too simple as I said it was long stretches of straight punctuated with twiddly bits. It was too complicated as you couldn't appreciate the whole course, at least not from one walk. It was too long to walk it enough to learn it. The long narrow(ish) runways constrained the course into a long narrow format, you have to have enough separation between cars running in opposite directions of the course.

The rules say that speeds of the fastest cars shouldn't exceed freeway speeds. Its been suggested that the fastest cars got up to 85 or more. Now you might say that's normal freeway speeds, it isn't legal freeway speeds. Needing to use 3rd so much in the MINI certainly didn't help. I was surprised that Cathy was disturbed by the speeds we were reaching.

I've set the MINI up with the assumption that courses won't be that fast, particularly the choice of shorter tires. On courses with reasonable top speeds, the MINI is not challenged by top speed. There have been several courses in a row now which have been high speed courses. I sometimes think I should bring an alternate set of tires just in case there is a fast course. Algy's wheels have larger tires, I'm thinking of getting 225/45-17 tires for them (for track use), they would have been a much better fit for this course.

There's at least one other guy out there who's been complaining about the excess of speed. This is the culmination of the problem. The local forums are dominated by people who like fast courses, and have complained about technical courses.

 

The results aren't official yet, but they've posted a spreadsheet with the raw results. They need some major clean up, but the upshot is:

I came second and Cathy came third out of 12 in novice, with Chris coming first a second in front of me. Overall (indexed) I was 115th and Cathy 162nd out of 242. I'm 6.5 "seconds behind" and Cathy 9.5 seconds behind.

 

While I've already started my 2014 autocross season, there's still some of 2013 to finish with. In a couple of weeks I'll be competing in the BMW club's season finale and championship (called the "Top Driver Shootout", TDS). After the last event I was feeling a little out of practice so as Cathy was out of town this week, I wondered about going to an autocross on my own. The Fresno SCCA chapter were holding one of their events out at Castle AFB, so I thought I'd make the trek out there. Cathy had Bertie this weekend, and I'll be taking Tristan to the TDS so I took Tristan.

Our previous experience with Fresno was back in January when we did their autocross school, which was very helpful. And then we competed the next day in their first event of the season at the same venue, which reused some of the school elements. So even though I came high up the results (10th out of 73 by index), I wasn't sure how much of that was my driving, and how much was familiarity with the course elements, which made it less satisfying.

I briefly considered entering in STF as I did last week. As STF ran in the afternoon, that would allow me to get up later and drive down in the morning. But I decided to enter in H Stock instead, so I went down the night before to get there early. That was probably a good idea as competing after a 2 or more hour drive wouldn't have been a good idea, and I got stuck in traffic on the way down so might have been late. There haven't been many entries in H stock at Fresno, only two other events had any entries and no one had competed in more than one event. So entering in H Stock would probably mean I win the Fresno championship, though they don't give you a trophy if you haven't competed in enough events (you need to compete in more than half the events). Given how hot it can get out in the central valley (85F forecast), running first thing when its still cool sounded like a good idea.

Looking at Google Maps http://goo.gl/maps/mR152 for the site, I did wonder if the event were being held on the 1000ft wide apron, which would make for some amazing courses. But no, its being held on the small concrete area to the side. When I got there, after the GPS sent me down a road which was blocked and then being surprised by a http://en.wikipedia.org/wiki/Avro_Vulcan (Britain's Nuclear Delivery bomber), and an http://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird at the http://www.castleairmuseum.org/ondisplay.html (which was closed). The concrete for the course was pretty small, and it looked in pretty bad condition. It was very bumpy, and bits of it were crumbling. The later runs involved avoiding the chunks of concrete which had been dug up.

Walking the course, it was an interesting course. From the start line, it went straight into a slalom. The ran along the far side of the concrete, without much deviation, I wonder if that would need third gear. Then into a tight 180, where I wondered if I'd need first. Then into an optional slalom (i.e. you could take the slalom either side as you wanted). Fresno seem to be fond of the optional slalom, they taught it in the school, and it featured at event 1 as well. I'm not sure I've seen one anywhere else. Usually the option is there to make you think and to make a trade off. Usually its easier to enter the slalom one way, but that makes the exiting it tricky. If you enter the other way, the exit would be easier. But there was no obvious trade off for this slalom. Entering the easy way meant you exited it in a reasonable position. The slalom was also sufficiently well spaced the MIN would hardly notice it was there. Coming back down the course, it became evident why it was an optional slalom. The course looped. You came back and ran the slalom again. This time it made sense to run it the other way.

I was in run group 2, so I had to work run group 1. Fresno do worker sign ups differently, unlike the San Francisco chapter, there's no form with the different work assignments, you just sign up and they assign you a job. I got assigned as back up time keeper. I was to notice cars times with a pen and paper, just in case anything happened to the computer entry. It was a good job I was there as the scorer had forgotten to hook up the timer to the computer at first. He had to copy my first few entries into the computer manually. That's the first time in the trailer, it was surprisingly cold out there. The weather was typical, bright and sunny, but the air was still cool, 52F. So out in the sun you're baking and running around in shirt sleeves. In the trailer out of the sun, you bundle up and shiver.

Working timing did mean I could keep an eye on the times going by. I kept a not of the best indexed time, and then worked out what I'd need to do to match it. I worked out I'd need a 54.2, and if I wanted to come within 4 seconds of the time, like I manage locally I'd a 60.5. I then forgot what I'd calculated and started thinking I'd need a 53.2 to match that time.

My first run was not too bad. I braked too early at the far end, using the wrong gate as my braking point, so I didn't need third, but it was otherwise reasonable. It was a 56.0, though my timeslip said 56.6. That was definitely better than my 60.5 target, and a good way towards the 53.2 target. Definitely a good start. For the second run I braked in the right place, but was still not hitting the limiter at the far corner, on my best run I was still 50 revs short of redline there. Then I had trouble with the following 180, and also with the 180 at the other end of the slalom. I'd continue to not get those right for the rest of the day. I got a 55.4, even better.

For the third run I really flubbed the 180s, so my time slipped backwards. My fourth run was pretty good, though the second time through the 180 at the end of the slalom wasn't that good. On the video I'm way wide. But it was good enough for a 54.6, and my best time of the day. As I didn't have any competition I Was feeling quite relaxed about the whole thing, the only thing pushing me was me. I still managed to flub a couple of runs (the 3rd and 5th) by trying too hard. Now that the results are out I see that my 54.4 was good enough to be only 0.2s behind that top time forma the first run group.

For the ride home I didn't fancy getting stuck in heavy freeway traffic, so I took the more direct, but slower route over the mountains: http://goo.gl/maps/APfFl past the Lick Observatory on Mount Hamilton. I stopped off there to see the 120" telescope. The road to Mount Hamilton was fun, the road down from Mount Hamilton is not nearly as pleasant.

The results are out http://www.fresnoscca.com/results/20...vent15_fin.htm and the indexed results: http://www.fresnoscca.com/results/20...vent15_pax.htm showing me 7th out of 51. That proportionately as good as my January result (top 13%), and considerably better than I've done locally (last week was top 32%). I think there are some stronger drivers in the local chapter.

I have video of course: http://btwyx.com/Movies/AxOct13FresnoCastleBest.mov

No pictures of me driving, but here's a picture of the Vulcan, SR-71 and 120" telescope.

 

Yesterday was the BMW club's season finale, the "Top Driver Shootout" (TDS), down at Marina airport.

The qualification for the TDS was to have run 3 events over the season, I qualified, but Cathy didn't thanks to a couple of clashing events. The TDS was limited to 60 places, and it sold out in 19 hours, I made sure to get in early. You also had to drive a BMW or MINI to run in the TDS, at the normal events they don't care what car you drive, but only BMW/MINIs are eligible for trophies.

As this was serious stuff, I'd decided to take Tristan, who's currently proven to be our fastest car. I also finally managed to find some wheels in 15"x6.5" with an eye to next years "Street" category (in the SCCA) rules. I put even wider tires on the new wheels in the hope that it'd help. The new tires are BFGoodrich G-Force Rival ("Rivals") in 225/45-15 size. Rivals are the latest hot tire everyone in autocross is trying. With the new tires I needed to find some new tire pressures, so I'd been measuring tire temperatures again going to and from work and came up with what I thought the right pressures were. Then I added 3 psi, with the thought that if they proved to be too high I could more easily let pressure out. (I ended up with 42 front and 39 rear).

The TDS format is:
You'd be randomly assigned to one of two run groups.
(Only two drivers per car are allowed, one in each group).
When you weren't running, you were working the course.
The two groups would run in the morning, with the course running one way.
There was a catered BBQ lunch and trophy presentation for the season
The two groups would run again in the afternoon, with the course running the other way.
The two times were indexes and added together
The top five drivers from each group would then go onto the final shootout. The course would run backwards and the loop back on itself.
The person with the best indexed time in the shootout wins.

I had no illusions that I was going to get into the final shootout, but I wanted to give it a good try.

I drew run group 1. The morning's course ran from left to right (as you looked at it from the grid). It was an interesting course with several tight almost circular sweepers, a few tight twiddly bits and a slalom where one cone seemed to be out of place, to make it even more difficult. The course entry was unusually narrow, and went around three sides of a square. It was almost custom designed to help a MINI. I thought I'd run through the narrow start in first gear and only change to second after launching from the last right angle into the wide sections.

At the start the timing lights were around a 90 degree corner for once. When there's a bend before the lights the start is relatively easy, the corner limits you speed, so there's no need to perform a drag race start to get to the lights at the highest possible speed. The BMW club usually does straight starts, necessitating a drag start.

I went out and ran a 52.something, the timer wasn't displaying the times, so I didn't know what came after the 54. This seemed like a reasonable start. Tristan was being a bit of a handful again, and I got very sideways in the sweeper on the bottom left of the course. There were also a few other area where I thought I messed up, and unusually could remember where I was having the problem (though I can't remember now). So for the second run I went out to correct those errors. I still got a bit sideways, but I came in with a 51.6, a decent improvement. I was listening to the times of some of the top drivers and I could tell I was still a ways behind them, even accounting for the indexed times. The third run wasn't side ways, but I messed up worse, so came in with a 51.4. I managed to change up to second before I meant to. Then for the final run of the morning, things went largely right, and I got a 50.0(10) which seemed like a very good time.

Then it was time to work. By the time I arrived they'd run out of regular work assignments, and I can't run after cones, so I had a nebulous assignment of "supervisor", or "scrutineer". I just wandered around looking official (I had on the regulation fluorescent jacket) and talked to people. I found Paul, who was in the only other MINI there, and talked to him. His first run seemed very hesitant, and he admitted to getting lost, but it wasn't that far behind my first run. I kept tabs on his times during the mornng, and he never did equal my time. His MINI has a slightly higher index than mine which pushed me further ahead of him. Talking to others running in the group, it seemed like getting lost was a common theme. I'm not sure why that was, it didn't seem like a particularly difficult to follow course to me.

Then it was lunch, they had a local BBQ restaurant cater the meal, not the best BBQ ever, but quite palatable. Lunch was a good thing, I'm usually ravenous after an autocross, I didn't want hunger distracting me for the afternoon. There was also a presentation of the regular season class trophies. I'd come 5th in C class, and there were trophies for 1st, 2nd and 3rd, so none for me.

After lunch there was time for a course walk to examine the course on its backwards run. I deliberately not considered the backwards runs on the morning walk, so as to not confuse myself. The course now started from a "side street", so there was a kink immediately after the start. The lights were also really close to and a straight shot from the start line, so it'd be back to a drag race start. I was wondering about the finish, if they kept the really narrow square part of the course, it could be very tricky. But they'd moved the finish lights to just around the last (now first) right angle. This end reminded me of a previous BMW finish which was just around a corner, where I spoiled my best run by hitting two cones at the finish. The lights were so close to the corner I wondered if it would be better to approach the corner directly and try to cross the lights sideways rather than take the extra time to widen out the approach to the corner and lose time.

I went out for my first run and got a 48.8, which seemed like a good time. People's times seemed to be generally faster on the backwards course than the forwards course. On my second run I coned the awkward out of place cone on the slalom, the run would have been slightly faster but for that, 48.8. I got surprised by some cones, coming off the slalom and round the corner there's an apex cone which leads on the portion which points back towards the start. I got too earl an apex and was surprised by the wall of cones I was in danger of running into. The around the next apex cone I did the same again. I lost time in both those places, I would continue to get those wrong throughout the afternoon. At the finish my sideways exit was putting a lot of strain on the front right tire, I could hear it scraping off the corner. I hoped I didn't have a flat spot.

The next two runs were good improvements, I knocked off 0.8 each time, I ended up with a 47.3 which seemed like a very good time. I must have coped better with the two apex cones I was having trouble with, but the finish sounded just as bad on the last run.

Next it was time to work. I had the same assignment as before, so had some time on my hands. I looked over the list of times from the morning and saw I was in 8th place overall. It was looking possible that I might actually get in the shoot out. Though its difficult to tell how much danger of that there was as the results didn't note if you were in group 1 or group 2. In theory its possible to come 6th overall and still not get into the shoot out, if the 5 better drivers are all in your group. That would be very disappointing if that were you, but it does make sense. You can never tell how conditions change and make things faster or slower, so its only fair to directly compare your times against people running in the same group as you. There was a column where people were writing in their run group, but not all of them had been populated, it would be close.

Meanwhile in group two, Paul in the other MINI was not having a good day. His first run was almost a second slower than mine and for his second he DNFed with an even slower time. He ended up a second behind me.

Now it was time for the announcement of who was getting into the shoot out. The results didn't have run groups on, so they called your name out in order and you stood on one side or the other until there were 5 on each side. It looked like my group was the strong group, of the first 5 names called 4 of them were in my group. The other was only in the other group because they were sharing a car. This was the Tsang brothers (Justin and Mack) who regularly get high in the SCCA results, they were driving the car they'd competed at (SCCA) Nationals with. Luckily I was 6th and filled out the final spot in my side of the grid. There was one person who's name was called but didn't get into shootout because he was only 6th in our run group. I could imagine how disappointing that was, I was just glad it wasn't me.

Now I had an unexpected extra session to run. The batteries on the outside "cone cams" were showing empty, so I didn't know how much recording time I had left. (The internal cam was fine, it runs off the car power.) I didn't have the charger with me, so i decided to only turn on the cone cams for the actual runs, not just let them run like I usually do. I also decided not to turn them on for the first run, with the expectation that my first run would not be the fastest.

The course was now run both ways. You ran the afternoon backwards direction, went around a square where the morning start had been, ran in the forwards morning direction, then came back and finished at the morning finish. You could run the turn around either way. I went out and did what seemed like a reasonable run for first run, 96.6. We hadn't been able to walk the the new bits of the course, so I'd gone a bit gingerly around the turnaround, but the rest of the run was reasonable. For my next run I tried to be more aggressive with the turn around, and overall, but I again got surprised by the same apex cones I'd had trouble with in the afternoon and my run was slightly worse. Now I had one more chance, I decided I'd try the turn around in the other direction. This would give you a straighter course coming back. I again flubbed the two cones which had bedeviled me and got a slightly faster time, but not as fast as my first run.

Then it was time for the trophy. The Tsang brothers were 3rd and 2nd, but for the third year in a row the winner was Praneil. He had been getting some mighty impressive sounding runs, but only 0.133s faster than Mack. I came 10th, over 1 second adrift from 9th place, 4.3 second back from Praneil. In the heats I'd been only 2.7 seconds back, so my lackluster showing was a bit of a mystery. I did make the errors I'd noted, but I didn't think I did two seconds worse. Though if I'd have progressed at the rate I had in the heats, I might have made up those two seconds, instead I went backwards. Maybe I was tired, this was more autocross than I'd ever done in one day before. During the last run, I did notice I'd left the stability control on, maybe that had something to do with it. (Tristan's stability control has been beaten into submission so much I can make three autocross runs with it on before noticing.) Given how lively Tristan was in the heats, this might be a factor.

This is Tristan's last event, our focus now is to make Bertie as good as Tristan is.

At least until the final shootout, this is the best I've ever done at an event. Now I'm not sure how much is due to me, to Tristan (rather than Bertie), or to the new tires (and wheels). Maybe I'll have some idea next week when we'll take Bertie (with the new tires) to the second round of the SCCA's slush season. I'm not sure if the tire pressures were right. The temps and wear indicate that they were a little overinflated, but the outer corner of the tire wore quite a bit (at least on the front), a little more pressure might help that.

I have video of course.

My morning best: http://btwyx.com/Movies/BMWTDSAMBest.mov
My afternoon best: http://btwyx.com/Movies/BMWTDSPMBest.mov
and my shootout best: http://btwyx.com/Movies/BMWTDSShtBest.mov Though this one doesn't have the cone cams, as I wasn't expecting it to be my fastest run.

There was an official photographer out on course taking action shots:

 

Congratulations on a great season. Thanks for the posts.

 

very nice run! car looks great too. what are the set up differences between tristan and bertie that makes them so different?

 

There's nothing deliberatly different, they both have sport suspension. The way the oversteer grew, I suspect the shocks are going off. They're the original shocks. My attempt to measure the springs suggest the springs may be different, but I'm not sure.

 

gotcha - staying on this setup for next year? I'm hoping to go "all out," hope what I have planned turns out well

 

For the rest of this year an next year we're going with Bertie. I've been thinking of asking FatCat what they can do for me.

 

Yeah I shot them an e-mail recently... pretty pricey

 

It took a while for him (Fat Cat) to get back to me, but he sure knows his stuff. Take a look at his videos if you have some time.

If you can't afford his custom setup, consider his bump stops. I can't wait to try out playing with the spacers on the front struts to tune the KONI setup I have.