I carefully edit the video and only publish a small part, about one lap is enough. The rest of it is useful for reference.

The good thing about HPDE is you can go as fast as you feel comfortable with. If you don't want to go that fast, you don't have to. I have said that lady drivers have been known to suffer from "testosterone deficit", or maybe the average man is suffering from testosterone poisoning. My wife is like that, she finds a speed which is comfortable and doesn't want to go any faster. I'm always looking to go as fast as is possible, now the wife is catching up, but she doesn't look like she's going fast.

 

That's the stereotypical thing: Women drive with more smoothness and less aggression, while men drive with more aggression and less smoothness.

It is true in many instances, though I personally know of some exceptions. In fact, I'm married to one!

The decent female drivers I know have generally kept the smoothness while improving the aggressiveness. And it doesn't look like they're going fast, even when they are. I remember one friend autoXing my "other car", and me being very frustrated watching her. "Come on, push the car! You won't hurt it!"

--And then I heard the lap time. She had beat me by two seconds, out of about fifty seconds. Schooled me right proper, she did!!

In fact, that car has won its class in at least three national competitions so far. None of them with me driving... :D

 

Are we ever going to see you, or your wife it seems out at the track or an autocross?

 

Testosterone poisoning, LOL, is that what's wrong with me.

 

I'm eventually going to get my "other car" more reliable again, and start running it with the PCA again.

I hope my wife decides to run with Checkered Flag again; she enjoyed the track days with them in the past.

 

Sunday was MINI Thunder up at Thunderhill. Being a MINI only event I decided to take Bertie, with only MINIs to content with he wouldn't be totally out of his league. I was in the advanced group and Cathy was in the intermediate. I also volunteered to coach, which I've never done before.

This being a MINI event it was also a social event. The night before was a casino night in the Thunderhill clubhouse. We weren't playing with real money, but the chips could be swapped for various real stuff. Last year, I won a lot of chips, but the prizes were all gone before I tried to cash in. This year I won at craps again, but went to checkout the prizes earlier. I got a large print of the group photo from last years event which was priced at "$2,500".

Here's a handy track map.

The last time we were at Thunderhill in a Cooper (not an S or JCW), my best lap was a 2:30.1, but I was on an even better lap which got interrupted by the end of the session. Timed from turn 10 to turn 10, I got a 2:29.5. That was from before we started running the Bridgestone RE-11 tires, which were worth about 1.5s, but we're now running RE-11A tires which seem to be about 1.5s slower. So I was thinking about a 2:29 would be a good time. The RE-11A tires are larger than stock, which would hopefully help with the gearing. I'd be able to get going faster before changing up into 4th, hopefully being able to avoid changing up in several places. Down the hill from 9 and up the back straight to 14 were where this might matter. I'd still be changing up on the front straight and into turn 8.

I was also going to try a different line at turn 5. The classic line is a typical line, stay to the right, brake, then turn in. So you're going slow from your turn in point, to the apex, but you get a fast exit. But at turn 5 gravity helps you on the exit, and you can't get going very fast as you have to get around turn 5a so the exit speed doesn't help you much. So I was going to trade a fast entry for exit speed. I'd aim straight at the apex (which is the only part visible as you approach), brake and turn in at the apex. It'd be slow on exit, but that shouldn't matter much. Its much like the line I've been using at the Corkscrew at Laguna Seca.

I was also going to be concentrating on turns 14-15, 9 and 8. I'd finally worked out a good line at 14-15 at my last couple of events, so I was going to practice that. I'd take an early apex at 14, run wide over the rumble strips between 14 and 15 and get a late apex at 15 for a good launch up the front straight. At 9 I was going to be taking an early apex and getting close to the exit berm. In Tristan I'd been able to take turn 8 without lifting, but it took me all day to work up to that.

The weather forecast was promising rain overnight, so I was expecting a damp start, but when we got to the track it was dry and brilliantly sunny. The weather was just about perfect, sunny, but not too hot. It was only got in the 60s. It was still pretty chilly when I got onto track for the first session, my group was first on track. For the session I got consistent 2:34s, which seemed like a good start for the first session. I hardly saw any other cars on track. I overtook a classic Mini on my last lap and I was overtaken on my cool down lap.

Cathy was out on track with the third group. For once we weren't scheduled to be on track back to back, and there were other sessions between each of our sessions. While she was out I went to grid to find a novice to coach. I found Michelle. We know Michelle from autocross, we'd seen her at the event the week before, where they'd mentioned they were going to miss the event this week as they were at MINI Thunder, so were we. We'd bumped into Michelle and her husband Rob at the casino night. Rob wasn't driving due to his arm being in a sling. Rob was experienced at both autocross and track, Michelle had never been on track before. We got on pretty well. I drove her MINI for a lap to get her oriented, then she took over as I talked her around the track. She did pretty well.

Immediately following the coaching session it was my turn to run again. I was a little late on track because of the change over. Because I was in such a hurry, I managed to not turn on the cameras, so I have no video of my best lap. I do have data to tell me it was my best lap. I started the session off with two 2:30's and a 2:29.8. So I'd made my target for the day and it was only just 10am. I was never quite that fast again, which seems to be typical these days. For the rest of the day I made consistent low 2:30's. I also saw remarkably little other traffic. The same few MINIs would pass me (mostly JCWs or GPs it looked like), but I seemed to be keeping up with the majority of the Cooper-Ss.

For my 4th session I gave Michelle a lift. I'd been coaching her all day, and she'd been doing very well. I'd started off talking her around the track, pointing to every turn in, apex and track out. For the thirds session I asked if she wanted to try it without commentary, she opted for one guided lap, then I'd let her go without help. She did very well, she did tend to brake a little early and thus was a bit slower around some corners, but I didn't need to say much, apart from some encouraging words. So I suggested I give her a lift for my session which was immediately following that. I said she should take any notice of some things, like my line through 5. For her fourth session I wasn't sure she needed a coach any more and suggested she might like to try solo. She wanted me to coach for that session, but missed the final session due to just being tired and achy. A track day will do that to you.

For my last session I was stopped before getting onto the track and asked if I wanted to give someone a lift, so I did. They were again giving rides to people who turned up. I gave a couple of rides last year, but hadn't noticed it this year. Maybe as I was a little late, all the people who wanted them already had a ride. For the session I got several 2:31s which are the best laps I got on video. My passenger was quite appreciative.

Throughout the day I was working on 14-15 and when I got it right it felt really very good. I'd set the steering and plant my right foot and the corners would just flow effortlessly. I was working on 8 but I never got to where I didn't lift. I got to where I lifted just briefly on entry and then planted my foot again. I think I could have done it if I didn't lift, I just didn't feel like testing that. The data shows I was going around the corner just as fast as I was in Tristan when I didn't lift. I think Bertie is slightly faster than Tristan was. I used the line at 5 as I'd planned, but never tried the more conventional line to compare it to. Comparing it to my best lap in Tristan, the new line was maybe 0.1s faster, though its difficult to say for sure. I found I still had to change up to 4th down the hill from 9, but I was just shy of hitting the limiter on the back straight.

Cathy was having fun, she says she wasn't catching much traffic. Though reviewing the video it looks like there was traffic at times which may have held her up. For the most part she kept up with the cars in her group and got some compliments from her group leaders. She managed to run about as fast as she has in the the JCW, or even faster. Her previous best lap (in Algy) was a 2:35.5, but her next fastest was a 2:39.7. She got a 2:39.1 and lots of laps in the low 2:40s. For one session she got a coach to help work on turn 3. They also did a lead-follow for a couple of laps with the group leader in his spec Miata.

I have video of course. My best lap on video (from the 6th session): http://btwyx.com/Movies/MINIThunderBest.mov

Cathy's best lap (with no data unfortunately): http://btwyx.com/Movies/MINIThunderCBest.mov


Here's the group shot. (We're third form the left, 5th from the back).




Us on the parade lap after the group shot:




Me practicing my new line through 5.




Cathy doing the lead-follow.

 

Nice. Good to see you getting out and on a great looking day. I like the dual video and the data overlay.

 

Sweet photo. I wanted to go, but no way I was getting out of this project to attend this event. Looked fun

 

The day was as close to perfect as could be, it was great.

The video is our autocross setup repurposed. For autocross we have a "cone cam" on either side. For a track day, they don't quite have enough battery or card space to last a whole day, so we have one each. I like a rear view for when I'm in an open passing group, Cathy likes an "apex cam".

The data, as usual, comes from Harry's Lap Timer. Though now RaceRender has a Mac version, so I can do the overlays on my Mac. (Harry's will do this with a little effort as well.) Its a bit easier to use and more flexible.

 

Thanks as always for the vicarious thrills!

Cheers,

Charlie

 

Sunday we were at Laguna Seca with Hooked on driving. February has been a very busy month for us, an event every weekend, and another one next weekend. We might have preferred a day later in the year when we weren't so busy, but I'm short of vacation time this year, so a weekend was useful. I wanted to try out Bertie, who now has the full autocross suspension upgrades with custom shocks and an adjustable rear sway bar. Given Bertie is so slow, I wasn't expecting lap times much better than 2:04, I wasn't comfortable running in the advanced group. (Algy is already the slowest car in advanced, and he's about 10 seconds faster.) So I was in the B intermediate group again. The problem then was what should Cathy do, she decided to run Algy in the B group as well.

Obviously, I've never run Bertie at Laguna before, but I wasn't expecting his lap times to be much different than Tristan's. My best in Tristan was 2:01.3 on Bridgestone RE-11 tires or 2:03.5 on Dunlop Star specs. Cathy needed the regular track tires, and I didn't want to run our autocross tires on the track, they're a bit short for track use and I didn't want to heat cycle them too much. So I got a new set of wheels and tires which would be suitable for track use, but might also work for autocross, which gives me an opportunity/excuse to test different size of tires for autocross. I got some Enkei RPF1 wheels in 16x7" (which are the same as Algy uses, just an inch smaller), with some Dunlop ZII tires in 225/45-16 size.

I didn't know how well the new tires would do, and also how Bertie's improvements over Tristan would affect times. He has slightly more horse power, and he also has the EDLC electronic limited slip diff. (Basically it'll brake one wheel if there's a wheel spinning.) The autocross suspension tweaks might also help. So I'd be happy with 2:04s and very, very happy with a 2:01. Cathy's best time in Algy was a 1:59, but she will tend to run low 2:0x, so I expected we'd be running pretty similar times.

There were two things I needed to set up before hand, the sway bar setting and tire pressures. I haven't had a chance to experiment with the rear bar settings. In theory setting the bar stiffer shifts grip from the rear to the front, which should decrease understeer, or eventually cause oversteer. Ideally I'd like some corner entry oversteer which can be countered with the application of the throttle. Last week at MINI Thunder I hadn't felt any oversteer, so the bar probably needs to be stiffer. I might have set it stiffer during the week, but I wanted to try the new shocks without changing anything else, and I also just didn't have time to make any changes during the week. I thought I'd probably have time during the day to fiddle with the rear bar. As we're driving different cars, there's longer downtime between sessions when I could make the change.

The other variable was tire pressures. I'd been doing my usual measuring temperatures after driving to work in an attempt to find where the tires are happiest. They seemed to like high pressures, I'd got to 50psi at the front, almost the maximum spec and they still didn't seem happy. At the back they seemed to want around 40.5psi. On track they'd be working at a much higher temperature, so I knocked about 6psi off than and tried 42/36 with the expectation they'd be around 48/40 hot.

To complicate matters, someone had pointed out to me that tire pressures would also interact with the sway bar setting. Changing the sway bar changes grip by altering the roll stiffness balance between front and back. Tires are most happy when they're evenly loaded. So using them to counteract body roll makes them less happy, so reducing the roll stiffness at one end makes the tires there happier. (Suspension people talk about trying to keep tires in their happy place where they make most grip.) However the roll stiffness is affected by tire pressures, tries also act as springs these springs affect the roll stiffness. Higher pressures make the tires stiffer and increase the roll stiffness, which would tend to make them less happy. Conversely lower pressures make them more happy. This is independent of the optimum tire pressure, that's when a happy tire makes the most grip.

The weather forecast for the weekend was all sun, and Saturday was a brilliant day down in Monterey, the tourists were out in droves, though there was a cloud bank lurking offshore. What I didn't notice in the weather forecast was fog. On Sunday morning the cloud bank had come on shore and Monterey was misty. By the time we got to the track it was downright foggy. I couldn't see even half way across the paddock, I didn't think driving would be possible in that visibility. By the time of the drivers meeting you could see halfway across the paddock, and almost see blue sky, but it was still too foggy to drive. By the time the first session came around, B was on track first, it was still too foggy to drive. So they used a pace car.

The Hooked on Driving truck went out, with its lights flashing, and everyone tagged along behind. It didn't go much faster than 50mph. I was trying to drive a steady 50, which would be boring along the straights, but could get interesting in the corners. Only everyone kept bunching up in the corners. No matter how slowly I went on the straights, I still caught up with a bunch in the corners. It made for an unsatisfying session. This did give me the opportunity to have a look around at the scenery (what you could see through the fog), I'm normally too busy to notice much. At the very end of the session it was clearing up and there wasn't a checkered flag (I checked the video), and the truck came in, most pople followed it. I went into the pits to check the situation and was told the session ended. The next session out went full speed, though there was still some lurking fog at the top of the hill.

Here's the handy track map to refer to:



In the intermediate group you have classroom sessions between driving. I'd gotten used to not having that in the advanced groups. Gordon the group leader talked us around half of the track, there was nothing startling in what he said, but a couple of things he said were interesting. Some corners he described as "set and forget", you set the steering and entry and don't change it till the end. Turns 4 and 6 are like that, the following "straights" are none too straight, and if you get the right steering angle you can get set up for the following kinks without changing anything. In the next download session they showed a video of following David (the head guy) in his race Mustang. David has been a track record holder at Laguna, so knows a thing or two about driving it. That showed the correct way to do a double apex, which wasn't how I thought it was, its a lot like the line I use in Tristan, but tighter. It also showed the exit from the corkscrew (to the left of a black patch) and the entry to 9 (just to the right of a black patch). Also the entry to 10. Instead of getting right over to the left for 10, he angled into his turn in point, it made 10 slightly sharper, but made the setup for 10 a lot simpler.

For one of the sessions, Gordon went out in his Audi with a camera and videod cars through several corners. In a later download he played the video and pointed out the good and the bad of the driving he caught on camera. Commenting on lines, apexes and point bys. He went out on track just in front of me, so I wasn't on the video. I checked the timestamps on the video, one of his laps was a 1:57 and he was catching the fastest cars in the group, almost like they were standing still.

For the rest of the day we got to drive. Though there was a strange incident in the 4th session. Someone at the track (not a driver) felt unwell, so unwell he sought medical attention from the ambulance covering the event. With the ambulance occupied there was no medical cover for the track so the session was black flagged and we waited around for 20 mins before going back out on track. The rest of the day was rescheduled. So our 5th session started late and was very short. It was so short (3 laps) I didn't see the checkered flag (bad, bad), it was there, I checked the video. As they'd had some trouble with that on the Saturday, the rest of the flag stations displayed black flags, making it look like a black flag all situation. I went into the pits only to be told it was the end of the session. Its distressing that I didn't see the flag, I should be better than that.

For the sessions, we gridded according to how fast we thought we were. Faster to the right, slower to the left. In B I'd go for somewhere in the middle in Tristan, and at the fast end in something faster. I at least wanted to make sure I was ahead of Cathy. A couple of times I got gridded higher than I wanted to be, so I pointed a bunch of cars by, then the next car was Cathy. After my warm up lap I'd take off, but still see Cathy in the rear view mirror occasionally. My times were hovering around the 2:03s, Cathy's times around 2:04s.

Out on track I noticed that I was "setting and forgetting" the steering in turn 4 and 6, it was quite neat when you got it right. I'm not sure I was doing that previously. Coming out out of the corkscrew I was keeping to the left of the black patch, I'm pretty sure I was using a tighter line previously. The new entry to 10 made a lot of sense, and I started to use that, it made the transition from 9 to 10 a lot smoother. I decided not to use the line they demonstrated through 9. Even though 9 is probably the one corner I've never got right, the line I'm using, seems not too bad. I'm pretty sure I've tried the suggested line previously and it didn't work. I meant to give their line sometime later in the day, but never got around to it. Part of my excuse is I was tweaking other things (bar and tire pressures), so wanted to keep the driving the same to see what effect the tweaks were having.

When driving a Cooper, with not much horsepower, I drive different lines than I do in a higher powered MINI. I use more "momentum maintenance" lines, that is trying to keep the speed up through corners, meaning an earlier turn in and apex. For turn 2 I'd planned to drive the line I'd been using for Tristan and later experiment with a double apex. After the video of David, I had a better idea of how to do the double apex. It was a lot like the line I had been using, but tighter. That should mean it was slower, but one or twice I nailed it and it felt a lot faster. For a lot of the day, turn 5 didn't feel quite right and I could get it right. I wanted to keep the speed up, and wanted to see at least 4.5k revs on exit. One lap I did something (still not sure what), and I nailed turn 5. I exited with 5k revs. At the end of that lap the lap timer showed fastest lap, with a 2:00, about 1.5s better than my previous best.

During the download, I studied the data and came to the conclusion that it was turn 2 and turn 5 that made the difference. I think it must have been one of the laps I nailed turn 2. The data showed a faster exit speed, which meant I was 0.5s up by the time I got to turn 3. I never worried that much about turn 2 exit as the run to 3 is so short there's not much time to be made. Obviously I was wrong, 0.5s is a huge win. However, turn 5 was an even bigger win, whatever I did meant I made up a whole second by the time I got to turn 6. I'm going to have to study the video and make sure I do the same again, though I'm not planning on getting back to Laguna in Bertie anytime soon.

After the second session I measure tire temperatures, they weren't bad, but I took 1psi out of the front and put 1psi in the back. At the end of the day I took the temperatures again and the hot pressures. At the front the left looked perfect at 49.2psi, the right looked sightly high at 50psi. At the rear the left looked slightly under at 45.2 and the right quite a bit under at 44.4. I think good working pressures would be 49.5/46. I'm going to have to work out what cold pressures will give me that at an autocross.

For the first part of the day, Bertie felt pretty neutral, but no oversteer. So I put my plan into action and after lunch I stiffened up the rear bar to about its medium setting. For the 4th session I went out quite gingerly in case the handling became unruly. Nothing untoward happened, no oversteer. In fact I didn't really notice any difference at all. I think I've just insensitive to understeer, and won't notice a difference until oversteer happens. I hope stiffening up the bar some more will find the point of overseer. I did turn several of my fastest laps after stiffening the bar, including my 2:00.9, which is 1.5s better than any other.

So I'm running faster lap times than Cathy, even though she has 70% more horsepower. This is not a problem, Cathy is happy doing what she's doing, but I was interested in what the difference was. Part of it is timidity, that's fine, she's having fun. I'm also trying to get the most out of the car. I think I'm getting within a few seconds of the best the car can do, any improvement I can make is incremental. It was obvious from the video session than most of the drivers in B weren't getting the most out of their cars, Gordon in his Audi were so much faster than other cars on track. That why they're in the B group. As Gordon mentioned, the jump from B to C (advanced) is the biggest jump in terms of speed. Drivers in C are getting near to the maximum their cars can manage, and doing it consistently.

The other difference is just driving style, again, me trying to get most out of the car. It shows up in the data in the speed and throttle plots. Cathy speed plots show she'll slow down for a corner, go around the corner and a steady speed then speed up again. My speed plots show very sharp peaks and valleys. Either I'm on the throttle, or I'm on the brake. Ideally what I want to do is to slow down the car (using the brakes) enough to turn in, then immediately get on the throttle and power through the corner and down the straight. In most cars getting on the power that early might be unwise, in rear wheel drive cars it may get you out of shape in a hurry, so the advice is usually not to get on the throttle until you've straightened up out of the corner. In a front wheel drive car nothing dramatic will happen, you may get even more understeer, this is where the stiff rear bar will help most. There was one time when I did managed to provoke understeer in turn 2, application of the throttle neatly countered it, it felt good. This is also where the EDLC will help most, preventing spinning a wheel in a corner. I had no wheel spin all day. This approach also shows up in the throttle data, mine was pegged at max for longer than Cathy's.

I have video of course, my best lap: http://btwyx.com/Movies/LagunaFeb14Best.mov

Cathy's best lap: http://btwyx.com/Movies/LagunaFeb14CBest.mov

This is me in the foggy first session:




There was better weather later

 

Thanks for the great writeup. I was comparing your video to a video I have with data from my first time at Laguna Seca, my best lap was 2:06 on the stock Continental run flats. I know I have to work on braking later and harder, but comparing the videos makes it really obvious. Apex speeds were pretty comparable and with the HP advantage of the S I could accelerate faster, but especially going into turn 2 I am always backing off earlier and not braking as hard as I could.

My first day at Laguna Seca I could never keep my foot down going over the hump on the main straight. It is really tough to convince yourself that even though you can't see what's over the hill, just keep the right foot planted and it will all be OK. The second track day I could :-) now I just have to carry it farther and brake harder. But it's better to creep up to the limits carefully than go past them in a hurry. Second day I got down to a consistent 2:04 and I know with some practice (and maybe better tires) I should be able to get under 2:00. Now I just have to wear out the Continentals...

 

As always, entertaining and enlightening...

But...

Could you give us a little more insight as to how the ZIIs performed. Good, bad or indifferent? or all of the above? This is a new tire on the market and there has not been much real-people track experience written about them. Just by the gs you were pulling (1+ g on the video if I read it right) they seem good in that aspect. I couldn't get that high with my old, over heat-cycled Z1s

Also, I am surprised by you saying that you thought the car was pretty neutral with the bigger bar. My experience with a 20mm solid bar, Koni FSDs, -1.6 deg front camber and the rest of the base S suspension was oversteer with a very slight lift of the throttle in a corner. In fact I could tell when the car was tripoding and it really wanted to come around. But it would push (understeer) with any applied throttle. It was too touchy for my tastes. Part of that was likely the FSDs; they never seemed happy on the track. I am liking my Sports Suspension with -1.5 front camber a lot, lot more than that setup and consider it to be pretty neutral.

Lastly - How did you like the custom shocks?

 

I was comparing my best lap (2:00.9) to my previous best in Tristan (2:01.3). I made up some time for turn 4 to 5, lost a slight bit up the hill, then made up a lot through 9 to 11. In Tristan I was trying to keep my speed up entering 4, but found I was too fast to keep my foot down. On Sunday I was braking for the entry to 4, but then managed to keep my foot down all the way to 5, so entering slow enough to keep my foot down seems to be the best strategy.

For Tristan's lap I was experimenting with an earlier entry to 9. I saw that I had space on the exit from 9, so presumed I could take an earlier entry and still keep it on the track, I was also not braking, just giving a little lift to set up for the corner. In Bertie I was taking my regular late entry and braking to set my self up. That strategy seems to be the best.

I compared my best lap to a couple of other good laps. Most of the time was actually made up between 6 and 7. I seem to have made a really good go of 6, along with nailing 2 and 5. My best lap in Tristan I obviously made an even better go of 6.

All in all, it seems to say to get a good lap, you need to nail every corner, or a suboptimal turn can ruin a good lap.

 

If you want to have a good target to aim for, there's always Randy Probst's lap: http://www.motortrend.com/features/p..._cooper_s.html He managed 1:52, probably on stock runflats. I aspire to be that good.

If you want to wear out the Contis, track days are a great way to do it. Personally I like to keep my street tires round and have a set of track tires, then you don't need to wait.

For a more realistic target in a Cooper-S, my best was a 1:53.8 http://btwyx.com/Movies/LagunaMarBest.mov Shawn did have a limited slip diff. He was doing 103 over turn 1.

If you get more power, like the JCW, I got up to 110. The problem then was finding a suitable line so I had time to brake for turn 2. http://btwyx.com/Movies/LagunaFeb13Best.mov

 

I'm not sure I make a good test driver, the car is what it is, and I'm not sure I notice many differences.

The ZIIs seemed to do alright, they seem to be on a par with the Bridgestone RE-11 tires which are my favorites, at least by the laps I was turning. I don't take much notice of the gs, but the g plot is quite impressive. It regularly touches 1.2g and there's one peak to 1.55g. I think that may be an artifact of the rumble strip at the turn 4 apex. The braking plot isn't nearly as impressive, its only peaking at a little over 0.8g. Apart from that, they didn't wear much (0.2mm on the front) and only grained a little bit on the back, which is good.

I was also surprised by the neutral handling. I don't have the camber you've managed, but I was hoping to get some corner entry oversteer, when trail braking. After turn in, I do tend to get on the power immediately, so that would counteract some oversteer. Its still missing on entry.

I can't say I noticed any difference in handling due to the dampers. I think the ride is showing an improvement in high speed bump. Ie it seems to absorb big bumps better than it used to.

 

For any Southern Californian folk (or any Bay Area folk who don't mind a drive), MINI Thunder have announced "MINI Thunder Down Under", which will be at Buttonwillow Raceway (a couple of hours North of LA on I-5). http://www.motorsportreg.com/index.c...2#.UwuPgWGYaXw

We signed up, but not many others have so far. The only downside will be its in August (23rd), when the average high is 95°F. At least there's an air conditioned building to retreat to. Buttonwillow is a fun, and safe track, though there's very little elevation change. (There's a couple of 10ft bumps at Cotton Corners and Phill Hill.)

We're also going to do a Hooked on Driving day at the newly expanded Thunderhill. If you havn't heard, Thunderhill is exanding and adding a 2 mile track to the West, called "Thunderhill West". It can be run as an entirely separate track, or you can put all the tracks together and get a 5 mile, 27 turn monster track. Hooked on Driving are promising the monster track, and we're going to try it out on 28th September.

Our next appearance on track is going to be 23rd April at Sonoma with Hooked on Driving.

 

Thanks. I am look to get a set of ZIIs as a "drive to the track and use in case of rain or I wear out my R888s" tire. I was looking for your experience just because you aren't a "test driver", just one of us trying to do well. Sounds like they will be good for my purposes.

I should have said that I have installed IE fixed camber plates which give me the -1.5 to -1.6 camber in front. The difference seems to be car dependent (the former for my current car and the latter for my previous car) which could be the size and/or location of the slot in the strut tower or other differences.

Also, your data is higher than I can achieve even with the R888s. I am also using Harry's lap timer. I wonder if there is a difference in the calibrations or I am just that much slower

 

I don't take much notice of the absolute g numbers. Harry's never seems to calibrate correctly either. I was also having a little trouble with the phone coming lose. The ZIIs would do quite well for what you want, though for track only tires, not dual use, I'd probably still get RE-11. (Not RE-11A, they don't work for us.)

I guessed you must have some camber help, I've never got more than 0.7° with the stock adjustments. Bertie could definitely use some extra camber, I was disappointed when camber plates were taken out of this years autocross rules.

 

I was wondering about Harry's calibration. However, even though the absolute values may be off a little, the day to day results seem to be consistent which, I guess, is what we really need in order to assess improvements.

I watched the rule discussion about the camber plates and, too, was disappointed as it makes a difference in tire wear if nothing else. It is a shame that you didn't get it.

Other than the camber plates, I just have the sports suspension option and the factory alignment. With the added camber the initial bite of the front tires is really nice. The car will still push if too fast or on the throttle too soon. But the car will also rotate easily with the throttle. I tend to run 39 psi up front with R888s and the one time their temp was taken the comment was "they're good". These are 225s on 7" wide wheels. I like this setup for the track. You would like these for your JCW on the track.

 

On Thursday we were at Sonoma with Hooked on Driving. The original plan was for us to both run in the B intermediate group, with me in Bertie and Cathy in Algy. With our problems with Bertie, we could't run him, so our friend (who we'd sold Tristan to) graciously agreed to let us borrow Tristan back for a couple of days. In exchange I changed the brake pads all round, which the computer was starting to bug him about even though there was some pads left. I put in Yellowstuff pads to make sure they survived on track, and then they should last about forever on the street.

Then we also had new tires for both MINIs, for which I had to find tire pressures. For Algy I really hadn't liked the Bridgestone RE-11A tires we had, so I took an excuse to get rid of them and got some Dunlop ZII in 215/40-17. These can serve as Algy's track tires, where they maybe a little short, and as back up autocross tires for Bertie, where they're about the same size as his 16" ones. The ZII tires are now discontinued, and they'd sold out of the size he regularly uses. So I got some that Algy could use on his 17" wheels which Bertie could borrow if necessary. For Bertie I'd got some Toyo R888 in 225/50-15 on the spare set of 15" (x6.5") wheels. These should work well on the track and we can use them at BMW club autocross events.

These tires are "r compound", i.e. racing tires. They're very soft and sticky, but may not work well unless they get heated. They're not slicks, they do have tread, so they can be driven on the street (cautiously). They were however surprisingly noisy. I expected R-comps to be noisy, but I wasn't prepared for the full horror of exactly how noisy they were. The tread pattern is wide cuts indispersed with wider treadblocks. I think the treadblocks slapping against the pavement is the cause of the noise, its pitched about right. Between about 10 and 40 mph the tires just howl (dropping in pitch as you slow down). The first time I drove on them I though something was wrong with the car, as some one put it, its like all four wheel bearings are going bad at once. It also reminded me of a Spitfire flying by. Swapping the wheels back for the regular tires convinced me the noise was the tires, so now I just have to live with it.

Then I had to work out what tire pressures to use. I set the ZII pressures around the same pressures as had worked with Bertie's ZII's on track, with the expectation that they'd heat up a bit and gain some pressure and I'd let some air out after a session or two if necessary. After driving them on the freeway, their pressures looked about right, maybe slightly high. I expected them to heat up a bit more on track, so I took 2psi out to start with.

For the R888 Toyo recommend a hot pressure of 32-38 psi. So I set the pressures at the lower end of that range (32.5) and expected them to heat up and need some air being let out. Driving on the street seemed to indicate that was about right for the street, but they were only about 80°F, I expected them to heat up a lot on track, so I'll need to let some air out. Toyo recommend a working temperature of 160-220°F, and I've seen 160°F on track, so they may add another 8psi as they heat up.

My previous best time in Tristan at Sonoma was a 2:13.3 on RE-11 tires. That was one of the first time I used the RE-11 and was just finding out they were much faster than the previous tires. I didn't think I had much room for improvement over that. When I was going to run Bertie on the R888 tires, I wasn't going to be able to tell how much of any improvement was tires, and how much was Bertie. Driving Tristan eliminated the variables, so I hope to improve on that time, and will blame the new tires for the improvement. I was thinking maybe 3s a lap, so if I could do around 2:10 I'd be ecstatic. The last time we were at Sonoma, we were driving Algy, I made mistakes and the tires (the RE-11A) didn't seem to work so I only managed 2:09.7. One mistake I made was to take the inside line at the hairpin (turn 11), that was a quicker way through the corner, but left you with much less exit speed. By the time you get to turn 2, the exit speed had cancelled out the time gained and added up to 1s or so lost.

Reviewing my previous best lap in Tristan, I wanted to make sure to take the late apex line around the hairpin. Though I'd take it easy with the new tires, I didn't want to over do it and end up in the tirewall. Up the hill to turn 1 has always been a problem, I was going to have to work on that, see if I could keep my foot down. I'd take the tight line around turn 5, and as always try to keep my speed up through turn 6. At turn 7 (the other hairpin) I was going to experiment with a double apex line. After the last time at Laguna, I'd finally worked out a convincing double apex line, and it seemed to help a lot. There isn't much straight following, so corner exit speed is not so important, reducing time spent in the corner is a win. I'd take the inside line around 9, and be circumspect at 10, while keeping my speed up. I'm ambivalent at 10, there's a lot of time to be made, but if you get it wrong you can end up in a concrete wall. Turn 10 is surprisingly fast, I was doing it at 78mph, so can be a disaster when it goes wrong. I had the idea that you might be able to gain time in turn 3/3a by chopping off the entrance to turn 3, much like I do at the Corkscrew at Laguna, or I experimented with at turn 5 at Thunderhill. This is what I might call an "autocross line". At autocross you have to decide whether you want to carry speed, or chop time. Sometimes one way is faster, sometimes the other.

The day was billed as "Ferraris and Friends". It was to be the prelude to the Ferrari challenge weekend at Sonoma. We'd been warned ahead of time that we couldn't use the usual paddock, that was occupied by Ferrari challenge trucks setting up. We were banished to the back paddock, and there were plenty of Ferraris around. Someone commented that the Ferrari drivers were difficult to coach as they didn't take direction well.

With the lack of paddock space, we had to grid up in the hot pit. So they couldn't do the usual thing of having several lines you choose faster or slower lines depending on how fast you were feeling. There were only two lines, for faster or slower. Were were a little hurried getting to grid, so I didn't have my rearward facing camera mounted, and I never got around to letting out the 3psi of pressure from the tires as I intended. We gridded at the tail end of the fast line, and then were delayed for 10 mins. They were clearing up an incident on track. I never did find out what happened.

That was pretty much the pattern for the day, we'd grid up at the end of the fast line, or the front of the slow line which put us in the middle we'd point a few cars by while I warmed the tires. With Toyo's recommendation for working temperature I started off using two warm up laps before starting to push things. Later on I got more confident and started pushing sooner. For the first lap or so I'd see Cathy in the mirror and I'd be wondering if I needed to point her by, then she'd point someone else by and I'd lose sight of her. The new tires accentuated the contrast between corners and straights, as I was probably in the lowest horsepower car most other cars could catch me easily on the straights. However in the corners I usually have an advantage which balances out to me being about mid pack in terms of speed. This time I'd leave other cars in the dust through 3 and 4, and around 6. So if a car was catching up to me at turn 2 or turn 6, they wouldn't be in a position to overtake by the time we got to the passing zones around 5 or 6-7.

I was also surprisingly faster than a lot of cars around 9. I was exiting 8a almost hitting the limiter, shifting up to 4th down the hill, and then took the inside line around 9 with my foot flat on the floor. It made turn 9 the fastest place on the track, the speedo was indicating 95mph or so, though the data says it was only 90. I was being careful on my entry to turn 10, after my "moment of appreciation of mortality" I had at a previous Sonoma day, where I had a bobble in turn 9. I suddenly realized I was doing 95mph, heading directly for a concrete wall, and almost losing control. If I don't manage to get around turn 10, it would be a big disaster. My line at 10 was also a bit weird, having taken the inside line around 9, I wasn't pointing in the usual direction to brake and take a wide entry, so I point directly across the track at the apex of 10 and brake, my turn in point is roughly the apex of 10. That makes the entry to 10 rather faster than the average car, who have already done their braking on the other side of the track before turning in. All in all it meant I caught up with a lot of cars in 9/10, some quite surprisingly quickly, which persuaded some of them to point me by on the way to 11, which was a passing zone for us.

With this disparity in speeds of straights vs corners, I was held up by some cars who were reluctant to point me by, and I may have held up other cars who may have been faster overall, but were never close enough in a passing zone. Several times I pointed one car by, only to be badly held up by it on the following laps before I could persuade them let me past again. All in all, I didn't get much clear track.

We also had downloads after most sessions, which gave me some ideas for different lines. For the third session the group leader also went out with a camera car, and after the 4th session we studied the video and saw the lines and mistakes people were making.

In the first session, I was very cautious getting used to the new tires. I couldn't work out how to do the double apex at 7 line I was planning, the entry is blind. 7 is actually over the brow of a hill, which means you can't see the apex as you enter the braking zone. I had planned to try like I did at Lagna which is aim at the apex and brake while crossing the track. My best lap for the session was a 2:17, which seemed like a good start. In the download, there was discussion of the double apex which persuaded me to try again. This time I braked in the usual way over to the left, maybe a little earlier, then at turn in head for the first apex. I couldn't say it was better, I did notice I was using more track on exit, so it was definitely a slower exit from 7. This was confirmed later in the video download, where I did a "perfect" single apex in front of the camera car which did a double apex. It caught up to me a lot, but at the second apex we were traveling at totally different angles. I went back to the single apex in the third session for comparison. The data seemed to show that the double apex was 0.4s faster overall. Even without the data, the single apex felt a lot slower, so I had difficultly persuading myself to carry on with it and my line was drifting back towards the double apex. I used the double apex for the rest of the day, I beaked more angled towards the apex, and trail braked to the apex. I caught up to a lot of cars using that line.

Throughout the day I was taking tire temperatures to try to work out the correct working pressures. For my tires they indicated they were over inflated for the first two sessions, I was expecting that for the first session as I hadn't let the air out I was planning too. I let more air out of the fronts for the next two sessions. After the 3rd session I came off the track hot (without a cool down lap) to try to get an idea of the hot temperatures. They were showing 140-150 up front and 120-130 at the rear. They may have been approaching Toyo's recommendation of 160+°F. After the 4th session they indicated the pressure was too low, so I intended to pump the tires up a bit, but the video download took all the tire, so I didn't get to do that, so they were also under inflated for the 5th session. Cathy's tires were also indicating slight overinflation so I let a psi out all round after the first and then 1 psi out of the fronts before all the following sessions. I think they were about right by the end of the day. One complication is if you let air out of the tire, it will tend to heat up more, which will increase the pressure. After the last couple of sessions I measured the pressures as quickly as possible to get an idea of the hot pressures the tires like. The Toyo's seemed to like around 37psi. The ZII seemed to like similar pressures, which is a lot less than our other ZII tires.

Out on track, my lap times peaked in the third session. I got a 2:11.2, which was pleasing 2.1s faster than my previous best. I put the improvement down to the tires. I was using the single apex in that session, so I expected to be able to go faster in subsequent sessions, but only managed 2:13's and 2:14's. I thought I was going fast, but the lap times showed otherwise. Those two session were the ones where the tires were under inflated, so I wondered if that were the problem. But its a rather dramatic effect from half a PSI of pressure. Looking at the data it says to me that I was doing much the same as I had previously, but the tires had just lost some grip. The cornering g graphs look almost identical, the faster laps just peak at higher values. In the latter session I was also trying to keep the tires quiet. One of the other helpful notes from Toyo was about graining. If you don't get the tires hot enough, you'll slide too much which promotes gaining, which causes the tires to lose grip and just make the problem worse. I had the theory that when the tire was squealing it was in its unhappy phase, so if I avoided squeal the tires should work better. I may have been wrong about that. All day I was keeping an eye on both sets of tires and they both only showed minimal graining, certainly better than any other tire we've run.

I tried the experiment with 3/3a, chopping off the entry to 3. It didn't work. As 3-3a is steeply uphill I just lost all momentum and struggled to get around 3a. I only tried it a couple of times and I was pretty sure that it wasn't working. Later the data showed that it indeed didn't work. I was slower overall and exited 3a slower. Maybe if I'd tried a more aggressive entry to 3 it might have worked, but I didn't try

The run up the hill to turn 2 was working for the most part. I managed to keep my foot down more. I didn't need to brake much for 2, and I was doing it while at a bit of an awkward angle and maybe not in a straight line. A few times I flubbed it and was way off at turn two. If you jut accept you've blown 2, you have plenty of space to get back into shape, and carry on slowly, but the car behind you catches up. I did that after my fast lap, I'd just overtaken a Ferrari and was trying to put some space between us. I flubbed 2 and he caught up, and I let him by at the next opportunity.

I was trying to keep my speed up through 6, I'm not sure I was managing it, the speed was indicating 60-64 (with the short tires, its not clear exactly what the speed was in reality.) Though for my fast lap it shows I’m sustaining 1g+ for over 5 seconds, that’s pretty dramatic. It certainly seemed faster than other cars. Sometimes I’d catch up to one on entry to turn 6, my line would put me right in their door mirror, and I could stick with them all the way around. Or if a car caught up to me by the entry to 6, it was usually no where to be seen by the time I exited. At one of the downloads turn 6 was discussed and the classic entry is over to the right, and then smooth out the turn drifting to the left. I'd been entering on the left, about a car's width from the inside and keeping that distance until you head for the apex. So for the last session I tried the wide entry, looking at the data its unclear which worked better, the left entry may be 0.1s better.

In the video download we saw various cars and lines. Gordon had got in line a few cars behind us. He passed a couple on his outlap and caught Cathy at turn 11, she pointed him by on the exit from 11. Then as he's rounding turn 1, you can see me at turn 2 with two cars just caught up to me. I'd just completed my first warm up lap at the time and was still wanting another warm up lap. You can see me through 3/3a and 4, then at 5 I'm busy pointing by the two cars behind me, and I didn't notice I dropped a wheel off the apex of 5. There's no berm at the apex of 5, which has always seemed like an oversight to me with the lines I take, so I threw up a cloud of dust. I'd spoken to Gordon earlier and he said he was going to make a joke about me trying to persuade him to back off, which he did. I'm surprised that I didn't notice at the time.

One of the cars took the point by, which only left a Bimmer I was expecting to point by at the exit of 6, but the bmmer pointed Gordon by, so Gordon caught up with me as we entered 7. Thats when I did my "perfect" single apex and Gordon did the double. My line through the Esses was pretty good, but my entry to 8 caused some comment. I deliberately aim at the apex of 8 and brake on the way there. This was interpreted as me making a correction. Similar discussion ensued for turn 10. I pointed him by at the exit of 11, having left him a little behind at 9/10.

Cathy did well. Her previous best was 2:16.9 in Algy at the previous Sonoma day last year. In her first session she managed 2:19's, a very good start. Her second session wasn't so good, she caught a lot of traffic, most of it caused by a Dark Silver MINI, which was not managing traffic well, and didn't seem to believe in point bys. Cathy trailed it for two whole laps and never got a point by. Most other laps it was the cause of long trains of cars. In this situation Cathy will always point someone behind her by, which slow down her passing someone. However in her third session she managed several 2:15, including a 2:15.0, looking at the video it was actually a 2:14.8. her final sessions weren't that fast, but did manage several 2:16's and 2:17's in the fourth session.

Looking at the video her fast laps were when she got clear track, the slow laps was either passing something, or being passed. Also at the beginning of most sessions she got behind me. I did wonder if I should point her by, and on one occasion did, but she was pointing someone else by at the time. She said she knew she was slower than me so was content to just try to keep up and observe my lines.

All in all it was a good day. I'm pleased with the 2:11, but think that's just tires, not me. I'm puzzled at the drop off in the last two sessions. Reviewing the video, it may be that I was faster when pursuing other cars, or trying to keep ahead of them. The fast lap was when I was trying to keep in front of the Ferrari (and then flubbed 2). I have some tire pressure data which should help me setup the tires for when we want to autocross them. I'm wondering how good the R888s are going to be at autocross as the tires never get very hot. Tristan is still in one piece, so we can give him back to our very gracious friend. I texted him to say Tristan had survived.

I have video of course, me just having passed the Ferrari and trying to keep ahwad of him, ending up with flubbing turn 2: http://btwyx.com/Movies/SonomaApr14Best.mov

Cathy's best lap, when she got clear track: http://btwyx.com/Movies/SonomaApr14CBest.mov


Us at the beginning of session 1:




Me at 3a:




Cathy exiting turn 11:

 

Nice, always a fun read and I enjoyed your video.

 

I made a video of one of the laps when Cathy was following me closely. Its not one of my fastest laps, but it is one of Cathy's fastest, as she was trying to keep up. http://btwyx.com/Movies/SonomaApr14B&C.mov

The handy track map might help here:




I also did a comparison of my previous best lap vs my best lap on Thursday. The improvement was not just the tires, the tires didn't seem to make much of a difference. On Thursday:

I did an earlier turn in at turn 2, so made an earlier apex. This lost about half a second by the time I got to turn 3. (-0.5)

Taking turn 3 with less braking, which I was noticing at the time, was worth about a 1.25s improvement. This I was thinking was the tires. (+.6s)

Turns 4/5/6and up to 7 were about the same, maybe 2-3 tenths better overall. The new tires didn't seem to be helping in turn 6. (+.75s)

I gained half a second in turn 7. I was surprised that I did a double apex last time, but this time I turned towards the apex before braking, and then trail braked into the turn. Chopping the entry like that was mainly where the time was made. (+1.5s)

I made up three-quarters of a second by braking later into turn 8. I'm not sure why I braked so early last time. (+2.1s)

There was a small gain to the entry of 10, but then I lost 0.3s getting around 10. That's being circumspect about 10. (+1.9s)

The I gained 0.4 round 11 and to start finish. It looks like I took an ealier apex at 11, so got their faster, but was going slower past start finish. (+2.2s)

 

You're getting good with the video. That is an interesting perspective to have the 2 cars in 3 windows.

You obviously have dug into this much more than anyone can see in the videos, but I am really surprised about the lack of difference you are seeing between the RE-11s and the R888s. The R888 are a stickier tire plus, for the same size, they have about 0.4" wider tread. All things that should make them faster. For me they were a big change from the Z1s I had and I thought the Z1s and RE-11s were similar in performance by the TireRack tests. But some of my difference might have been the tire size; the R888s are 225-45s vs 215-45s, both on 17" wheels. I aim for about 39 psi hot on the R888, starting from 32 psi up front.

 

Here's a video of my R53 at Ridge Motorsports Park up here in Washington State:
(One lap, in car video with telemetry, 1080p