This was at Portland International Raceway in Portland, OR.

Approximately 45 degrees outside, 1/2 tank of 92 octane E10 gas, no lightening of the car, front tire pressure dropped to 26psi (not that it helped anything as it was too cold for summer tires). I did spray the intercooler with water between runs.

60' not recorded on this run, but was in the 2.4's all night...
1/8 9.612@78.59mph
1/4 14.605@99.08mph

Last year when I was stock I ran 15.308 @ 91.34, then earlier this year with a 15% pulley and HAI a 14.747 @ 96.14. Tonight was my first time out with my RMW cam, RMW street header and RMW tune. The funny thing was the 1/8 was quicker (just barely) with just the pulley and HAI as I didn't have the second gear traction problems I had tonight.

Overall, I'm disappointed by only picking up 2.31 mph in the quarter mile with $2500 in mods/labor as I got almost 5 mph for about $300 last round. However, I couldn't hook up in first or second gear, so maybe my mph would be faster as well if I could put the power down, but I'm mostly used to seeing that affect ET, but again, I've never had wheelspin like that before!

What's the verdict, ask Jan where my power went or did it go up in tire smoke?

-AndyW

 

Well, since I wasn't there, and haven't driven your car, I cannot say for sure. But, you know some of it at least went up in heat and rubber smoke, so I would at least wait until you got a good run on grippy tires before I started wondering what went wrong. At this point, it seems like you've answered that question yourself.

 

Andy do you know what the car weighs with you in it?

Try and put your times in a speadsheet like I attached on the UK BMW Show thread, this will help you show where you're gaining loosing ET.

What was the temps the other times you were at the drags ?

Good mph

 

I don't know what the car weighs, but it is an S with no options other than stripes and fog lamps, so it is about as light as you can get without removing bits and I have 11 lb 16" SSR Competition wheels, so they are not the problem . I weigh 155 lbs too, so nothing to talk about there either...

It was 55 degrees my last time out and I think that 45 degrees is just too cold for these tires. It was also 45 degrees this morning on the way in to work and I did a little experiment where I went full throttle in second gear at 2500 RPM and then waited for the car to lose traction, which it did at 3500 RPM. Looking at my dyno chart, I am putting 120 hp to the wheels at 3500 RPM, so that is apparently the grip limit of these tires with this car in 2nd gear at that temperature. Not real impressive.

I will run again in the spring when it is warmer and see what we can get.

-AndyW

 

You need better tires man, that's where your time went........

 

Andy, please see attached spreadsheet, the first setof figures are calculated Flywheel Horsepower figures, the second set taking a wild guess that you in fact weigh 2700lbs and working 214.5 as your Hub / wheel horsepower figure you can see the gains you have made.

MPH = Horsepower

ET = How efficent you transfer the horsepower to the ground.

Save it and have fun with it

 

You wouldn't get a higher MPH from hooking up in 1st, most likely a lower MPH but a lower ET as well. 2.4 second 60 foot is pretty bad, I could pull 2.1's back in the day with my turbo civic on H rated firestones. Lower the front pressures lower to say around 22-23 PSI, jack up the rears to 40 and work on feathering the clutch out of the hole. With a 2.1 your car would be close to the 13's with a 99 mph trap.

 

Different days, different conditions.
It's possible everyone was "off" that night, or that everyone had a fast night earlier in the year?

Similar temps? Similar humidity levels? Has the track been resurfaced/etc?

 

I finally got back to the track in a little warmer weather (62 degrees) to test whether my massive wheelspin in first and second affected MPH or not. It doesn't.

Here's my best run now with a little more traction:
60': 2.383
1/8: 9.364
MPH: 78.87
1/4: 14.346
MPH: 98.84

I raced side by side with a stock Mazdaspeed3 for reference. His run:
60': 2.448
1/8: 9.422
MPH: 80.26
1/4: 14.287
MPH: 101.16

A few lessons from this thread:
1. Wheelspin, even massive multi-gear wheelspin doesn't seem to affect MPH.
2. Summer tires are nearly useless below 50 degrees.
3. The bang for the buck champion is the 15% pulley. +28hp for under $500 installed. I only got +18hp for the next $2500 (cam/header/tune), but it does have a much broader torque curve which is nice on the daily commute.
4. If you're thinking cam/header/tune, get the head too.

-AndyW