How to do 12's in the QM (long) - The Unofficial BMW M5 Messageboard (m5board.com)

ELEVENS · 6th March 2004, 15:46

It's getting to be race season again for many of us, and I've been getting a few pm's about running the 1/4 mile, so here's some things that worked for me. Most is what I've learned is from running maybe a thousand 1/4 miles over the years, but realize that this is only my opinion, and what works for me may not work for you. Some of the key M5 points were learned from board member "bluemax", a professional drag racer and THE KING of M5 1/4 mile, running mid-12's with his beast.

1) Plan your race trip so that you are racing with air temperatures between 50 and 70F. Winds need to be calm, or better yet, a strong tail wind! Low humidity, and the higher the atmospheric pressure, the better. Plan your fuel so that you have about 1/3 of a tank of premium fuel when you arrive at the track. Fuel weighs 6 pounds per gallon, and you don't want too much, or worse - too little, when racing.

2) When you get to the track, open the hood and let the motor cool. Heat soak resulting in increased charge temperatures is not your friend at the track.

3) Now gut the car. Remove floor mats, cel phones, owners manuals, radar detectors, all tools, M-Mobility, umbrellas, etc. You will be surprised how much all this stuff weighs.

4) Tire pressure: Max out the air pressure in the front tires - 50. 32 worked best for me in the rears.

5) Before your run, make sure all unnecessary electrical systems are OFF. DSC OFF! SPORT ON! Don?t bother with a big smoky burnout in the water box. With stock tires, I drive around the water box and do a quick dry burnout to clean the tires.

6) Ignore the guy in the other lane - your opponent is the clock. Carefully examine the launch area. Many times the best traction isn't where everyone else is launching, but slightly off-center. Shallow stage. This means slowly and carefully pull up to the start until the first yellow staging light illuminates, then stop as soon as the second yellow staging light illuminates, and no deeper. Shallow-staging allows for more rollout before tripping the timing equipment. This means your car is already rolling (head start) before starting the clock. You will lose some consistency in your run-to-run times by shallow-staging, but if your goal is 12 seconds, this is the thing to do.

7) Make sure your car is pointed absolutely straight down the track and remains perfectly straight all of the way. Even a slight wandering or correction will kill your time.

8) I tried 1500-2000 rpm launches, and 2000 worked the best. Do not move the gas pedal until the tires hook up. The natural tendency is to FLOOR IT when the green light shines. DON'T DO IT! My car wheel-hops so badly under full power, you would think the whole back end will fall off. That's if you don't kill your clutch first. Wait until the tires hook. With some practice, you can actually feel the suspension "load up" -the weight shifting to the drive wheels. That's when you floor it. This will also preserve your delicate clutch.

9) The tachometer is slow and can't keep up with the quick-revving S62 motor, especially in first and second gear. You certainly don't want to hit the rev limiter, so shift at an indicated 6500rpm. In third and fourth you can run it out a little more, maybe 6700. You must change gears without letting up on the gas pedal, and shift mercilessly as hard and as fast as you possibly can. Just as a test, I quick-shifted fourth gear letting up on the gas, and it cost about a tenth of a second!

10) Just remember to keep the car pointed straight, and STAND on the go-pedal all of the way through the finish line.

11) Be persistent, and expect your first runs to be high 13's. Take 4-8 runs. You will need to adjust the tire pressure in the rears before each run. Now shut down the car (with the hood up!) and go watch the other guys race for an hour or two. Your cooled-down car will run much better. Now run again. This is the one that counts. If everything goes well, you will collect your 12-second time slip from the timing booth!

Greco · 6th March 2004, 17:49

Awesome Bill. Thanks for tips. I'll be sure to try this technique before I sell the 540.

M5 ENG · 6th March 2004, 18:29

Do you have any trick to keep from hitting 5th instead of 3rd? I'm so used to a 4 speed that a lot of times I feel that I take too much time making sure to hit 3rd.

Rick

Terk · 6th March 2004, 19:06

Thanks for all the info Bill, very cool stuff.

For some reason, keeping your right foot planted on the loud pedal while ripping through the gears seems criminal in such a beautiful car

.... of course I had no problem practicing that technique in a Dodge Daytona Turbo Z many moons ago.

I look forward to hearing about your results this spring after installing all those mods.

Regards,

T

CSBM5 · 6th March 2004, 21:44

Thanks Bill for the great tips. Just curious...if you do a full-throttle power shift on 1-2, don't you end up with a good bit of wheelspin in 2nd?

As much as I want to take the M5 to driving events (like today's at VIR) and to the strip, I think the hot ticket is to have TWO M5's

One to mod and drive hard at the track(s), and one to drive everyday

MIB · 7th March 2004, 00:40

Hey Bill,

Excellent.

I always shallow stage.

My best time still is 13.3 in rediculous heat and weather conditions.

It should start to cool off from here, and then more runs. I haven't run with the new Tubi-Powerchip as yet, or with the AA CAI.

I granny shift. I cannot bring myself to leave my foot on the accelarater when shifting. I just can't do it.

Also, I leave everything in. Radr detectors, umbrellas, M mobility. Everything as if we were going to dinner. Even the glove compartment is full, and sometimes, the gas tank is full.

I just drive to the Track as is, and run. So 13.3 isn't bad.

ELEVENS · 7th March 2004, 14:36

M5 ENG: I've never mis-shifted from second to fifth with my car. Do you have a short shifter kit? I have installed one, but actually liked the stock shifter for dragging.

Terk: The track is the only place I powershift. But you're right - the first time I felt really guilty. But it was so exciting it quickly became "worth it".

CSBM5: Oh yea- the full power 1-2 shift really lights up the tires! You don't need two M5's though - just choose your mods carefully as not to compromise the M5's balance of luxury and sport.

MIB: It's just too hot where you race to rip off a smokin' time! Did you ever put a SSK in Yoda? You really should try some power shifting :p After the initial "violation", you'll be "over it" and your times will drop several tenths.

M5 ENG · 7th March 2004, 17:24

Quote:

Originally Posted by ELEVENS

M5 ENG: I've never mis-shifted from second to fifth with my car. Do you have a short shifter kit? I have installed one, but actually liked the stock shifter for dragging.

Terk: The track is the only place I powershift. But you're right - the first time I felt really guilty. But it was so exciting it quickly became "worth it".

CSBM5: Oh yea- the full power 1-2 shift really lights up the tires! You don't need two M5's though - just choose your mods carefully as not to compromise the M5's balance of luxury and sport.

MIB: It's just too hot where you race to rip off a smokin' time! Did you ever put a SSK in Yoda? You really should try some power shifting :p After the initial "violation", you'll be "over it" and your times will drop several tenths.

No short shifter kit. I just have to practice moving the lever up and not so much pressure to the right in the 2-3 shift.

gsfent · 7th March 2004, 23:34

Quote:

Originally Posted by M5 ENG

No short shifter kit. I just have to practice moving the lever up and not so much pressure to the right in the 2-3 shift.

M5 ENG
Try shifting 2-3 using the heel of your hand. If you push up (forward) and at the same time -slightly- to the right (like opening the face of your golf club), the spring loading should keep you in the 3-4 gate, and you shouldn't hit 1st or 5th. I find to hit 5th from 2nd, I have to deliberately move the shifter over. I am using a SSK.
Regards,
Jerry

MIB · 8th March 2004, 00:42

Quote:

Originally Posted by ELEVENS

MIB: It's just too hot where you race to rip off a smokin' time! Did you ever put a SSK in Yoda? You really should try some power shifting :p After the initial "violation", you'll be "over it" and your times will drop several tenths.

Hey Bill,

Yep, I bought a Rogue Engineering SSK & WSR for my Carbon Black Beast, but never fitted it. It went in Yoda the second day I had him. I since fitted the mounts.

I will have to wait until winter foir some smoking times. We do get down to single figures celius in Winter.