Launch Tips for Drag Racing- 1/4 mile

[Greg S]

I went out to the track again, but wasn't expecting to do well since my clutch is almost gone. You know it's going bad when you don't chirp anymore, and the revs stay the same going into 2nd and 3rd gear then slowly drop back down. Funny thing is I still managed to pull off a 14.4 @95mph with a 60' of 2.0. My off the line was great but once I got rolling, my gears wouldn't grip; the RPM's wouldn't go down. And what pisses me off is the minute I get off the track, the clutch doesn't slip anymore If you were in the passenger seat you'd think the car was a 20 second car, it's very deceiving with this clutch. I just managed to pull off a decent 1/4 time because of my 60'. But anyway the next time I go to the track I'll have a Kevlar clutch and lightweight flywheel.

Isnt kevlar bad for drag racing?

[rsagona1]

Isnt kevlar bad for drag racing?

I don't know, my friend has one in his Turbo GSR seems to holding for now.

[paulj1219]

Hi Dave
I Drag Race With A E30 325is.
Presently I Have On 14" Wheels
And K&n Filter & Semi Free Flow Exhaust
Can You Give Some Tips For My Next Race And What Mods I Can Do To Improve To Power Of The Car.

Thanks In Advance
Paul.

[Greg S]

It wasnt that it wouldnt hold it, it was that if you burned/glazed it the clutch was permanently ruined. Im not shure if that applies to kevlar, carbon, or both...

[SilverStreak]

You can glaze any clutch... and while the launch technique discussed here is good for times and bad for clutches, you don't sit there for 10 seconds revving it out wearing it. Once you get the feel for it and practice, it all happens pretty quick...

[SilverStreak]

Hi Dave
I Drag Race With A E30 325is.
Presently I Have On 14" Wheels
And K&n Filter & Semi Free Flow Exhaust
Can You Give Some Tips For My Next Race And What Mods I Can Do To Improve To Power Of The Car.

Thanks In Advance
Paul.

Many of the tips on are pages previous in this post, lowering the psi in the rear tires, pumping up the fronts, etc. Go back and read thru this one, many different questions addressed, etc.

As far as mods for more power, that's all a matter of your budget and your ultimate goal for your car. Peruse the E30 model forum here for ideas... or slam your wallet shut and dare to read the forced induction forum here... but I'm not responsible for your bank account's balance...

[Greg S]

You can glaze any clutch... and while the launch technique discussed here is good for times and bad for clutches, you don't sit there for 10 seconds revving it out wearing it. Once you get the feel for it and practice, it all happens pretty quick...

I know that. What I said it that once I think carbon kevlar clutches are glazed they are ruined which makes them bad for drag racing.....I think.

[JBgotM]

What could be possible sources or lower trap speed (i.e. losing power) at the strip from one night to another?

I ran 101-102mph a coupe weeks ago and thought i should have been a little higher than that, then last night I was run 97-98 which was aweful.

There was an E46 M3 only running 99-100 when he saiid he normal runs 104.

Weather can be a factor, then if something is wrong with the car you can be down on power, but what are some of the other factors that could affect traps?

If I know what is causing it, I can try to account for it or at lest learn.

TIA

[SilverStreak]

air density, which is comprised of temps, humidity, and elevation.

i would lose 2-3 mph in my traps on my Z3 from 117 mph to 114 mph at the same track, but a 40 degree temp difference, and about 50% more humidity...

if all cars are getting lousy traps at the track on the same night, it's usually air density related. if it's just your car, could be a million things, from gas to god knows what...

[Dark Helmet]

If its only your car sucking, I would typically chalk it up to operator error.

viva la weight transfer!

[paulj1219]

Hey does the weight in the car make any difference?

Paul

[Dark Helmet]

yeah, lots.

[SilverStreak]

Unsprung weight can kill ya. General rule of thumb with passenger cars weighing around 3000-4000 lbs is 100 lbs can cost you 1 tenth. And weight in the wrong place (front or rear, depending on FWD or RWD) can hurt you at launch...


LOL at das... operator error...

[paulj1219]

Hey I Have A Rwd
Where Do I Need The Weight The Most?

Thanks
Paul.

[SilverStreak]

I don't mean to give you a short answer, but it depends on the exact car, the suspension set up, the weight involved, launch characteristics, etc...

Generally speaking RWD cars with close to even weight distribution do pretty well, cars that are real light in the back and have lots of low end torque can get squirrelly at launch if traction is limited...

[paulj1219]

hey i want to put a chip in my e30 325is
what would the chip do for me on the 1/4 mile
and what chip do u reccommed.

[SilverStreak]

hey i want to put a chip in my e30 325is
what would the chip do for me on the 1/4 mile
and what chip do u reccommed.

You'd be better off asking the E30 guys for advice on that... and agian, not to give you a short answer, it really depends on the exact car, chip, and corresponding mods, etc...

[BETO]

Regarding tyres.
If you have to choose between R-comp Advan on SSR comps and street Michelin Pilots on oem wheels for the rear, wich one would you choose?
With GC coilover and Konis yellow, you go soft all corners? Front is heavier than rear.

[MrBlonde]

Regarding tyres.
If you have to choose between R-comp Advan on SSR comps and street Michelin Pilots on oem wheels for the rear, wich one would you choose?
With GC coilover and Konis yellow, you go soft all corners? Front is heavier than rear.

The R Comps will give slightly better traction.

With your shocks you want 90/10 on the fronts and something like 50/50 at the rear.

[bmr330ci]

i turn off traction controls, rev up to 3.5-4K and still cant get a chirp. what am i doing wrong? thanks

[lpgautogas]

Nice post...Thank you very much!!......

[95s52]

Awesome bump!! Way to use that search feature!!!