Tire pressure at the drag strip

[S4audi15]

Do any of you guys lower your tire pressure at the track? If so, what psi do you lower it to? I went 13.3 @104 stock on a 90 degree day. Should be around 50 degrees when I go to the track on Friday and now I have a powerhaus tune, pulley, and intake. Looking forward to see what I run. I'll keep you guys posted.


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[SpltsecondS4]

with the mods you described...id say no. i drop a couple pounds off the back of my M3...but im probably double your WHP. you can test it out, but id doubt you seen any changes to your 60ft times. my experaince with the S4 is far less at the track, but i havent really seen a need to use this technique to get a bit of extra grip.

try it though and let us know.

[S4audi15]

with the mods you described...id say no. i drop a couple pounds off the back of my M3...but im probably double your WHP. you can test it out, but id doubt you seen any changes to your 60ft times. my experaince with the S4 is far less at the track, but i havent really seen a need to use this technique to get a bit of extra grip.

try it though and let us know.

Ok ya I'll test it out both ways and let you guys know.


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[DGVR6]

launch control is different from manual but I'll let you know how I work with tire pressure.
I try to go in with high psi (39) all around, let the tires spin a bit for about 2 runs to get prep transfer and then drop until I find the right pressure. I keep the fronts a bit higher than rear. I cut a 1.75 iirc with 37 front 34 rear on conti dws.

Its much easier on the drivetrain to spin wheels than to bog around. Once you have prep transfer you should be good to go with a slighter lower pressure, I just wouldn't over do it.

[Loe]

It really depends on the track, environmental factors, tires etc etc...

I cut a 1.65 with running 39/38 psi on OEM Dunlops. However, if I drop the tire pressure below that, I get too much wheelspin and my 60ft's get worse. Other's have better luck with 32psi all around; just to give you an idea of how it varies from track to track.

[S4audi15]

Hmm I know every track is prepped differently. Sounds like the only way to test it out is one run with the normal tire pressure at around 40 and then drop it down a little for next run. I have the stock Conti dw's with not much tread which obv won't help with the 60 ft.. I'll test again when I get new tires in like 1-2 months


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[jran76]

I think what you'll find, and as indicated here, is that it really depends on too many factors to get one solid answer on this. With good track prep and conditions (warmer weather), I can run near stock tire pressures. With poor prep or cooler conditions, I can easily have to go down to 28-32 psi, or even lower.

When andthen made is record 11.4 pass, I think he was in the low to mid-20's. Primetime, who in general has the best 60' times, ran 32F/28R when he cut is 1.577 60', but he has gone down as low as high teens/low 20's when it was cold out with limited traction. Primetime recommends starting at 40F/36R in decent conditions, and lowering from there. If it's cold out, or traction is limited, start lower.....

[S4audi15]

I think what you'll find, and as indicated here, is that it really depends on too many factors to get one solid answer on this. With good track prep and conditions (warmer weather), I can run near stock tire pressures. With poor prep or cooler conditions, I can easily have to go down to 28-32 psi, or even lower.

When andthen made is record 11.4 pass, I think he was in the low to mid-20's. Primetime, who in general has the best 60' times, ran 32F/28R when he cut is 1.577 60', but he has gone down as low as high teens/low 20's when it was cold out with limited traction. Primetime recommends starting at 40F/36R in decent conditions, and lowering from there. If it's cold out, or traction is limited, start lower.....

Thank you for the advice. Will try.


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[jran76]

I should add.... My normal starting point is usually in 36F/32R, but I always run at night with so-so prep. I think sun on the track helps up to a certain point.

Last week in 55F weather (400-800 DA), I was running around 32F/28R, and cut my best 60' time (1.69).

[S4audi15]

Update: first run was the best I had 40 psi in front and 36 in the back and cut a 1.799 60 ft which led to a 12.35 @111 pass. Next pass after letting car cool off I had 34-35 in front tires and 30 in the back tires and only cut a 1.82 and ran a 12.4 @109 on the oem continental tires with little tread left. Track prep probably wasn't the best. Interested to see if I could get my 60 foot into the 1.6s with new tires, should be good for a 12.0-12.1 pass maybe.


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[Loe]

Update: first run was the best I had 40 psi in front and 36 in the back and cut a 1.799 60 ft which led to a 12.35 @111 pass. Next pass after letting car cool off I had 34-35 in front tires and 30 in the back tires and only cut a 1.82 and ran a 12.4 @109 on the oem continental tires with little tread left. Track prep probably wasn't the best. Interested to see if I could get my 60 foot into the 1.6s with new tires, should be good for a 12.0-12.1 pass maybe.


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Based on your 60ft's, you'll need approx a mid 1.7 60ft (like a 1.74 - 1.76) to run those 12.0-12.1 times. Good results nonetheless!