Air Pressure Front & Rear

[cal]

Good Morning All.
Bringing Back this form.
OK here goes question # 2 & 3 & 4

What is your Slick Preference, and Why?

Front tire air pressure, What effect does raising & Lowering the air pressure in your front tire have on reaction Time & 60 ft time if any?

I realize all cars are different, and Hoosier, MT & Good Year will all Vary some.
What is a good Starting point for tire pressure?
How High can you go before tire spin starts in most cases?

Any other info you care to share on Tires & Pressure?

Just a 1st rd Duck looking for a win.
Cal SST 1177

[Tom Goldman]

Well Cal ,this stuff is pretty much scienced out and pretty out in the open .
Bumping front pressure up or down can change RT'S a few thousandth's on fast cars , but the slower the car and bigger the tire ,usually the bigger the change is. ….But a hundredth in RT is usually about it, at least in my experience with .90 cars with small tires.
Bumping front pressure up will slightly lower the RT ,BUT ,60' should increase by nearly an equal amount.
I would never recommend going above 45# on our cars with small front tires ,the foot print just gets too small and the car gets "darty" down track.
Stockers blow them way up ,sometimes 50-55 # for heads up or record runs because it lowers the rolling resistance .
Rear tire pressure ,everybody's favorite subject , not so cut and dried . some run ridiculously low pressures and plant the rim into the ground so hard the sidewalls are shot in 20-30 runs.
Rule of thumb I've always followed is the smaller the tire is the more pressure it requires ,Larger tires ,less pressure. ….more weight ,more pressure.
You can have a car that murders the tree at 6# pressure but is inconsistent in 60' . ….Take the pressure to 7 1/2 -8# and the 60' is deadly but RT's fell off a bit.
I've run my 16x33 Hoosiers as high as 8 1/2# at 2250# in the car and they didn't spin.
Then you can adjust the shocks and start all over again !!!

[cal]

Originally Posted by Tom Goldman

Well Cal ,this stuff is pretty much scienced out and pretty out in the open .
Bumping front pressure up or down can change RT'S a few thousandth's on fast cars , but the slower the car and bigger the tire ,usually the bigger the change is. ….But a hundredth in RT is usually about it, at least in my experience with .90 cars with small tires.
Bumping front pressure up will slightly lower the RT ,BUT ,60' should increase by nearly an equal amount.
I would never recommend going above 45# on our cars with small front tires ,the foot print just gets too small and the car gets "darty" down track.
Stockers blow them way up ,sometimes 50-55 # for heads up or record runs because it lowers the rolling resistance .
Rear tire pressure ,everybody's favorite subject , not so cut and dried . some run ridiculously low pressures and plant the rim into the ground so hard the sidewalls are shot in 20-30 runs.
Rule of thumb I've always followed is the smaller the tire is the more pressure it requires ,Larger tires ,less pressure. ….more weight ,more pressure.
You can have a car that murders the tree at 6# pressure but is inconsistent in 60' . ….Take the pressure to 7 1/2 -8# and the 60' is deadly but RT's fell off a bit.
I've run my 16x33 Hoosiers as high as 8 1/2# at 2250# in the car and they didn't spin.
Then you can adjust the shocks and start all over again !!!

Thanks Tom.
Just trying to get some guys talking on here again.
Let the info flow per say.

Come on guys spread the info, even if it is basic stuff to you.
It may help a newbie somewhere down the road.

Just a 1st rd duck looking for a win.
Cal SST 1177

[Superstreet29]

My 33x16x15s like 10 lbs, even 11lbs at 2820 in S/st. Otherwise I just wad the tire then it flexes back on the stop.

[Shake & Bake]

Cal,
I run 8-lbs in my 33.5 x 17.0 x 16 Goodyear's. Any less than that and the inside sidewall wants to roll under the wheel.

[Maverick]

So, my question is, in less ideal conditions where it is 85 degrees out and the sun in on the track, what do you do to make sure you don't slip the tire? Or does you car always hook since you throttle stop it at the line?

[Superstreet29]

That’s when you gotta adjust shocks

[Maverick]

Just amazed that no one changes there tire pressure, when the track get hot. Always run the same pressure. I definetly don't know, but I run a smaller tire. I change my pressure from 6 1/2 to 8 , depending on the conditions.. They work around 8, but every now and then they will rotate 1/4 turn before they hook, then I back off the pressure. 32 X 14.

[doglover44]

How long does a set of Slicks last in 9.90 racing !

[1320racer]

depends if you have a tire deal or not.