Bubstr

The only sure way to tell if your air pressure is right, is with a pyrometer. Taking temp. readings from 3 spots across the tire. When matching up side to side, it can tell you if your getting equal loading. I realize not everyone has one of these, but I have heard that the trigger pull lazier ones for the kitchen work ok, plus they are cheaper. You will want these readings as soon after a launch as possible. Have someone waiting for you at the turn off. You want even temps across the tire and even side to side.

There are several things that can load then unload your rear. Most of the time it has to do with power to traction.

The first situation is not enough power for traction. You will have stored energy in rotating mass of engine and fly wheel/ converter to load it but as soon as stored energy is disapated, your not at high enough RPM to create enough torque to maintain it. (dead hook) The fix for this could be as easy as launch RPM or stall speed or even a rear gear change.

The second situation is too much power for traction. This is basically buzzing the tires. The exact opposite of the first.

The sweet spot is in between these two.

Both cases are a balance between power and traction. Given that you have tires optimized with size and air pressure, the trick is to speed up or slow down wheel speed with gear or launch RPM. The converter plays a big part in this. Getting air pressure right to keep from distorting tire contact patch is first on your priorities. It is true that too much separation can distort tire and can be tamed wit IC settings and shocks, but before you go that way try getting air right first, then if you have to change settings you may have to change tire pressure again, but not much.

fishman1

Thanks for the replies guys

I went to a new track this last weekend and my car didn't hook like it does at my track....i figured it was a good idea to play with tire pressure and shock settings

tried loosening the shocks twice in a total of four settings and lowered the tire pressure three times in total 1 1/2 psi..well the sixty foots killed me, so i tightened the shocks up in total 8 settings from the loose setting and played with air pressure and also lowered launch rpm by 200 rpm finally got some of my sixty foots back but was still shy about .04 on 60 foots but the car ran just about the same as my track.......as this is new for me i am guessing the track was not as good as mine so by stiffening up the rear shocks and dropping the launch rpm i was not hitting the tires as hard and the car would hook better........so this is what i am gathering tight rear shocks u can go higher on air pressure and have to drop launch rpm and loose rear shocks u can go down on air pressure and up on launch rpm............let me know if i am on the right path........thanks.also my slicks are just about 3 years old with close to 250 passes on them but there is lots of thread left but outsides are scuffed so i am going to try applying tire bite first to see if it helps before i but new tires

johnracer

You really need new tires!! The sidewalls are probably dead after 250 runs.....My 60's will usually start to go away after 100 runs or so.
Johnny

fishman1

I would have to agree with you as last night i cleaned up the tires real good and used a light to go over them and since the last time i checked them the tires have really took a turn for the worse, time for new tires.........i was wondering with the short wheel base car and light car wieght with me in it is 2600 lbs maybe i should go to a softer compound with a stiff side wall for the new tires.........what u guys think......thanks

itsabird

if you are hitting the tires to hard, and it sounds like you are, a stiffer side wall could help the hook and unhook condition.

fishman1

yes i agree am looking at goodyear eagle's d1160 with soft compound with stiff sidewall.......they are for light cars but wear out earlier but will hook up better