AmericanMuscle33

Ok, here's the deal...after about an hour of searching the forum I partially answered some of my questions, but would still like to get specific opinions.

OVERVIEW: my Car: bone stock LT1, 150,000+ miles, aggressive auburn carrier, more aggressive 4L60E, 4.10 Gm gears, strong driveline...trying to see what kind of times my tired Lt1 is capable of prior to engine rebuild...

Last time i went to the track i pulled a 13.9 + 98mph, with a 2.0 60'ft on balding craptaffic Kuhmo's...i was launching with Eibach Sportlines front and rear, and AGX's at stiffest setting...i was also breaking loose every 1-2 shift due to very aggressive shifts...a buddy of mine just brought me 2 M/T Slicks (28.0 x 9.0) mounted on 15 inch wheels. The tires are also bead-locked to the wheels via approx 8-10 screws on either side. He uses them on a built 1st gen that he drives maybe once a year...he said these tires and wheels were brand new 10yrs ago, and that he's put 2 passes on them since....they still look brand new...

I test fitted them today, lil rubbing...so i rolled both rear fenders...both tires now tuck...for track use I will be re-installing stock rear springs to raise ride heigth approx 1.5-2in in rear, and will be setting AGX's to softest setting in rear...

QUESTIONS: 1st: how much PSI can i run with these tires bead-locked? on one thread concerning a non-beadlocked M/t someone recommended starting at 16psi and working your way down.

That is my main question...as far as heating the tires, and launch technique, I've come to the conclusion from reading threads that its a case-by case basis, and is more of a feel it out yourself...see what works kinda deal...He requested i put not more than 5 passes on the tires, and to "not destroy them"...anyhow, whats worked for me in the past with my car on street tires is a healthy burnout, and stalling as high as i can, instead of flashing...

PLAN: i plan on warming up the tires, they've been sitting and need a good cleaning...perhaps 3-5 seconds of smoke, and roll out of it...i figure i'll start with 15psi (unless you guys say otherwise due to bead-locks), and will stall as high as i can...I've never launched with slicks before, and due to the small amount of runs i'm allowed, I'm going to try to find the breaking point of the tires in the first run if possible...I'm assuming high stall, pedal to the floor soon as i lift off brake will do the trick...if you guys have any other tips, or ideas, they'd be much appreciated...

All I really want is a couple tenth drop in 60'ft, and to hook during the 1-2 shift...if that happens, I'll be the proud owner of a Bone Stock LT1, with over 150,000 miles, that runs mid-13's...last time i showed up at my local track, the "new guy" running the Tech Inspection laughed at me when i told him my stock Lt1 runs sub 14's with the miles it shows....I intend on proving him horribly wrong...

Sorry for the longest post in my history of posting...Thanks,

rskrause

I'd try start at ~15psi and work down. They may not work as well as you think - 10yo rubber is going to be pretty stiff. Do one hell of a burnout the first couple of times to try to expose fresh rubber.

Would you use a 10yo rubber???

Rich

Stephen 87 IROC

Bead locks and rims screws are 2 different things. You only need to use rim screws if you start rotating the tires on the rims. Put some shoe polish on the tire right at the valve stem. After a day of racing, check to see if the shoe polish mark is in the same location. If it's starting to move on the rim then rim screws should be used. I don't think you're producing enough torque to spin the tires on the rims yet but if they already have rim screws, don't worry about it. Very fast cars with 33x16 tires only have about 5 psi in the,

I don't think a heavy street car will like very low tire pressure. The 28 x 9 tires in a 3500+ pound car will probably work best in th 15-20 psi range. Finding the best tire pressure is trial and error since no 2 cars are exactly the same.

I'd also get rid of the 10 year old tires and get some new ones. The rubber is probably dried out.

Rim screws are manditory if you run tubes in the tires more for your own safety. If you spin a tire on the rim with a tube inside, it will tear the valve stem off the tube.

AmericanMuscle33

Yes, my mistake....they are rim screws not bead-locks...and yes the tires are tubed, and since these were used on a vehicle producing much higher tq numbers than mine, that all makes sense...after weigh in, my car *cough* only weighed 3330lbs...but with the extra fuel I have to carry to make it home from the track, plus my weight...i'll prolly be racing at the 3500lb range...

Hmm...well thanks for all the info guys...

far as using a 10yr old rubber...i'd sooner use a ziploc bag...but since these are M/T's, and a freebie...I figure I might as well go experiment with them...

Stephen 87 IROC

Can't go wrong with free tires. Use them until 60' times fall away then buy new rubber. Many racers sell off their old tires that still have enough rubber on them because they're not consistant enough any more.

I buy a new set of slicks every year. If I'm lucky, I can get 2 seasons out of them. The last time I had my car on the scales, the race weight was 2975. It's a 100% race car though.

rskrause

Mine work best at 12-13psi and my car weighs in at 3,850 and traps >140mph. Feels a little loosey goosey at the big end, but not terrible by any means.

Rich

stealthblack

same as above except for the trap speed
as far as 10 yrs old, id have em balanced to make sure they didnt go out of round.then paint em if you have some trackbite or equivalent[its legal in drag racing, car # 41!] then do a stupid burnout, that first pass it wont hook because theyll be too hot but that might restore em, might not.

i was BSing with the MT rep at the last PSCA race and he said he liked to see 30-50 deg more than track temp, up to a point. I do a 2 gear medium rev burnout and go a little hotter than most because i dont hook for a damn.