$600 spent on Hoosiers QTPs and I'm running .2-.3 slower than with my F1s!!! Argh! First time to the track tonight on sticky tires. I normally cut 1.95-1.98 60' times on F1s in same weather. Have tried from idle, 800, 1000, 1200 & 1500 RPM tonight and consistently cutting 1.99-2.01 60s... I am stomping it hard off the launch and it hooks and go (slow). Ran low 8.5s to high 8.4s... should be low to mid 8.3s on F1s in these conditions. Yes, weather sucks and I'm at 2000' altitude but conditions are same as normal, I know this track, know my truck is running good. I am 99% sure there isn't some other problem going on here. I am NOT spinning them off the line. I am STOMPING the gas and she's hooking but just isn't getting anywhere fast. Boost looks good. Got the smoke rolling. I AM spinning the tires on the rim about 1 inch each pass but not enough to hurt me right?

Stock suspension except for spring clamps. Stock stall convertor. If I was spinning this would be a different story but on video (don't have digital or I'd post) she looks like she's squatting pretty good. Folks say I'm not spinning. I am almost certain i'm not spinning. My only guess is the converter isn't locking up right.

Driveshaft loop going on tomorrow morning, traction bars next week but I gotta race tomorrow DOT Street class. Would really like to figure this out. Kinda embarassing Should i stall it up higher and keep romping it? Like 1800?? How high can I stall a stock convertor up? Any help much appreciated!

Justin

 

Sounds like you are hooking up pretty good. Mark the wheel and tire to see if it is spinning on the wheel.
New slicks take a few runs to heat cycle. They will get stickier.
What pressure are you running?
For your own safety do not run with out traction bars your luck will go bad. DS loop is required at most tracks with slicks. Suprised they didn't catch it in tech.
Same goes for the loop GET ONE before you run again.
Keep up the racing just be safe.

 

17lbs psi. like i said, tires ARE spinning on the rims about 1" or less each run, shouldn't be the root of the problem here though. it is hooking. loop going on tomorrow before i race... i have it, and traction bars next week. i've never seen them do tech at my track, at least not on street cars. thx

 

For stock converter I find it best launching at idle with slicks on. My 60' were running in the 1.7x .

 

If the tires are spinning on the rims and you are hooking, not spinning the tires on the pavement, add some air. Add 2 psi, try it. Still the same, add more. My slicks spun on the rim the firest night out racing, since them no more spin. If they're newly installed you gotta get the soap compound used for mounting out from the bead. Just takes a little time, and a few burnouts. Once they stop spinning on the rims you will probably have to start lowering the tire pressure back down to get it to hook.

 

Drivshaft loop not required by NHRA if you are on DOT's and running 11.99+. The slow 60's can be caused by a bad convertor, a local L could never get decent (<1.90) 60's until convertor was replaced.

 

If you were hooking with F1's and are hooking with the QTP'S there is not a difference really. Actually; if you can hook with a regular radial then you will go faster than with a slick. A big slick with lowered air pressure is just like a big flat tire going down the track. Basically unless you need it to get off the line then it is going to hurt you.

 

thanks guys. i still think the convertor isn't flashing at the right RPM. and yeah I agree about the slowing you down b/c of the big fat low pressure tires. truck only has 6,000 miles on it, don't "think" there's anything wrong with convertor but who knows. will try launching at higher rpms for test n tune. sticking with launch from idle for now, which today somehow got me 2nd out of 26 car field, trophy and $250. woo hoo i keep breaking out in the final round, grrrr, I had the guy on the tree tonight and even hit the brakes but too late and broke out by .024. Damdest thing, it was practically a hot lap and was on par to run .04 faster than previous round's ET.

we run IHRA rules at local track but I don't know what the rules are for loops... anyway, got my LFP loop on this morning... I HATE drilling above my head into metal. it was pretty simple install but all things considered if i had it to do over again, i'd pay a few bucks more for the two piece loop. until you do it, you don't realize how sturdy the floorboat is, especially where the panels overlap which is where you drill for this loop. i did notice my driveshaft had touched the exhaust heat sheild at some point from a hard launch.

 

You must be doing something right if you finished 2nd and made $250.00
Get some traction bars on ASAP!. The tire slipping on the rim that much is normal and will stop soon.
Do not drop pressure in the rears if it is hooking up. It can get a little squiggly on the top end. I also increase front tire pressure to 45 psi at the track less rolling resistance. Have fun

 

i have the same problems with my truck. I know it's not the tires because my buddies have put them on and run 1.71's on them. I put them on........1.91's.

I've even put a couple different combos on with the same results.

I'm convinced it's convertor.

My next mod I guess.

It does suck to come up to the line with slicks on and run a 1.9x short time, then have a stock lightning come up behind you and do the same thing on street tires. But trying to launch a modded truck on street tires will be worse.

 

Tallimecca i know exactly how you feel. My best is 1.82, but recently i can only do 1.9's. It sucks, the truck feelsl ike it hooks great, then im dissapointed when i get my slip. My 60 is the first thing i look at when i get a slip. Ah well, i bought a pi 2600 converter, hope it helps for this fall

 

I know this sounds dumb, but count your shifts. if you are just doing a burnout and then pulling to the line, your truck may be launching in 2nd gear. I had the same problem (doh). Just bump it into neutral and rev it once before you come to the line.

Arren

 

That's good advice

 

I did that once; but you realize the problem when you are at the top of 2nd gear. Or for me I realize it when it didn't take off very hard. It was within a few tenths that pass.

 

thx guys... pretty sure it isn't the 2nd gear problem as it's ran within .12 of itself the last 16 passes and although i haven't counted shifts i think i'd know if it wasn't hitting that 1-2 shift. that is half the fun density altitude was about 3800 ft so i am hoping that had a LITTLE to do with it at least. i am fully convinced the issue is my convertor whether that can be changed with different launch technique I dunno.