WIKU

Took my car to palm beach raceway. Car is a 01z with a cam(224-230) lg 1 3/4 long tubes/ vara ram/ under drive pulley. The car was tuned like 7 years ago and it made 420/400 to the wheels. I took the car to the track once a long time ago, and the best pass out of 3 was 12.0@118 on a street tire. . About a year ago I replaced the clutch with a mcleod rxt, and installed 3.73 gears and guts from a c6z in my rear diff. So the night before the track, I installed a set of really old et streets on the 17 inch front wheels and decided to change my spark plugs. We tuned the car with TR55, but now I installed tr6”s. I noticed right away with the colder plug, it was not as snappy as usual.
So I went to the track the other night and the best past was 11.94@119.
Tire pressure was at 17 psi, and I tried to launch at 2500 but it spun or bogged.
What am I doing wrong? I figured this new clutch and gears would of taken me to mid 11’s. I would like to be low 11’s on motor and high 10’s on 100 shot. Any advice would be appreciated. Thanks in advance. Here are the slips , I’m car 4645

WIKU

P.s. it also has a lightweight billet flywheel with the rxt. ( i noticed it’s very difficult it launch this vehicle consistently)

MVR 155

You just need to sort out your launch, on a sticky tire you should be seeing 1.7 or better 60' times. I would also caution using "really old" tires as the rubber begins to break down and can fail..... you definitely don't want a blow out on the big end of the track. 2500rpm is pretty low for a tire like that as well. You are going to need to feel out the track prep, do a good burnout and play with proper launch rpm. Practice.... Practice.... Practice. Do you know what the DA was? You should be seeing a bit more MPH with your setup (121-122mph at least).

WIKU

yeah my thoughts also, i though the car would mph more, oh well. i will be hooking up the lc1 wideband and hp tuners. I will make some runs and see if i need to adjust anything. do you know about what RPM is a safe number to launch at and not to break anything

MVR 155

I would probably start somewhere between 3500-4000rpm with a quick and smooth release on the pedal. You don't want to just dump the clutch as that will really shock the driveline.

MVR 155

Here is a write up/tutorial with some good advice from forum member Ranger.

https://www.corvetteforum.com/forums...echniques.html

Roddy13

a 1.7 60' time would have gotten you mid 11's... you need better tires! Good runs though. Cool story on having the car for so long and still tracking it. I hope you it MID tens on spray!