Driver Mod help!!
Thread Starter
Racer
Joined: Mar 2007
Posts: 297
Likes: 3
From: Baton Rouge LA
Driver Mod help!!
I seriously suck at launching. so much that i'm ready to throw an A4 in my z06. video of 4 runs. i was letting off on first 2 runs, third run, you can hear clutch slipping whole way down, 4th run my best ET and trap, but only 1.8 60'. from the burnouts and launches, please help me fix the driver mod. i'm not too worried about the ETs, just wanna get my 60's down and consistent. i don't get much seat time since Ennis, Tx is only open 1 or 2x a month.
launches are at 5000rpm, 14psi heated BFG 315/35/17, mods add up to 562 rwhp, clutch is exedy twin disc. thanks for any help/suggestions.
don't laugh too hard at the vids, i excluded my stalls on 2 burnouts 
launches are at 5000rpm, 14psi heated BFG 315/35/17, mods add up to 562 rwhp, clutch is exedy twin disc. thanks for any help/suggestions.
don't laugh too hard at the vids, i excluded my stalls on 2 burnouts
Race Director
Joined: Oct 1999
Posts: 13,298
Likes: 14
From: Somers NY
From looking at the video it appears you are letting the clutch out when you SEE GREEN ? If thats the case, you should be letting the clutch out on the last yellow... However no matter when you let the clutch out it will have NO effect on your 60' time... and if you are using "STREET" tires a 1.80 is a good 60' time..
The car sounds good, and I really cant tell if your clutch is slipping after you shift to 2nd & 3rd... From what I see on the videos all you need is more seat time... and if you are using street tires I doubt you'll get much better 60' times until you switch to Drag Radials..
Try leaving on the last yellow especially if you ever enter eliminations...
Good luck
The car sounds good, and I really cant tell if your clutch is slipping after you shift to 2nd & 3rd... From what I see on the videos all you need is more seat time... and if you are using street tires I doubt you'll get much better 60' times until you switch to Drag Radials..
Try leaving on the last yellow especially if you ever enter eliminations...
Good luck
Team Owner
Joined: Nov 1999
Posts: 32,782
Likes: 11
From: Former NCM Drag Racing coordinator, National director Corvette Challenge Spring Hill, Tennessee: Whiting, New Jersey
Cruise-In VI Veteran
Cruise-In VII Veteran
[QUOTE=Jeenis;1561530152]
launches are at 5000rpm,
I'm don't know why you didn't break something.
14psi heated BFG 315/35/17,
Way to low an air pressure, I would run around 30 psi. Low tire pressure will cause the tires to cup at launch only putting the outer edges on the track.
mods add up to 562 rwhp,
If this is a true dynoed RWHP, no matter what you do it will be hard to get the car to 60' without slicks and chassis work and at that piont you'll start braking parts.
launches are at 5000rpm,
I'm don't know why you didn't break something.
14psi heated BFG 315/35/17,
Way to low an air pressure, I would run around 30 psi. Low tire pressure will cause the tires to cup at launch only putting the outer edges on the track.
mods add up to 562 rwhp,
If this is a true dynoed RWHP, no matter what you do it will be hard to get the car to 60' without slicks and chassis work and at that piont you'll start braking parts.
Race Director
Joined: Aug 2000
Posts: 10,649
Likes: 31
From: Central Florida
Opinions vary. Here is my take.
In my testing of BFG 315.35.17, spinning them in a parking lot at various psi from 24 to 12, they begin to cup at about 15 psi. But I'd suggest running 18 psi (hot); readjust the psi before each pass. That pressure will help absorb some of the shock on launch and shifts.
They won't handle a launch much above 4200.
Traction System Off, that's one push of the console button.
The burnout procedure is here: Burnout Without a Line Lock Also suggest watch the two C6Z vids under "driver cred." They show the burnout. You need to be very careful with the water and the positioning of the rears. Opening the door to look at the rear tire helps (1) avoid too much water and (2) starting the burnout in the correct spot, which is just forward of the damp area.
The launch procedure is here: General Launch Techniques You're seeking about five feet of wheel spin, a hook and then an explosive rpm climb. That will be achieved by the right launch rpm, fast clutch release, and a throttle squeeze calibrated to avoid breaking the tires loose again.
Finally, I would suggest not intentionally slipping that dual-disc clutch.
Ranger
In my testing of BFG 315.35.17, spinning them in a parking lot at various psi from 24 to 12, they begin to cup at about 15 psi. But I'd suggest running 18 psi (hot); readjust the psi before each pass. That pressure will help absorb some of the shock on launch and shifts.
They won't handle a launch much above 4200.
Traction System Off, that's one push of the console button.
The burnout procedure is here: Burnout Without a Line Lock Also suggest watch the two C6Z vids under "driver cred." They show the burnout. You need to be very careful with the water and the positioning of the rears. Opening the door to look at the rear tire helps (1) avoid too much water and (2) starting the burnout in the correct spot, which is just forward of the damp area.
The launch procedure is here: General Launch Techniques You're seeking about five feet of wheel spin, a hook and then an explosive rpm climb. That will be achieved by the right launch rpm, fast clutch release, and a throttle squeeze calibrated to avoid breaking the tires loose again.
Finally, I would suggest not intentionally slipping that dual-disc clutch.
Ranger
Last edited by Ranger; Aug 17, 2007 at 09:19 AM.
Le Mans Master
Joined: Jun 2003
Posts: 9,251
Likes: 217
From: 2007 Nat'l Corvette Challenge 11.50 index Champ. New Jersey
I agree on the rear PSI.
I think your first burnout may have been a little too long, the 2nd one too short, & the third one a tad too long.
You're slipping the clutch too long (1st & 3rd launch), probably causing it to glaze/overheat, causing it to slip....
Looked like the 2nd pass you were headed towards the center line pretty far as well....Not ripping you, just telling what I saw....
How is track prep usually at that track??
Ron
I think your first burnout may have been a little too long, the 2nd one too short, & the third one a tad too long.
You're slipping the clutch too long (1st & 3rd launch), probably causing it to glaze/overheat, causing it to slip....
Looked like the 2nd pass you were headed towards the center line pretty far as well....Not ripping you, just telling what I saw....
How is track prep usually at that track??
Ron
Safety Car
Joined: Jul 2002
Posts: 3,529
Likes: 1
From: Rehoboth MA
With my stock C5Z, it took alot of practice and patience. I was given alot of advice from Ranger and TurboZ06, and it helped greatly. After alot of messing around, one day it just all clicked. My 60' went from mid 1.90's to consistent low 1.80's then down to low 1.70's and my best being 1.664. Repetition is def my friend. I bracket race my car every week, '06 was a learning year for me. But about 1/2 through this season I started being able to get good consistent reaction times in my car, it wasn't easy to learn, but I kept practicing and never gave up. Every test and tune I could go to, I went to. My driving has become very consistent over time as well, I can make 2 passes in a row and it's not unusual to have no more than a 3 hundredths difference between the two. Right now I'm 10'th in NED St Pts, but I'm gonna be the first to tell you, it was a long road for me, lots of practice and patience. It was alot of hard work. This is the first manual trans car I've ever owned, I've been bracket racing automatics for the 5 years before that.
