Supra Forums banner
1 - 19 of 19 Posts

·
Registered
Joined
·
1,340 Posts
Discussion Starter · #1 ·
i'm having a horrible time trying to get a good pass out of this car. i have been going to the local 1/8 mile track and last night i went to the 1/4.

my car is felling so slow on the track and it's really killing me. last night i was running 24psi on my 67mm turbo and the best i could muster was a [email protected]

i know this is way low, and my buddies said they saw sparks coming out from under my car. ( i'm running a SOUTH BEND FERAMIC)

how bad is my clutch killing me? on the highway from a 3rd gear pull the car feels great and pulls super hard; then i go to track and the car runs like shit.

i can't get a good launch, car doesn't pull and the clutch slips and it only slips at the track..

any advice??

btw. this clutch only has like 1500 miles on it.
 

·
Registered
Joined
·
9,759 Posts
sounds like you are overheating the clutch in the burnout box....causing it to slip, which is obvious by the low traps....I am not a clutch guru, but just an observation so I cant reccomend any other advice.

Jason
 

·
Registered
Joined
·
1,340 Posts
Discussion Starter · #4 ·
hey larry!! car is lowered and i was on my kuhmo 255's. i have ET DRAGS but the clutch won't hold them
 

·
Premium Member
Joined
·
11,269 Posts
SO you have a tire that sucks at the track and a car that will not weight transfer.

What do you expect?

This is why supras get a bad rap at the track..... they do not prepare the car.
 

·
Not so boring anymore
Joined
·
7,085 Posts
how bad was the clutch slipping.. 115 is pretty low for 24 psi.. but yea, probably over heating the clutch causing it to slip the whole way.. did that for me when tried launching my car.. slipped every gear.. let it cool downand no problems...
 

·
Registered
Joined
·
106 Posts
I have been having the same problems.. I have a .60 trim CT26 @ 18psi with MAFT PRO, 550's, BIC DDP... Enough to hopefully run some 12's but the best I could do was a [email protected] One thing we have in common: I have a SOUTHBEND DXD-F series clutch as well.. and it SUCKS. It feel so notchy, like I cant shift fast enough, like I could with the stock clutch. I mean, I can barely chirp second gear. 3 days ago the clutch finally gave out on me after about 1500 miles. (No Lie). I paid 575.00 for the clutch and got to drive it a total of 7 times maybe... Should have went SPEC. :(
 

·
Registered
Joined
·
504 Posts
Had similar problem with my HPF feramic when heating it up too much (rolling it out of the burnout box) on one particular run. People said they saw sparks and the clutched slipped really bad. Traps went from 130mph or so to 112mph on that run. Didn't roll it out the next few times out and trapped 133-134mph. Now it's undriveable and we're replacing the pressure plate.
Are you rolling out of your burnouts?
 

·
Registered
Joined
·
2,739 Posts
Hey Malloy, besides the clutch having issues I bet the heat could be killing your power too. Last year, I took my car out on a 88 degree evening and could only run a 13.5 at 107mph. I would usually run an easy mid-12 at 116-119mph with my old SP61GT. The 7M's stock ECU does not like heat, even with race gas. I bet in some cool conditions your car will run a lot better, and your clutch will probably like it better too.
 

·
Project:: Reaper
Joined
·
1,401 Posts
Phyrx said:
I have been having the same problems.. I have a .60 trim CT26 @ 18psi with MAFT PRO, 550's, BIC DDP... Enough to hopefully run some 12's but the best I could do was a [email protected] One thing we have in common: I have a SOUTHBEND DXD-F series clutch as well.. and it SUCKS. It feel so notchy, like I cant shift fast enough, like I could with the stock clutch. I mean, I can barely chirp second gear. 3 days ago the clutch finally gave out on me after about 1500 miles. (No Lie). I paid 575.00 for the clutch and got to drive it a total of 7 times maybe... Should have went SPEC. :(
yea its definitely yur clutch. i had the stock Ct-26 550 Lex AFM and 3inch exhaust, MBC set to 16 psi and WG shimmed to hold 13 PSI to redline and my best runs on 235 Potenzas on Lexus IS wheels were VERY consistent 13.4 @104. on a Spec Stage 3 clutch. change out yur clutch for a better one......
 

·
Flying Dutchman Pilot!
Joined
·
2,172 Posts
Clutch and tires are the basics for going to the strip. You don't have either. You're not going to go fast on street tires. I wouldn't have brought my car to the track if I didn't have both of those. Get a clutch that can hold and put the ET drags on and say a little prayer for your driveline because if you hook those tires and 60' the car, sparks coming out the bottom will be the least of your problems. If you really want to get spicy put the stock springs in and remove the sway bars while you are at it.
 

·
Registered
Joined
·
1,340 Posts
Discussion Starter · #13 ·
well i thought i have a good clutch. supposly this clutch is rated to 600ft lbs. i guess not. i'm really torn on what clutch to go with.

btw.. i do have 15X8 centerline telstars with ET DRAGS. however i tried that route 2 weeks ago and the clutch couldn't handle it
 

·
6Spd TT Aerotop
Joined
·
3,620 Posts
Get yourself a good carbon twin/triple plate, those things LOVE heat and will just grip harder the hotter they get.

Dan.
 

·
Flying Dutchman Pilot!
Joined
·
2,172 Posts
I find that clutches are rated closer to flywheel numbers than rear wheel and they usually fail with even less torque than advertised when drag raced. A company in TX will make you the parts needed to run the tilton triple carbon if you wanna pay 4500. Other than that I have yet to find a single disk clutch that can survive the 1/4 mile in the MKIII, even the RPS DD plate. I broke three of them, but I'll say this, none of them ever slipped.
 

·
Not so boring anymore
Joined
·
7,085 Posts
rps twin carbon?

how are exedy clutches.. i may try one of their twin discs..
 

·
Project:: Reaper
Joined
·
1,401 Posts
i dunno how the twin disc is but i know exedy is like a cheaper brand. i remember getting a stock clutch for my DSM and exedy was the cheapest on the list. so i dunno. i wouldn't trust em
 

·
Registered
Joined
·
6,709 Posts
well the problem with the7m motor

unlike the 1jz and 2jz of the world that have choices of exedy, ATS, etc.

We have tilton triple carbon or ...... tilton dual carbon and that is about it. No one else makes a setup for us :(
 
1 - 19 of 19 Posts
Top