First off I apologize for the long post. But I want to try and include all of the details.

So I went to one of the local 1/4 mile tracks Saturday. I want to start by saying my car has been driving completely normal up until Saturday.

Plan was to trailer it to the track but ended up driving it there (about an hour and a half drive). About halfway to the track I noticed my gears were getting really notchy at lower speeds for some reason.

when I got to the track, we swapped the tires and wheels and let it cool down for about 20 mins. Then went to the staging lanes. When I put it in first gear, the car was trying to creep forward even with the clutch pushed all the way down..

I made a pass, gears shifted fine during pass.. no lockouts or anything.

parked the car and let it cool for 15-20 mins.

while it was cooling we tried adjusting the clutch pedal to compensate for whatever is causing the car to try and creep forward.

In order for the car to stay running with clutch in, and in first gear, we practically had to run the clutch pdeal rod all the way in (no threads showing - if that makes sense)

so it cranks up and will stay running finally.

I made another pass and the clutch completely let go and slipped bad.

so parked the car and called it quits. The car would still go into gear but will not go into reverse whatsoever. We got back on the road and finally made it home.

on the way home car was getting notchy again and hard to shift. I assume it got hot on the long drive and worsened.

I got to my driveway and had to put it in first and it was trying to jerk forward with the clutch in all the way. I barely got it in my garage. And it still will not go into reverse at all.

things we have looked at / tried:

-we bled the slave cylinder (some air bubbles came out, but not much)
-we looked through the inspection hole and it “LOOKS” as if it is functioning correctly
-When the car is off it will go into any gear fine without any obstruction

Car has an Exedy twin disc which I know is insufficient for my power level. I am already planning to upgrade to the triple disc.

the car has a recently refreshed transmission that has about 1500 miles on it if that and has never given me an issue. (Faceplated 1-2 gear. Carbon 3-5 synchros. Billet output tube, rem treated gears)

however I’m nervous about getting it on to a trailer, much less getting it to the shop that does most of my work.

it’s sitting in my garage right now. I have never pulled the trans on this car before... but I may end up having to try and do it myself

Just looking for any pointers / advice on what I can do in this situation.


TL;DR-
clutch not engaging or disengaging properly and I don’t know how I am going to get it to a shop....

 

My simple guess is that something has broken or worn down in your clutch, but
Couple questions...

How much HP do you have that you think a exedy twin is not strong enough?
if the trans only has 1500 miles on it, is that the case for the clutch as well? If not, how many miles are on the clutch?

 

820whp and 517ftlbs and I believe the twin is rated for 500 at the flywheel. I should have upgraded to a triple earlier but I guess I was chancing it. transmission has 1500 miles or so. Clutch has around 3k. But does have probably 10 launches / 1/4 mile passes on it.

 

The exedy HD twin does fine up to about 570wtq.

My car makes about 540wtq and the HD twin is fine.

 

Well I have a video where the clutch completely slipped on a 3rd to 4th shift at the track. And the clutch only has 3k miles on it.

 

If it slipped at 520wtq, there is another issue. The clutch holds that torque if everything is correct.

 

Car has been fine on this clutch street driving and several other track outings. The twin is not “MEANT” to handle over 500wtq. Keyword being meant. Sure, it will last for a while as it did for me. But it will let go, also, like it did for me.


This is straight from the description of the Exedy clutch


“For high-powered applications, EXEDY offers twin and triple Multi-Plate clutches. These are designed for high power street action as well as drag, road and rally racing. The twin plate clutches are rated for approximately 500 ft/lbs of torque and the triple plates are rated for approximately 800 ft/lbs of torque, both figures at the flywheel. Twins come with both spring damper discs or solid discs depending on application, whereas triples are all solid discs and not recommended for street use.”


And fwiw, here is the slipping in the video.

 

Ok. But like, you're wrong/misinterpreting the information here.

Unless you have an SD pressure plate (which I highly doubt as most places usually have the HD on sale for less than the SD), the HD Twin (MM022HD) is rated for 615wtq. Keeping it around/below 570wtq prevents slipping when it gets hot from being launched.

You can do with this information what you please, but your car is having a problem. And it's not because you're running an underrated clutch.

 

Ah okay. MAP’s website is misleading with that info. Well regardless, the clutch slipped. I guess it could have gotten hot..? But that was only the 3rd pass in a 3 hour span.

and like I said clutch has been fine up until that point.

 

You either got it way hot, or there's an issue. The shifting problems pint to an issue though. Only thing to do is tear it down really. I've seen the basket bolts backout, so thats a possibility.

 

"when I got to the track, we swapped the tires and wheels and let it cool down for about 20 mins. Then went to the staging lanes. When I put it in first gear, the car was trying to creep forward even with the clutch pushed all the way down.."

I had this problem using Exedy Twin Plate HD , could not resolve the issue so finally took the clutch out.
Found out the culprit was the worn release bearing. Replaced it, never had an issue after it.
Generally, these Exedy clutches are very robust and can take alot of abuse.

 

Good point. OP, if you are not using an OEM throw out bearing, you should get one.

 

If he's using the exedy one, that's fine. I'm pretty sure exedy gets the same one as Mitsu does from NTN.

 

This sounds like clutch drag to me. You said you adjusted the clutch rod all the way in and that would move engagement point down. Go the other way such that the clutch catches towards the top. The fact that your car is creeping fwd with clutch in to me screams wrong engagement point.

Also, do you have a clutch fork stop installed? If so make sure its not limiting movement as it needs to be adjusted as the clutch wears.

 

im going to mess with it some more. But I’m certain we tried it at pretty much every point and finally we’re able to keep it running, in gear, with it almost all the way out.

and no, I don’t have a clutch fork stop.