Mcleod twin disc issue?

[Big50]

Took the car out Wednesday to the track with my newly installed Mcleod twin disc. Clutch has been broken in properly and this is the 2nd time out. Everything went fine at the track pulled several 1.70 60' times. Anyway on the way into work i went to pass a slow truck and gave it a little gas in 5th. Clutch slipped, a bit. Reved up about 300 rpms and then took off. So, i thinking wtf! I do it again and same thing it slips.

So, i just called Mcloed tech line and they told me that there is a lot of stress in 5th gear which i am aware of. The only thing is i never had this happen with my old clutch. Also, i have 4.10's so my rpms weren't that low. they were at 2600-2700 when i gave it some gas. I think i actually noticed this on the way to the track earlier this week. But it held up fine. Anybody have any input or experience with this.

 

[lito]

Just one curiosity that does not mean anything at all.

What flywheel do you have? and is it an RST or an RXT?

Well, those were two curiosities.

 

[Big50]

Just one curiosity that does not mean anything at all.

What flywheel do you have? and is it an RST or an RXT?

Well, those were two curiosities.

RST and it's a new stock flywheel.

 

[lito]

The RST and the stock flywheel has a different contact area and that gave some people some problems. Someone here posted a picture of the issue.

 

[klaw]

My RST didn't last long at the strip. Went RXT and it's holding up well.

 

[Big50]

My RST didn't last long at the strip. Went RXT and it's holding up well.

Really? I have heard nothing but good things about the RST. My buddy has over 200 passes on his. I just can't believe i'm having more clutch issues. This is my 3rd clutch since my rebuild was finished in April. I'm ready to set my car on fire. I just want it to work like it's supposed to.

 

[dysan]

Alot of people knock Spec but I've had nothing bad to say about my Spec 3+ clutch at all. It's holding great, extremely light pedal, knocking off 1.62 60's on my 17" stock rims with M&H 28" tall drag radials.

If you've got to replace it, I've got to recommend the Spec 3+. Hopefully you can get it taken care of though.

 

[klaw]

Really? I have heard nothing but good things about the RST. My buddy has over 200 passes on his. I just can't believe i'm having more clutch issues. This is my 3rd clutch since my rebuild was finished in April. I'm ready to set my car on fire. I just want it to work like it's supposed to.

The flywheel issue is real. The stock flywheel has a larger inner friction surface diameter and the RST clutch disk will hang off the inside by half an inch or so. It seems like once the RST starts to slip it gets worse in a hurry. Between two slave cylinder leaks and the RST letting go, I've had my trans out three times in the last year. The RXT setup and OEM slave are working fine now.

This thread is a good read on this issue (check out the pic in post #17):

http://www.s197forum.com/forum/showthread.php?t=40109&highlight=flywheel

 

[NastyStang113]

Did you hot lap it at the track? Twin discs generally need much longer time to cool down between passes. The RXT is much better at this though.

 

[klaw]

Did you hot lap it at the track? Twin discs generally need much longer time to cool down between passes. The RXT is much better at this though.

First pass of the night. Burnout went fine. Clutch let go when I pulled third. Didn't try another pass - stunk the pits up pretty bad. Drove it home though. It would hold street driving OK with a slight engagement shudder.

 

[NastyStang113]

What about you OP?

 

[Liftedbronco]

just to relate a little - i stunk up the track with my clutch one. frpp billet steel flywheel, centerforce dual friction clutch. Did a burnout but missed the water box. second gear burnout, redline...only the tires werent spinning. I have it on video too. The attendant there is waving his arms wildly like STOOOP! lol. my bad. i still made a pass anyway.

 

[circusboy]

I went RST and it failed. There was an issue with a batch that had inproperly drilles holes in the outer ring. It was my 5th clutch. it made me go auto lol. I missed the stick so i went back. I went RXT this time. Not one issue at all and I wast running 17 pounds of boost on the old turbo setup.

 

[Big50]

What about you OP?

Took it out during break at work. Slips on in 3rd,4th, and 5th when it's at lower rpms and i floor it. Oddly enough, it holds fine under full throttle. Revved it up to about 3300 in 2nd floored it through the gear shifted hard to 3rd and it held all the way through.

So, i then called Lee at mcleod told him what was going on. Said it could be a number of things from the screws backing out to improperly installed to manufacturer defect. So, now i have to have it pulled and start with sending pix to possible sending it out to Mcleod.

Oh, and i spoke with the shop who installed it and they used the larger. 11" fly wheel instead of the stock 10.5" so i guess that possibility is out the window.

I don't necessarily mind having the car down again. I just can't face telling my wife i'm taking it to the shop again for the clutch for the 5th time

 

[BruceH]

Took it out during break at work. Slips on in 3rd,4th, and 5th when it's at lower rpms and i floor it. Oddly enough, it holds fine under full throttle. Revved it up to about 3300 in 2nd floored it through the gear shifted hard to 3rd and it held all the way through.

So, i then called Lee at mcleod told him what was going on. Said it could be a number of things from the screws backing out to improperly installed to manufacturer defect. So, now i have to have it pulled and start with sending pix to possible sending it out to Mcleod.

Oh, and i spoke with the shop who installed it and they used the larger. 11" fly wheel instead of the stock 10.5" so i guess that possibility is out the window.

I don't necessarily mind having the car down again. I just can't face telling my wife i'm taking it to the shop again for the clutch for the 5th time

It's not the outside diameter of the flywheel, it's the inner diameter. The stock 11" has less surface area in contact with the clutch than the Fidanza in the picture I posted in the referenced thread.

 

[Big50]

It's not the outside diameter of the flywheel, it's the inner diameter. The stock 11" has less surface area in contact with the clutch than the Fidanza in the picture I posted in the referenced thread.

Thanks, i spoke with Tom@amped he pointed that out.

Spoke with Lee at Mcleod and he thinks its my launching technique. I drop the clutch at 2500 rpms. He said that it puts to much strain on the clutch. Said something about dropping it around peak tq closer to 4000 rpms would be better. Which i don't quite understand because i'm making 400-415 wtq around 2500 and i peak at 462. Or believes there is something coming loose in the clutch assembly do to the fact that i can hear a rattle when the clutch slips, and from what i can tell, the clutch pressure is less than when i got it installed. Either way i have to get it pulled and diagnosed.

I didn't hot lap it. No point in doing that being that the supercharger suffers from heat soak.

Yet another reason to stay stock.

 

[Vapour Trails]

So the thing to do is get the RXT clutch instead?

Jesus, nothing is simple. Thinking about upgrading my trans and clutch makes me want to go back to CAI/tune.