OK...I am installing an AA SC and have decided to also install a ltw flywheel and new clutch. But which one and what clutch? UUC AA or ? Stock M3 clutch or M5 ??? This is going on a 97 M3 Please advise!
Thanks
mg
:dunno

i have the UUC stage 2 w/ e34 M5 clutch, but its only got 100 miles on it so far so i can't really tell you my impressions of it yet.

Andy,
Are you supercharged? and how is the rattle?
thanks
mg

I've got the UUC Stg 2 LWF and M5 clutch combo. It works great w/ my AA SC. I'm @ ~1800 miles thus far. Clutch engagement is like "buttuh". And the clutch grabs on pretty well.

Chatter is minimal, but I believe Karl @ AA can increase your rev @ idle so that the chatter noise is eliminated.

I've had UUC stage II with M5 clutch for almost a year (7k miles) and just recently added the AA SC. It was fine before SC, now my clutch is slipping I think, but I was told by some BMW experts that it's normal behavior for a little slipping, but the extra power makes it worse! I just need to adjust my driving style I guess... if I was to replace my clutch again I would go with something stronger like a Sachs race clutch, but that's just me!

And yes, the rattle is there, specially when the car gets hot and the AC is on!

hey FLMCoupe, have you tried removing your "Clutch Valve". Rob Levinson from UUC said that the clutch valve will make your clutch slip even if your clutch is in good condition. Here is a link to the write up:

http://www.uucmotorwerks.com/html_techtip/techtips/check_valve.htm

You might want to give it a shot.

Originally posted by ADVANT123
hey FLMCoupe, have you tried removing your "Clutch Valve". Rob Levinson from UUC said that the clutch valve will make your clutch slip even if your clutch is in good condition. Here is a link to the write up:

http://www.uucmotorwerks.com/html_techtip/techtips/check_valve.htm

You might want to give it a shot.

Def' kill that valve. It reduces the ID on your slave cylinder down to a pin hole which causes it to engage too slow at WOT b/c the fluid can not pass fast enough to keep up with a fast shift. I have done three of 'em now and it only takes a few minutes. Besides, it is a FREE mod :buttrock

JT

Originally posted by ADVANT123
hey FLMCoupe, have you tried removing your "Clutch Valve". Rob Levinson from UUC said that the clutch valve will make your clutch slip even if your clutch is in good condition. Here is a link to the write up:

http://www.uucmotorwerks.com/html_techtip/techtips/check_valve.htm

You might want to give it a shot.

Whereas this is indeed the first thing that would spring to mind, the M Coupe/Roadster is not supposed to have the CDV like the M3, even though all other components are identical.

However... what certain BMWs are "supposed to" have is not always the case. For example, the E46 M3 is not supposed to have the valve, but we have found examples that do. So, no matter what, it is worth checking the car to see if the valve is in place.

Another thing to consider is if you are not experiencing clutch slippage, but actual tire spinning. A lot of current performance tires do not necessarily make a chirp if you break traction, and with the LSD keeping the car going straight, you might not realize. See if you can have someone watch from the roadside when you do a hard shift with the suspected slippage happening, they may be able to hear or see the tire spin.

If all else fails and the clutch is really slipping, there are a variety of excellent options including the Sachs Sport clutch and other aftermarket choices.

- Rob

Thanks for the tip and the link. I'll look into it to see if I can remove the check valve. While we're on the subject of clutches, here's some new videos I just made from a better angle that show the revs when the clutch is slipping. I think it's my driving style, might need to slow my shifting down or slow the clutch engagement a little. Take a look and let me know what you think.

Here's a video (http://www.fastjam.com/sc/sc6.wmv) of 2-3 shift where the problem usually happens. You can see the revs drop slowly as the clutch engages.

I still don't think it's the tires, you can really feel it in the M Coupe, here's 1-2 video (http://www.fastjam.com/sc/sc7.wmv) that shows what the car does when it looses traction.

Last video (http://www.fastjam.com/sc/sc8.wmv) shows what happens when I shift "smoother" in 1-2 and not as smooth in 2-3. In 1-2 shift the revs drop quickly but not in 2-3.

BTW, this never happened before the S/C, but I did experience the stock clutch slipping, and that was worse than this! Does this mean my car is making too much power for the M5 clutch? I haven't dynoed the car after the S/C install, but I did right before it and my car made 216 rwhp.

That looks like the clutch is hanging up a bit, same symptom as the CDV.

Another thing to be suspicious of is the slave cylinder itself. We have been diagnosing quite a few lately that feel weird or have odd engagement, and the problem turns out to be the internal piston seals are hanging up a bit. Replacement is cheap, about $50 for the part.

Rev-matching will help a lot, improve your acceleration times, and extend the life of all the drivetrain components.


Originally posted by FLMCoupe
BTW, this never happened before the S/C, but I did experience the stock clutch slipping, and that was worse than this! Does this mean my car is making too much power for the M5 clutch? I haven't dynoed the car after the S/C install, but I did right before it and my car made 216 rwhp.

From my own turbo experience, I seriously doubt it's a question of too much power. The thing is, there are a lot of factors to consider in an accurate diagnosis.

If you do investigate a replacement, consider one of the SPEC designs with the improved pressure plate that gives even more clamping force.

For an overview of clutch materials, click here (http://www.uucmotorwerks.com/CLUTCH/).

- Rob

Rob/others -

FWIW, in anticipation of installing a twin-screw on my M Coupe, I'm currently considering an E34 M5 SPEC 2 clutch with UUC's Stage II (8.5 lb) flywheel.

Neil

FLMCoupe, this is a little off-topic, but damn your car is sick! Do you have any movies of acceleration in 3rd or 4th gear from low RPMs? I'd definitely like to see a 0-120 run if you could(dont get pulled over!!!). From those videos, it looks like a clutch related problem.

Rev-matching will help a lot, improve your acceleration times, and extend the life of all the drivetrain components.

On upshifts??? I always rev-match on downshift, specially at autox, which is what the car is used for mainly. Rev-matching on upshift is a waste of time as it slows down my shifting. I don't think the revs drop down that fast that it requires rev-matching.

I'm not that mechanically inclined, although I did the S/C install in my garage, I'm not confortable with working on the clutch, plus I would need access to a lift. I will take the car in to a local BMW shop that I trust, who also did the install on the FW/clutch, and mention the suggestions you made. Thanks!

Where can I find more info on the spec designs? Where can I get them from?

ADVANT123, I don't have any 0-120 videos with SC, but I do have some autox/track videos if you're interested. Here's one (http://www.fastjam.com/mcoupe/videos/seb-sccoupe.mov) of me chasing an AA S/C Coupe at Sebring. I'm hoping to be back there next month to try the S/C!

Just got my car ('99 e36M3) back today with the UUC St2+M5clutch and a new Dinan SC. In some ways it's too bad that I can not clearly differentiate the impact of the two mods, but all I can say is woo-hoo. This is one impressive combination. Having removed the CDV and using RedLine MT-90 in the tranny as speced by Rob at UUC, the clutch take up is fantastic and noise free, and the spool up from low revs is notably superior, though surprisingly subtle - I just notice everyone has suddenly disappeared behind me!!! Clutch feel is light, but I am used to it within a few hours - no probs. Highly recommended so far. Doug

Originally posted by FLMCoupe
On upshifts??? I always rev-match on downshift, specially at autox, which is what the car is used for mainly. Rev-matching on upshift is a waste of time as it slows down my shifting. I don't think the revs drop down that fast that it requires rev-matching.

Absolutely on upshifts! You've got a choice - wait the milliseconds for revs to drop (which they do quickly with the lightweight flywheel), or waste power and abuse the clutch by "forcing" the transmission and engine speeds to match up... which takes just about the same time. A fully-engaged clutch is transmitting more power than a slipping one (slipping even in normal operation).

I'm not that mechanically inclined, although I did the S/C install in my garage, I'm not confortable with working on the clutch, plus I would need access to a lift. I will take the car in to a local BMW shop that I trust, who also did the install on the FW/clutch, and mention the suggestions you made. Thanks!

Originally posted by FLMCoupe
Where can I find more info on the spec designs? Where can I get them from?

www.specclutch.com for info. We have sourced them for our customers' special applications, and offer the service.

Originally posted by mgatepi
Andy,
Are you supercharged? and how is the rattle?
thanks
mg

yep, AA s/c since sept. so far no rattle that is evident, but as i mentioned, only about 100 miles so far so i haven't really gotten to play yet and get everything hot to see what i does then.

Ahh..the awesome power of BF.com!!! Thanks for the great info!! Rob....it looks like another order for you!! Any great deals on a combo Stage II flywheel, M5 clutch and SSK for a 97 M3??
Thanks
mg

Rob,

It doesn't look like I have one... I jacked the car up today and took a look...
http://www.fastjam.com/mcoupe/slave/slave1.jpg
http://www.fastjam.com/mcoupe/slave/slave2.jpg

Forgot to mention in my other posts, around the same time I had the FW/clutch replaced I had a leak in the clutch line and the shop replaced it with a stainless steel one.

http://www.fastjam.com/mcoupe/slave/line.jpg

Could that be the cause of the "delay"? Maybe it's too narrow to allow the fluid through fast enough? Will probably be taking the car back to the shop this week to put the stock line back in, anything else I should have them look for?

Thanks for your help.