Jumpster74

iTrader: (1)

After finally completing my BMW drivetrain swap after over a year, my dumba$$ was a little too excited and forgot that new clutches need a break-in period.

I am running an ACT full-face organic setup rated for 460ft/lbs and am making around 330ft/lbs.

I took it for one shorter test drive only using partial throttle to just feel out and listen to the car, then probably 10 miles later, turned on the boost control and attempted some full power pulls. The clutch has been grabbing fine in lower gears at high boost, as I can feel the rear end break loose, but I realized yesterday that 3-8 of my 4/5th gear pulls over a few days of feeling the car out may have likely caused clutch slip as the boost kicked in at 4k+. I know for sure that the clutch has slipped like this around 3x.

Again, the clutch has slipped certainly less than 10x at high gear peak boost, and I let off immediately each time (thinking it was cold tires and wheel spin initially).

Is this enough to ruin a clutch?

I am assuming the options are to now:

1. Attempt the break-in procedure and hope that 500 miles of city driving still can break in the clutch.
2. Attempt the internet "deglazing" procedure (i.e. lightly slip the clutch without building heat to knock off "glazing") https://www.club3g.com/threads/how-to-deglaze-clutch.129181/
3. Remove the clutch and scotchbrite
4. Buy a new damn clutch

The clutch still operates as expected outside of high gear full boost, so my thought is to proceed through those options numerically, but I'm curious what your thoughts are.

curly

iTrader: (25)

You’re only breaking in the disc, so that’s all you’d have to replace, especially at this low mileage.

however you’re right around the limit of the clutch, since you’re at 330ft/lbs at the wheels, and probably close to 400+ at the flywheel. If you can’t fix it with the above tricks, I’d put a ceramic disc in it, those also don’t require much break in.

Jumpster74

iTrader: (1)

That is what I was thinking as well, but I already purchased 3 separate clutches worth of parts (ads did not list specs that rendered parts incompatible) to finally build 1 functioning clutch over a year, and I just purchased this $600 disk last month as the final piece. For principle, I think I'm just going to commit life insurance fraud if have to spend more money on even a new disk. Someone, please tell me it's savable

Luckily, I know 2 instances of individuals running the same turbo/setup with higher dyno numbers on this clutch so it holding should just be a matter of proper break-in.

Jumpster74

iTrader: (1)

I had knee surgery which kept me away from this for a bit, but following up to say that redoing the break-in procedure seemed to be no help. I then followed the "deglazing" procedure from that link, and now have zero slip at full power.

It looks like we're back in business.

patsmx5

iTrader: (16)

I used to do 7K 20-30PSI launches, slipping the clutch to 30-40 mph, on a couple different ACT clutches. They got super-glazed. Would boil the clutch fluid sometimes.

Anyways, a few days of normal driving (after it cooled down and all) and it would come back and start working normally again. Normal enough at least.

Jumpster74

iTrader: (1)

Oh hey, it's you, the devil on my shoulder.