Tuned N54 clutch problem?

[acivick]

Saw this over on the Z forums:
http://e89.zpost.com/forums/showthread.php?t=331749

Quote:
"With the release of the Z4 35is BMW will be offering only one transmission; the DCT. Our offering only one transmission; the DCT. Our understanding is that the manual 6 speed Z4(specifically the clutch) can’t handle the torque that comes with the engine upgrade in the car."

Never thought about extra torque taking out the clutch, but it makes sense. I guess I should fix that CDV sooner rather than later.

[amdmaxx]

If you upgrade power, clutch should be strengthened as well generally..
But I didn't hear of too many ruined clutched due to power upgrades..

[acivick]

Well, I do assume there's a certain factor of safety, say 20%. Still, haven't seen it commented on much, probably since not many people would be near 70-100k miles in a 1er yet. Just something else to think about if you are going to drop one of those JB3s in.

[BlackFlash]

You mean 70k-100k miles before the clutch eats it? How much would a new clutch cost?

I am confused by this issue as well. I started another thread asking if the only people running jb3 had autos. Funny you haven't heard of anyone complaining about clutch failure yet, but perhaps, as you say, people just haven't accumulated the miles.

[acivick]

Rule of thumb is generally 100k to 200k miles, depending on the car, the driver, and how they treat it. No one but the driver will know for sure (abnormal tach readings when shifting and such). Cost is probably in the $1-2k range.

[escobar929]

clutches are part of the service, at least it was w/ the mini's, so who cares, just take off the jb3 before going in

[imported_mega]

I doubt many will go in for clutch service before the free service warranty is expired

[jeremyc74]

Originally Posted by acivick

Cost is probably in the $1-2k range.

That's too high. You're looking at about $500 in parts at the most, and probably $250 in labor. An experienced tech can change a clutch in under 4 hours.


Here's an upgraded aftermarket clutch for $600.

http://www.vividracing.com/catalog/c...7-p-60128.html

I've got nearly 40k miles on my car, and I've had a tune on it since about 3k. I ran an SSTT until about the 10k mile mark, and I've had a JB3 on it since then. My clutch is still working fine, but it doesn't feel quiet as good as it used to. The factory clutch has enough spring force to deal with the power from modified cars without slipping, so that shouldn't reduce its life by itself. Launching the car or making hard shifts under power is what really destroys the clutch, and the more power you have the more damage you do each time.

I think if they're driven normally the JB3 cars won't see a significantly shorter clutch life than stock vehicles, but if they're driven hard, the difference will become noticable.

[acivick]

Labor around these parts is in the $150-200/hr range, at least if you bring it to a decent shop. Obviously YMMV, depending on location.

[jeremyc74]

Originally Posted by acivick

Labor around these parts is in the $150-200/hr range, at least if you bring it to a decent shop. Obviously YMMV, depending on location.

That's double the standard rate. If that's true, I'd move.

[BlackFlash]

If the only concern with the 6mt is a $1000 clutch replacement every 5 years, then that's no concern at all.

[acivick]

Originally Posted by jeremyc74

That's double the standard rate. If that's true, I'd move.

Jersey: home of insane labor costs, auto insurance, and taxes.

[onefastman]

My clutch went out on my MT car. Did not need a fly wheel or anything but just parts and labor was $1500, thankfully it was covered under warranty. Had I needed a flywheel and all that stuff, it would have been around $3500, check around and you will find a horror story or two. The reason they will not is if there are hotspots on the fly wheel and/or your clutch is shredded. I had 8K miles on mine...

[akak1997]

if I need to replace the clutch, I'd just upgrade to a lightweight flywheel as well.

[jeremyc74]

Originally Posted by onefastman

My clutch went out on my MT car. Did not need a fly wheel or anything but just parts and labor was $1500, thankfully it was covered under warranty. Had I needed a flywheel and all that stuff, it would have been around $3500, check around and you will find a horror story or two. The reason they will not is if there are hotspots on the fly wheel and/or your clutch is shredded. I had 8K miles on mine...

$3500 for a clutch replacement is insane.

[onefastman]

Welcome to the world of bmw... I had to do a clutch, syncros on a 3 gears and some other transmission work on my 85 911 when the clutch went and it cost about 2500. Bmw sucks in this respect.

[imported_mega]

Originally Posted by onefastman

Welcome to the world of bmw... I had to do a clutch, syncros on a 3 gears and some other transmission work on my 85 911 when the clutch went and it cost about 2500. Bmw sucks in this respect.

that's a hell of a lot more work than a clutch, a clutch is basically external to the transmission

for syncro's and gears they have to open up the transmission, it does not matter what brand you have, that kinda work is expensive

[jeremyc74]

Originally Posted by onefastman

Welcome to the world of bmw... I had to do a clutch, syncros on a 3 gears and some other transmission work on my 85 911 when the clutch went and it cost about 2500. Bmw sucks in this respect.

They could "suck it" if they quoted me $3500 to replace a clutch.

The total OEM parts cost for this repair is around $450. The flywheel can almost always be resurfaced. They're screwing people if they're charging anything close to $3500. You can do an automatic transmission overhaul for that kind of money!

http://www.realoem.com/bmw/showparts...27&hg=21&fg=05

[jeremyc74]

Originally Posted by imported_mega

that's a hell of a lot more work than a clutch, a clutch is basically external to the transmission

I think his point was that a more extensive repair was less expensive, even on a Porsche.

[AntonV]

Hopefully, when we reach that point, there will be a lightweight flywheel that has a few years of testing. The exhaust will be down, and the tranny opened up. Might as well throw some better stuff in there.

Had the aa flywheel with ///m3 clutch in my e36 328is. It was a fantastic mod for the money.

[onefastman]

One can hope..

[bulldog_yyc]

Originally Posted by jeremyc74

They could "suck it" if they quoted me $3500 to replace a clutch.

The total OEM parts cost for this repair is around $450. The flywheel can almost always be resurfaced. They're screwing people if they're charging anything close to $3500. You can do an automatic transmission overhaul for that kind of money!

http://www.realoem.com/bmw/showparts...27&hg=21&fg=05

the flywheel is not supposed to be resurfaced and its a ~$1200 part, which will push the job close to the $2500 - $3000 zone for full clutch and flywheel