How strong is our stock clutch?

[Rovert]

I just tried something yesterday that I didn't mean to try...LOL. I guess I was a bit slow but let me tell you my story:

For years now if I need an aggressive start from stop I can easily launch at 2,000 no problem. Then I got up to 2,500, and upwards to 3,000. I found 3,000 is a good number for my sticky 265's because I want just enough that I could break rubber loose for a split second.

Anyways yesterday I wanted some fun so at a highway light I was all ready for it to turn green so I could get out of the stop box quickly. :roundel Light turned green, I went WOT, just as 3,000 neared I aggressively squeezed the clutch out as I always do so there is barely any slip but enough that I don't shock the mounts. Well I was too slow...... nono As the clutch came out the RPMs were at 5,000. I thought OK, the RPMs will go back down as the clutch grabbed. The car shot out like a rocket and the RPMs hardly went down as the clutch was fully engaged. At 5,000 I'm expecting that extra energy would have been dissipated into tire spin. But I didn't get any and I had ASC+T off. The RPMs never went below 4,500 as I approached the top of 1st gear which then I redlined. :confused It sounded like a CVT transmission at WOT.

Right away I clutched in to goto 2nd gear nicely and kept accelerating. So now in my head I thought, "OH CRAP". Not more than 5 seconds I smelt the clutch which I haven't experienced in years of owning my car. It was really minor though. When I learned on hills as a newb standard driver, I smelt the clutch much more than this shenanigan. So I dropped it into 5th and 6th to goto WOT to test if all the sudden I have clutch slippage but it was rock solid.

Is my clutch showing signs of wear or is it just not strong enough to hook up at such high RPM? I didn't mean to do it but it was an interesting experience. I'm sure noone really does standing 5,000 launches. Haha. I do hear that people will upgraded engine power need more powerful clutches and I'm assuming just so it can handle that extra torque so the clutch doesn't slip on itself under high torque acceleration.

:begging

So what the heck happened if my common sense didn't spell it out correctly?

[Lespaulman16]

When you went from clutch disengage to instant clutch engage, especially at WOT, you subjected your clutch disc to some serious friction, and therefore, serious heat. What you smelled was the result of this heat.

As far as damage is concerned, I wouldn't make it a habit, but what you did yesterday did nothing in the overall scheme of things.

[Ryans323i]

^^^Boom! Glad to have you around already!

[ryankokesh]

+1

[nike001]

Your clutch isn't showing wear. You just slipped the balls out of it.

Not a big problem. Slipping under WOT or in high gears when you're NOT working the clutch is when you should be worried.

[Rovert]

Oh good....my tranny has been super strong thus far. I'm just clocking in at 159,000 miles on the original clutch and this has been one handful of times where it's slipped this much. I've gone WOT to engage right at 3,000 and it's perfect. The clutch grabs 100% when I want it to and I go into mini warp speed with a tad of tire chatter at the beginning.

But noone really answered the question about how strong the stock E46 clutch is. Would every non-M clutch slip at a 5,000RPM launch? Is there just too much rotational energy for the clutch to grab?

[BRGcoopahS]

I'd say its pretty strong if you're at 159k on the stock clutch and it grabs perfectly.

[Lespaulman16]

Oh good....my tranny has been super strong thus far. I'm just clocking in at 159,000 miles on the original clutch and this has been one handful of times where it's slipped this much. I've gone WOT to engage right at 3,000 and it's perfect. The clutch grabs 100% when I want it to and I go into mini warp speed with a tad of tire chatter at the beginning.

But noone really answered the question about how strong the stock E46 clutch is. Would every non-M clutch slip at a 5,000RPM launch? Is there just too much rotational energy for the clutch to grab?

Doing research. Post back up laterz

[ryankokesh]

Research?
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSU4gU_J4BnJOhTetb0f-Os3fFBFRg0OswJhslHE1fdg-GTb11NNQ


or reeeesearch?
https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcRZW50pBEzulhvOF0_b-a6GsvXiX4ftOfooKtO5TLUm7xSUsetw

[Lespaulman16]

reeeesearch
http://cdn.speednik.com/files/2011/10/Screen-shot-2011-10-30-at-11.31.40-AM.jpg

[BRGcoopahS]

Haha. Vid or it didn't happen.

[Ryans323i]

:rofl

[alexandre]

LOL @ thread

[Torxuvin]

http://www.michelinalley.com/wp-content/uploads/RD2_4510-2.jpg

[midlandtech]

Haha pics mad me laugh... Mine grabs hard at 3-3500 but its new as of 90k miles I think your good too many factors like tires, road conditions etc to consider regarding a slipping clutch or spinning tires


~Steve
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[az3579]

You'll be fine. It probably slipped a little in 2nd due to the heat that was still in the disc; it was probably slightly overheated at the time. If it's fine now, then there was no damage.

[Rovert]

I checked it immediately when I did a slower shift to 2nd. I engaged at a revmatch and mashed it just to make sure...it didn't slip so I kept hauling. LOL. But once I got up to speed I put the tranny into neutral and just let it cool off on it's own without it being pancaked to the flywheel. Thought that was the least I could do!

[az3579]

I checked it immediately when I did a slower shift to 2nd. I engaged at a revmatch and mashed it just to make sure...it didn't slip so I kept hauling. LOL. But once I got up to speed I put the tranny into neutral and just let it cool off on it's own without it being pancaked to the flywheel. Thought that was the least I could do!

The pedal disengages the clutch. If your foot is off the pedal, the clutch is engaged. If your foot is on, the clutch is disengaged.


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[nike001]

But noone really answered the question about how strong the stock E46 clutch is. Would every non-M clutch slip at a 5,000RPM launch? Is there just too much rotational energy for the clutch to grab?

Your question is too vague to answer, that's why.

It depends on how much gas your giving it, and how fast/slow you're letting the clutch out.

If you go WOT until 5,000RPMs then dump the clutch, I don't see any reason why your clutch should slip. But if you're doing that on a constant basis, I'd be more concerned with drivetrain components than clutch wear. Dumping the clutch is said to be better overall for it than slipping it to launch/start.

[Rovert]

I don't think I've ever just let go of the clutch. I've always thought that to be too "shocking" for the mounts. So I went easy on it and engaged the clutch within half a second max. I don't do 3K launches often but when I need to I'm not shy about it if I want me car to hop out like a bunny with it's tail on fire. LOL. With slippage, what parts of the drivetrain gets worked over? I always thought it was just a little extra heat on the clutch and flywheel.

az, if a clutch is engaged when the pedal is out...what is it engaged to when the transmission is set to neutral?

[Nivo]

You probably put good heat to the disc/pressure plate.

[Sockethead]

Kpro's 135 has a stock clutch and that has over 400 HP at the rear wheels. The owner of Bimmerwerks has a 335 in full race form and is also using a stock clutch. He told me that the e46 stock clutch is plenty strong to handle most anything..

[Rovert]

So then if my clutch slipped like crazy at a hardcore WOT 5,000RPM engagement point....that means it's not as tight as it should be. Guess one day it'll go out. But for now I'm going to make it last past 200,000 miles.

[Sockethead]

heh, if it didn't slip, you'd probably be picking up axle peices or something... dumping the clutch at 5000 rpms isn't something you want to make a habit of, y'know?
If you really want to test it, you can always side-step it but last car I did that in, I sheared the axle right off... that was drag racing an old muscle car on a track.... no one's dumping the clutch like that in road racing where most most BMWs live

[Crickett]

az, if a clutch is engaged when the pedal is out...what is it engaged to when the transmission is set to neutral?

The clutch is still engaged / pressed against the flywheel, even if the transmission is in neutral. Pressing the clutch pedal disengages the clutch from the flywheel, effectively disconnecting the engine from the transmission. Putting the transmission in neutral effectively disconnects the transmission from the driveshaft. So, clutch pedal out & transmission in neutral is engine connected to transmission (via clutch) & transmission disconnected from driveshaft. HTH :thumbsup

[az3579]

The clutch is still engaged / pressed against the flywheel, even if the transmission is in neutral. Pressing the clutch pedal disengages the clutch from the flywheel, effectively disconnecting the engine from the transmission. Putting the transmission in neutral effectively disconnects the transmission from the driveshaft. So, clutch pedal out & transmission in neutral is engine connected to transmission (via clutch) & transmission disconnected from driveshaft. HTH :thumbsup

This is what I was going to say but didn't get a chance to type out. Thanks for the assist. :)


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[Sockethead]

Interetsing useless fact:
Big trucks have a clutch brake in there too. When you press the clutch in all the way, it engages the brake. The reason this is needed is that the gears in the transmission of those trucks are so heavy that when the trans is in neutral and the cluctch engaged, then the clutch is disangaged the inertia keeps the gears spinning making it almost impossible to get in gear without the clutch brake to stop them from spinning...

[Rovert]

Wow thanks for the info. :D

Rob I don't normally dump anything that high. It was just by fluke I did it. I just always though if I am launching to get off the line quickly....if there is no tire slip dissipation, there is a lot of energy being built up somewhere else. I don't want to give my tranny the case of blue b@lls. Am I allowed to say that? LOL

[BimmerWill]

Kpro's 135 has a stock clutch and that has over 400 HP at the rear wheels. The owner of Bimmerwerks has a 335 in full race form and is also using a stock clutch. He told me that the e46 stock clutch is plenty strong to handle most anything..

Wow...any idea what mods are on kpros 135?

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[Sockethead]

Wow...any idea what mods are on kpros 135?
Yea, there are a lot. The engine and injectors are stock. it's got an aftermarket charge pipe, intercooler, blow off valve and intake. It has catless downpipes. aftermarket mid pipe and Corsa exhaust The tune is a Burger Motorsports Jiuce Box.
There are a bunch of suspension and appearance mods too but I don't want to hijack this thread. :biggrin

[Rovert]

It doesn't matter what mods are on it. It's too illegal for the street! Rob showed me. It's too illegally quick!!!! Don't show the mods...the cops will shut down the companies who make them! Keep it secret!!!! I was even fast asleep after a long late night of being up at their house and I was awakened by the sweet sound of the 135i. Didn't need an alarm clock. LOL. It's too illegal for anything!!!

[Sockethead]

It doesn't matter what mods are on it. It's too illegal for the street! Rob showed me. It's too illegally quick!!!! Don't show the mods...the cops will shut down the companies who make them! Keep it secret!!!! I was even fast asleep after a long late night of being up at their house and I was awakened by the sweet sound of the 135i. Didn't need an alarm clock. LOL. It's too illegal for anything!!!

:facepalm