OK I ahve the ACT street clutch installed. It is much better than the stock one, but I have a question I just recently got on the clutch hard slipping it a little off the line, maybe a little too much, I got the funky clutch smell again, it went away quickly not like the stock one but I was wondering is this normal for an after market clutch that can hold 400 hp supposedly. I know I didnt slip it that much, at least I didnt think I did, no tenough to make it smell but it did. I broke the clutch in easy too, and it has like 1500 miles on it now. Any input is appreciated.

Thanks,
Eric

 

what no one has anything to add to this??

 

If you slipped it and smelt it burning, then you are slipping the clutch too much. Any clutch will burn if you slip it too much. Unless you have something trick like a carbon disc, then this is true for all clutches.

 

Yeah, it sounds like you slipped it really hard. It should be fine though. Do you still have the stock restrictor?

It's better to drop the clutch a little faster and let the power of the engine carry you out of the hole. A good clutch will take the power without a problem, but you have to be a little careful how much heat you put through it. Example (don't try this at home): Dump the clutch at 7000 rpm and the clutch won't complain a bit (everything else might complain), but slowly slip the clutch out of the hole at 4000 rpm with your foot mashed on the throttle and the clutch may scream for mercy. Somewhere in the middle you will find the technique that the whole car is happy with. Feel free to email me if you have any other questions.

 

Yes Actman I still ahve the stock restrictor in the clutch. Why does this matter? Should I remove it?

thanks,
Eric

 

The restrictor will keep the clutch (dis)engagement closer to the 4000 RPM scenario Dirk mentioned.

 

Yes, it matters bigtime. Do I recommend removing it?? I don't like to recommend anything that will jeopordize your drivetrain or warranty without knowing how responsible you are, so it's really your call. That being said, if it were my car, the restrictor would be gone. I have said it before (and will probably say it again) that I am not afraid to take the responsibility if I stupidly dump the clutch at 8000 rpm on four slicks WOT and blow things up. I am not the kind that will come crying to Mitsu. about the parts left on the ground if I decide to do something stupid like that. What the restictor does is leave you no control to allow the clutch to engage faster than a certain rate, which is too slow for aggressive driving without possibly overheating the clutch.

 

Hey Dirk, I just want to commend you for your prolific participation in this forum and your honesty, even being forthright about the limitations of your own product. That builds trust amongst those that know that there is no perfect product and one of the challenges of engineering is balancing the tradeoffs. I personally favor some of the tradeoffs you've made. One thing I'd like to ask is how long do you think your clutches will last given normal use and decent driver skills. I know there is no warranty on wear items like clutches, so I'm not holding you to it from any legal liability standpoint. But I was wondering what you felt like would be swag ballpark estimates for ACT clutch life. If you don't feel comfortable discussing this in an open forum, I would understand, and maybe you could email me (youngjun91@yahoo.com) if that were the case.

But I am surprised when people talk about their aftermarket clutches that should last a good 30,000 miles. That's it?! What's up with that?! I haven't worn either of my clutches in the two sports cars I've owned (Starion / Integra GSR) and they were/are at 130K and 152K miles. Granted they were not AWD and didn't have the horsepower like the Evo, but I definitely don't want to be replacing my clutch 5 times during my ownership. Is it just the nature of the beast (the Evo)? Am I entering into the modern car world where multiple clutch replacements come with the territory of owning any 300ish horsepower car be it a 350Z, M3, S4, STI, whatever?

 

Ummm ACT cluch is smelling sound like a good launch to me. I slip the hellout of my ACT 2600 with a street disk on my GSX (485whp) pass after pass after pass. That thing just does not give up. If it is smelling then it is grabbin. I have had 3 ACT clutches in the GSX now for the last 6 years. I loved the grip and the feel of them.

 

Did the same thing players234, and wondered too. It seems fine though. Thanks for info Actman. Great questions/responses. Really, helpful. Dumping the clutch, at my 2nd time at strip got best 60', and felt fine. But, what technique is gonna get best 1/4 results. Combination slip/dump or just drop it, to be up on boost and get best momentum in the quarter. really liking the ACT clutch BTW.

 

It's difficult to answer how long it will last, but I don't mind answering publicly. Just look at the variety of answers on this forum alone regarding the stock clutch. Judging by my impression of your driving, prayer, careful calculations, measurements of which way the wind is blowing, wild guesses and assumptions, your ACT clutch will last exactly 132,326.59 miles. What can I say? I couldn't resist the tempation. I get more sarcastic on Fridays.

Fuel for thought: Our clutch has what it takes to make the clutch last longer and hold more power. Since we change to a stronger spring, the clamp load is increased AND the working range is broadened (more clamp load over more distance). The tradeoff of course is pedal effort. For the clutches that have a light pedal but have increased clamp load, they trade off clutch life (at least in the pressure plate design) because of the change in geometry. The friction material we use on our street disc has proven very durable and long lasting. It is the same material used from the factory on some high output cars like Viper, Corvette and 911 Turbo. We have guys running 10's, 9's and even 8's (John Shepherd) using this material. As the lilgsx posted about smelling the clutch (GSX which is quite smaller) the clutches hold up to a suprising amount of abuse.

Any friction material has it's limits in regards to heat or abuse though. Once you overheat the material's resin, it will lose a layer of material (just plain melts off) which can shorten the clutch life considerably. If you are constantly abusing the material, it may not last very long, to put it simply. I think this is the case with the stock EVO clutch. The material is not resistant enough to heat and the restrictor is forcing the clutch to slip under hard take offs. What is interesting to me is that the stock STI clutch is basically the same clamp load and the same friction material, but I don't hear that they are wearing out rapidly like the stock EVO.

 

From reading their forums, I've noticed the same thing too. I wonder what we're missing.

That's cool, gotta love the quoting feature in the forum software . Seriously though, do you think that the clutch THEORETICALLY has the capability to last 100K+ miles?

 

1. I think it is a combination of things: restrictor resticting too much, possibly higher first gear, light stock flywheel, high engagement point, and vague mushy feel (long rubber line). All of these things make for more slippage, therefore more heat and wear on the clutch.

2. There is no way to give you an honest THEORETICAL answer. Just like with the stock clutches, there are too many variables. Just driving style and type of driving makes huge differences. If you drive on the freeway most of time (even driving like a mad man) your clutch will last a few times longer than if you drive city streets traffic every day. All I can say is that the clutch should last much longer than stock, especially if driven hard. The stock clutch doesn't seem to last when driven hard.

 

With this in mind, I've been eyeing your pressure plate with RRE's "upgraded disc". In their package, they claim better heat handling from that combination. Now I know who you work for and who you don't, but have you any feed back on the RRE disc with your pressure plate? From the research I've done, it seems the hot ticket for the "hot foot" daily driver. Will ACT ever offer such a disc?

 

Our disc is "upgraded" by using steel backed linings, proven performance friction material and less marcel (cushioning between the linings). What makes the RRE disc more beneficial in your opinion? If it's the friction material I think it is, it has good old asbestos, and I have heard pretty good feedback, but it's not some special magic formula. I guess I don't follow your reasoning. Are they claiming better heat capacity than our parts, or just stock parts?