Hi guys, my comments might come across biased because of my relationship with Exedy, but understand that this relationship was founded my mutual respect and not because they support me financially (because they don’t). This isn’t a sales pitch its information for helping you make the right clutch selection.
The Clutch is loud because of the design and it’s not because something is wrong with how it works. My car is a racecar so the clutch noise gets lost with all the other noises. Of course I can understand your pain, it’s like loud lost motion lifters they may not be a mechanical problem but they are still annoying and other people may think you have a rod knock.
Chatter is also part of this design and was considered when weighing the pluses and minuses. I know, I talked to the designer about it.
The NSX has a marginal hydraulic system, the master and slave has barely enough strength and distance to work the OE clutch, that’s why they need replacing so often when clutches are changed. The market already has OE strength clutches Exedy wanted a clutch that can handle the higher HP of today’s tuner market and have reasonable longevity.
Back to the hydraulics, it was designed for a dual disc system that had more holding force with less clutch spring pressure. Later Honda chose to save money and incorporate a single disk design but this application wont hold as much aftermarket HP or likely last as long. The dilemma with the aftermarket designers is working within the parameters of the OE hydraulics and why all the single disc clutches have strength and longevity issues. The other issue is pedal pressure like with the Comptech clutch, this is one of the better clutches on the market for hp but it doesn’t last long and your left leg will get bigger then your right.
Until someone engineers different hydraulics, you have three choices:
OE dual (expensive) good until you reach a certain HP and want OE clutch feel.
Aftermarket singles can be marginally stronger with more pedal pressure and may sacrifice some longevity including premature failure.
Or the dual Exedy with some chatter and noise (also expensive) but they handle more HP and last longer.
Oh, and kind of another choice the Tilton triple disk option that requires an aftermarket pedal, master and slave system. It will cost you $4000 + the clutch plates will need to be changed more often then any on the market, it truly is on/off, and I’m not sure it will handle more power then the dual Exedy.
The Cerametallic in my racecar may have some trade-offs like noise and it’s very grabby (On or off) but it was developed to meet a different need, it can handle well over 600 whp and is still the original clutch in my car since the Grand-Am races. Including myself the car has been raced by Vaughn Duarte, Pete Halsmer, Brian Bailey, Benoit Theetge and Andrie Hertanto in addition to a handful of other track drivers like Bruce McPherson. It has raced at 25 different tracks including power shifting drag races, and 4500 street miles with cannonballs and road trips. You can be sure there is no another clutch on the market that equals this clutch in an NSX for this application.
I have some new experience with the Exedy dual carbon clutch. It does not grab as bad as the Cerametallic, so it’s much better for the street (Still expensive and will still make noise), but it also handles gobs of torque, though it may not last quite as long. The trade-off is a closer to OE engagement for some of the longevity. This clutch also requires a bedding procedure like race brake pads. FactorX uses this clutch for their street, drag, and road racing… and they make more HP then I do.
Exedy just recently developed a new mid plate that will not require pre-heating the carbon clutch and will reduce the break-in. I will be testing this some time in January.
Some info about clutches-
First let me say that there is only like three clutch manufacturers in the world, so most of the aftermarket performance clutches are re-branded by one of these three. Many of the clutch brands you know are made by Exedy Global Parts. Exedy is an 8 billion dollar company that revues 1.4 billion annually mostly from OE sales. All of Nissan, all of Toyota, all US made Honda, every Ford escort ever made, GM, etc. The majority of their sales are automatic trans clutches and ranges to the racing Cadillac’s and F1 cars. Like Honda the high performance is a small sliver of their profit but they draw on a strong history of experience and learn from the track.
Carbon-
Is not created equal; it’s a relatively new technology that is not widely shared and still progressing. Exedy has developed carbon quality standards; the majority of the manufacturers making carbon plates will not pass these standards. This is the primary reason for the high cost of the Exedy carbon product.
All this said, you still need to buy the clutch that’s right for you. Budget, maintenance, risk, and application are all factors to weigh.
flyeyes said:
it occassionally kicks my shifter out of gear when I push in the clutch. But it only does this in 1st gear.
Also, it's hard to shift into gears now too. This was not a problem befoe with the OEM clutch. I have had problems with first and third gear, trying to shift into them and getting a grinding. Almost as if I hadn't fully engaged the clutch. But I had it pushed all the way in.
If anyone has some insight, I'm all ears. I planned to call Exedy first chance I get to ask them some questions as well.
It sounds like you have other trans problems; the hydraulics might solve your grinding because that’s a disengagement issue. But the popping out of gear has nothing to do with a clutch, it sounds like cable adjustment or maybe an internal problem. I would normally think engine mounts but the cable system in the NSX shouldn’t be affected unless already out of adjustment.
And no I didn't replace the slave and or master cylinder. Is that a bad thing? And how important is it that I put better motor mounts in?
