Clutch Issues / Need help picking new clutch

[Katsu]

Hi all, hoping someone here can help a girl out,

I've been reading the thread for quite sometime and decided to post my issue. I have a 1994 NSX with upgraded headers, exhaust, mags and a few other bits here and there boosting it about 70HP higher than stock. So let me explain my issue. OEM clutch died badly in Aug. of 2011. So I decided to go with a new Exedy Hyper Clutch and replaced the bearing and slave as well. Everything was fine after and I drove the car till Nov. which it was then parked in a heated garage. I took the car out in April of 2012, for the first week I had no issues. Then suddenly out of the blue the clutch started slipping and within a week's time ( even without driving it ) my pedal became so easy to push I was pushing it to the floor with just my hand. I checked for leaks on the master and bled the system which did improve the pedal, but the car is still slipping at high revs. I took it to the guy that installed my clutch and he said the clutch was dead...after 5,000 km mind you. I would change it myself but I'm not getting my lift till next year, so it's out of the question.

Like I said this was a brand new Exedy, the car is a daily driver only during nice months and I don't dog on it all that much.

So it seems I'm stuck getting another clutch at this point and because I don't trust the first guy that installed it, a different one is doing it.

So First question, does anyone else know why my clutch might be slipping?

As for right now I'm looking at getting a new clutch, caught between an OEM ( which I don't know the HP rating for ) and a CT PG1. Anyone have thoughts on either? PG2 is just overkill for my car. Or does anyone else recommend a different clutch. I'm not going with Exedy again. I don't mind a heavy pedal either, in fact I rather prefer it due to the fact that my winter car is a Skyline GTR R32 with a Nismo clutch. It could almost be mistaken for a brake pedal until you get used to it.

Any help would be really appreciated. As of right now I'm one sad girl without her NSX till I get this fixed.:frown:

 

[RYU]

Scienceofspeed.com has their sport clutch which seems to be popular. Daliracing.com has a special price right now on the PG1 (if you're not concerned about heavy pedal pressure you might want to get this). I've picked up a Clutch Masters FX300 mentioned below but i've yet to try and is being installed this week.
http://www.nsxprime.com/forum/showpost.php?p=1572984&postcount=7

I would recommend you look into getting a clutch damper delete. Both SOS and Dali sell their version of one.

 

[Katsu]

Hi Ryu =^.^=

I actually did look into the SOS Clutch and found out it was a rebranded RPS Clutch which was made like the PG1, however from what I've read and been told the SOS clutch wears prematurely. Wish you had tried your CM, I'd be interested in knowing how it was going for you.

As for your other idea, could you explain to me what the Damper does and how it would help? Thank you so much for taking the time to reply =^.^= and hope to read what you have to say again soon.:smile:

 

[RYU]

You'll find there are relatively few clutch offerings out there for the NSX. The rebranded RPS dual disc unit was also my first choice but it's just too damn expensive.

Here is more info on the clutch damper delete. The SOS unit is a well sorted kit. Dali has their own version but not as nicely packaged though cheaper. They both work the same.

http://www.nsxprime.com/forum/showthread.php?t=161442

 

[mr_goat]

Hi,

Before getting into the trouble of replacing the clutch I would consider checking for leaks again. The clutch master does start to leak on our cars after a while. The leak is most easily found by pulling the carpet under the pedals, look for fluid there.

I would recommend replacing both the clutch master and slave (and damper delete if you want to), and rebleed, regardless of the cause of the problem. This is an easy DIY for the home mechanic.

Good luck!

EDIT: Ooops, you already did the slave. Oh well, go for the master then.

 

[RYU]

^^ agreed on getting things checked out first. Keep in mind you have a Slave Cylinder as well that is worth checking out also.

 

[tbnsxt]

Did you check your clutch fluid?

As stated above I would delete the clutch damper.

 

[Katsu]

Hi guys,

Thanks for all the advice. I have a few other questions now.

Do you think with the damper delete and the change of the master that the clutch might not slip anymore? Or should I still be looking to replace the clutch as well?

 

[kookoo4nsx]

Why not simply go back to the stock clutch? It is really ideal for applications under 300rwph which is where you are. I have the SOS 6 puck. It's grabby and took 1500 miles to break in but it holds power very well. Pedal pressure is just a little firmer than stock.

Also, there is a problem with your first post, your picture isn't loading. Try it again.

 

[mr_goat]

Hi guys,

Thanks for all the advice. I have a few other questions now.

Do you think with the damper delete and the change of the master that the clutch might not slip anymore? Or should I still be looking to replace the clutch as well?

It depends. A good way to see if there is a problem with the clutch itself is to cruise at a highway in the highest gear and then mash the throttle. There should be almost instant response. A worn out clutch will slip under these circumstances and there will be a delay between mashing and response.

A problem with the master will result in difficulties disengaging the clutch, with a pedal that loose resistance over time. This is because clutch fluid will weep through the internal gaskets when the piston pushes fluid out through the cylinder. This effect is most prominent when pushing the pedal hard and fast, more fluid will then leak than if pushed slowly.

So, if you have a problem engaging the clutch, this speaks for a worn clutch that probably was badly installed. A new clutch should last a lot more than 5000 km! If the problem is more oriented towards difficulties disengaging the clutch, do the master and fluid first, and check for other leaks aswell.

Bare in mind that it could be both problems.

Let us know how everything goes, this can be some good info for other owners having the same symtoms. Good luck!

 

[mr_goat]

Why not simply go back to the stock clutch? It is really ideal for applications under 300rwph which is where you are. I have the SOS 6 puck. It's grabby and took 1500 miles to break in but it holds power very well. Pedal pressure is just a little firmer than stock.

Also, there is a problem with your first post, your picture isn't loading. Try it again.

Stock clutch is expensive and relatively heavy. A singel disc like the SOS for example is lighter and cheaper and rated for higher torque which is good if you want to FI some day.

If I would do a clutch it would be aftermarket regardless of my engine configuration.

 

[BATMANs]

After months of research I ended up with the SOS dual carbon/carbon (RPS) clutch.

Cost was reasonable for me since it appears to be the most well rounded clutch based on the following:

1. long clutch life
2. ability to hold massive power - more than I plan for the NSX (the clutch can grow with your power mods.... none of this constant upgrade direction)
3. quietest of the multi-disc clutches (so people and passengers dun think that ur NSX is an Italian heap falling apart)
4. OEM user experience (trackable and yet can be driven on the street since the pedal pressure and engagement is about as close as it can get)

 

[TANTO]

This is a no brainer. Write off the mistake and go back to OEM. The stock clutch is good for much more HP than you have and you will once again have excellent feel and reliability. There are dozens if not hundreds who have run the stock clutch with early superchargers with great success.

Sorry, but the mods you have are good for max 30 more flywheel hp than stock, PLEASE don't trust what "tuners" tell you. Come to the list.

 

[BATMANs]

This is a no brainer. Write off the mistake and go back to OEM. The stock clutch is good for much more HP than you have and you will once again have excellent feel and reliability. There are dozens if not hundreds who have run the stock clutch with early superchargers with great success.

Sorry, but the mods you have are good for max 30 more flywheel hp than stock, PLEASE don't trust what "tuners" tell you. Come to the list.

Good point.

When I was making 430rwhp and 300rwtq I had the OEM single disc clutch (apparently one of the previous owners replaced the '93 twin disc clutch) with no slippage at all.

 

[RYU]

This is a no brainer. Write off the mistake and go back to OEM. The stock clutch is good for much more HP than you have and you will once again have excellent feel and reliability. There are dozens if not hundreds who have run the stock clutch with early superchargers with great success.

Sorry, but the mods you have are good for max 30 more flywheel hp than stock, PLEASE don't trust what "tuners" tell you. Come to the list.

I agree with this somewhat. If your drive primarily on the street the stock clutch will be fine imo.

As i've become more interested in driving my NSX to the fullest and to the best of my own ability.. i'll tell you a stock CTSC (7lbs) will cause that clutch to wear out VERY fast. I debated reinstalling my stock clutch for a while since I have a Tilton flywheel waiting for just such the assembly. At the end of the day I decided against it since I found one with lighter pedal pressure but can supposedly hold >500ft/lbs and slightly less $ than stock. We'll see...

 

[Katsu]

Ok so today I took my car out and cruised it. How it felt, well to get into 5th gear it was slipping through 3rd and 4th. I got it up to 5th and pushed it. RPM shot up, car didn't go any faster till about 2-3 secs later. See when my clutch went bad the first time, I knew it was going bad. I bought it that way, and this is exactly the same feel it had as then. I had a friend help me while I checked how far off the pedal adjustment was and well to say the least it was about 1 1/2 to close to the floor. I really think the installer killed my clutch but it's one of those parts that they can argue with you over, like brakes. So I really think at this point I'm going to get the damper delete, a new master and a new clutch.

Still unsure of which clutch though, I don't really need to drive this car to the best of my ability, it's not my track car. I have other loves in my garage that I go play with on the track. But this car has my heart and I drive it as soon as the snow melts. This is my "wanna go for a drive" car and time to go to work car during nice months, it puts a smile on my face every time I sit in it. I might go horse around with it at the abandoned track once a year but no more than that and that's primarily crazy little fun drag races.

I went with Exedy in my NSX because I thought "hey I know the clutch company" but I wasn't fond of 1st gear at all, still I would've lived with it if my clutch hadn't started to act up. The OEM clutch was smoother, but I'm also not in flat terrain. Up and down a lot of hills in one day and I do about 850km a week now on a car if not more just for work. Constantly up and down, so I'm wondering if the component of the terrain I travel should play a part in my choice.

I'm really not sure about the SOS clutch I've seen a lot of mixed reviews. However, everyone seems to like their CT PG2, but that's overkill for my car like I said. Which is why I was looking at the CT PG1. I like a clutch pedal with some weight to it, easier to press doesn't make me happy which is also why I'm shying away from the OEM a bit more. I drive with rev. matching mainly and try to never use the clutch as a brake though once in a blue moon my brain with fry and it happens.

Anymore advice you guys can add would be helpful and appreciated. =^.^=

And I'll get a pic up as soon as I get my NSX repaired, my 350z out of the Paint shop ( Orange ftw, the guy has taken 16 months...still on going, supposed to get it this friday( I hope )), my skyline's turbo gaskets fixed ( the guy has had the car for 3 months...and still hasn't taken the time to put it back together) and I get all the bits and pieces that have fallen off my RX-8 in the course of a year fixed ( including the lovely Mazda Fender Illness of OMG paint must fall off!)

It's been a rough year for my cars and all I wanted to do was have my NSX...oh well, soon soon. It really sucks when you do not have the time to do it all yourself, but I work 100+ hrs a week so this is the crap I have to deal with.

 

[Sumeronthechain]

To me, it sounds like the clutch was not adjusted properly upon installation, which caused it to not full engage, leading to the failure. However anything is possible.

I really like my SOS Sport Clutch. The only gripe I have is a little clutch chatter from a stop if I'm not paying attention. However, it always feels great on the highway or track at speed.

 

[RYU]

FWIW, I would recommend the stock clutch for you for a Clutch Masters FX200.

SOS had a special price on a OEM clutch here recently going for about $1200. That was a relative bargain.

 

[greenberet]

... I would recommend the stock clutch for you ...

14 years ago, my OEM twin disc clutch died in my naturally aspirated 3.0 liter 5-speed. During a high speed shift between 4th and 5th, one of the springs on the clutch disc itself popped out of its cage. It got jammed somewhere and after that, I couldn’t switch gears anymore. I kept driving until I got to a city, parked the car at a rest area, and had the car flatbedded to the nearest NSX-approved Honda dealer.

I did some research and found that I was not the only one who encountered that. To make sure it couldn’t happen again, I decided not to have another OEM twin disc clutch installed but went with a Comptech Powergrip instead. It has its pros and cons but most importantly, the springs on the clutch disc haven’t popped out of their cages in the past 14 years despite many more high speed shifts between 4th and 5th.

 

[RYU]

I can vouch 100% about the tired springs. its one of the main reasons I needed a new clutch. They were all rattling around and very near the point of poping out. I attributed that to my supercharger. Didn't realize any na guys had that problem.

 

[Katsu]

So green, do you like your Powergrip? Would you buy another? What are the pros and cons?

 

[L_RAO]

I am the owner of the Clutchmasters FX200 that RYU is referring too.

I changed to the FX200 when I installed my 4.23/JDM geared transmission. RYU didn't believe me when I told him that the pedal pressure was lighter than stock until he drove it.

I am very happy with my choice of clutch.

 

[EdinKali]

One other thing to check is that your clutch pedal has some free play. If the free play was not checked during the install your clutch may not be fully engaging causing slip and premature wear.

 

[angus]

I am also going to strongly recommend an OEM clutch, you will find it more than you need and will FAR outlast any aftermarket clutch you may get.

While some have expressed concern over weight, the OEM clutch assy. is lighter than most and features and aluminum pressure plate and quite a light flywheel already.

I never recommend more of a clutch than necessary because invariably the drivability/reliablity/longevity will suffer.

 

[greenberet]

So green, do you like your Powergrip? Would you buy another? What are the pros and cons?

When I first installed the Powergrip clutch in 1998 it came with a friction surface made of sintered metal pucks. That juddered pulling away from a standstill so Comptech sent me another clutch disc - a regular heavy-duty Sachs disc. That engages as smooth as butter and I think that’s what Comptech now call their Powergrip 1 clutch.

The pros of the clutch are that the engagement point is much easier to feel than with the OEM twin-disc clutch, which is kind of spongy in comparison. The damper spring cages on the Powergrip’s clutch disc seem to be a lot sturdier than the spring cages on the OEM clutch discs, so the springs shouldn’t pop out. And it has a better power handling capacity than stock.

I’m not sure whether it’s a pro or a con but the pedal feel is heavier than stock. It’s not uncomfortably heavy in my opinion and it is kind of a good match for the feel of the non-power assisted steering.

The cons of the clutch are that it doesn’t allow the engine to rev noticeably quicker than the stock twin-disc clutch does. I was hoping it would but didn’t notice any difference in that regard. The throw-out bearing is welded to the pressure plate so if that goes, it’s not easily replaced on its own. Due to the increased pedal pressure, I’ve heard that Comptech clutches can wear out the thrust bearings in the engine block if you have the clutch pedal depressed a lot. At red lights, it’s better to put the car in neutral than keep it in gear and depress the clutch.

I’d definitely consider buying a Powergrip clutch again, especially if the aluminum flywheel could be lightened so that the engine can rev quicker. It has lasted a lot longer than the OEM clutch did. A stock twin-disc clutch with a damper delete kit and a JUN or Tilton lightweight flywheel also sounds good. I’d be seriously worried about the springs popping out of the hub with that setup during high speed shifts between 4th and 5th gears, however.