New Clutch

[LotusGTR]

Guys, in a rush here so not time to search first. I have an R32 GTR (pull clutch as it has a R33 gearbox) which needs a new clutch. The car runs about 305 RWKW and currently has a single in there. I generally drive pretty gently, but the sheer torque seems to be chewing it out, I do the odd track day, but for the most part it's driven on the street. It ain't a daily, but tractability, and refinement are important to me. I'd like to avoid a mega heavy pedal, sharp take ups, rattly mutiplates etc.

I think with the power its making I'd be wasting money putting a single back in there......but the question is what to replace it with that fits the bill.

I keep reading about Jim Berry clutches? Anyhow, can the collective wisdom advise?

I'm in a rush as the gearbox is out and I need to make a quick decision as the spanerman doesn't want my jalopy in his shed for too long.

Thanks.

[axe s]

Get ahold of sliding performance or someone like that and they will tell you exactly what you need...

Easiest way and they'll be able to tell you how long and howmuch...

[benro2]

Well, I've personally spoken to Jim Berry and can vouch for his honesty and wisdom. He certainly knows his stuff and if you look around on these forums you'll see that too.

As for going single or twin, I would advise against a twin plate, especially if it's just for the road. Simply not worth the noise and driveability tradeoffs. Jim Berry said he could rebuild a stock single plater to withstand 800+hp but the downside of that is that you will need to allow for about 1-2 weeks of downtime, and it was about $1600-1800 incl. GST if I remember correctly. However, he claims it will be near stock driveability with only a slight increase in pedal pressure.

He said he could rebuild a twin-plate to withstand 1000+ hp (overkill!) but if the clutch was hard to use in the first place, he couldn't really improve it much, and it will still be noisy (but that also depends on the clutch itself too).

[LotusGTR]

Thanks. I've done that and await their reply. Would be nice to hear from some people who are not selling? Be good to get a range of responses and advice. I find it's never as simple as 'this is the answer'.

Anyone have recent personal experiences they can tell me about?

[LotusGTR]

  benro2 said:

Well, I've personally spoken to Jim Berry and can vouch for his honesty and wisdom. He certainly knows his stuff and if you look around on these forums you'll see that too.

As for going single or twin, I would advise against a twin plate, especially if it's just for the road. Simply not worth the noise and driveability tradeoffs. Jim Berry said he could rebuild a stock single plater to withstand 800+hp but the downside of that is that you will need to allow for about 1-2 weeks of downtime, and it was about $1600-1800 incl. GST if I remember correctly. However, he claims it will be near stock driveability with only a slight increase in pedal pressure.

He said he could rebuild a twin-plate to withstand 1000+ hp (overkill!) but if the clutch was hard to use in the first place, he couldn't really improve it much, and it will still be noisy (but that also depends on the clutch itself too).

Thanks for that. I do need it sharpish, so the whole re-build thing may not work for me. Interesting your commentrs about twin plates. ISC are recommending an Extreme Motorsport single plater. I wonder about the peddle pressure on that? It's supposed to be rated to 400RWKW which is a lot......

[benro2]

  LotusGTR said:

Thanks for that. I do need it sharpish, so the whole re-build thing may not work for me. Interesting your commentrs about twin plates. ISC are recommending an Extreme Motorsport single plater. I wonder about the peddle pressure on that? It's supposed to be rated to 400RWKW which is a lot......

Ohhh yeah, I just reread your original post and didn't see how you specifically wanted a smooth takeup, etc... I just happened to address that by fluke

Well in saying that, it seems that there are twin plates and there are twin plates. I've only ever driven two in my life, and they are the polar opposites of one another. The first was in a friend's R33 GTS-T and it was an Exedy with a lightened flywheel, capable of holding about 500hp. It was still a bit noisy under load under about 2000 rpm but didn't rattle much at idle. It was incredibly easy to drive. I've never actually used a stock GTS-T clutch but I'd have to say it would be suitable for a stocker. The pedal pressure was fine - quite light, good gradual takeup, and at that stage I had *very* limited manual driving experience and I managed it first go.

The second is my Supra. This is an HKS twin-plate with lightened flywheel, but there are two models of HKS twin-plates available, and unfortunately it seems that mine is the more racing oriented of the two. They are both capable of holding 650hp, but mine has an unsprung centre, no anti-rattle clips and no sequential engagement mechanism (I believe the Exedy's do also use a sequential engagement mechanism). It's still a very light pedal (about 30% lighter than a stock Supra's, or maybe 15% lighter than the GTS-T Exedy's), but the takeup length is incredibly short (like 0.5 cm) and it rattles like hell at idle and under 2000 rpm under load. Like, twice or more as loud as the exhaust, which is already very loud I would avoid something like this for a daily driver. It was my first manual car I've ever owned (and that kind threw me in the deep end) and took me a few *months* to get used to. Having said that, I really like it now, but only as a race-oriented or weekend car. I wouldn't want to use it in traffic or on many hill starts.

Oh, and obviously the more power a clutch can hold, either the harder the pedal pressure will be, or the more abruptly it will engage, or both!. Some places claim they use a magic material that sort of meets both criteria halfway, but I am yet to test these out for myself. Jim Berry says he uses "carbodic" material. I've seen a "bronze" clutch kit for the Supra from horsepowerfreaks that is supposed to retain stock pedal feel but with only a bit more increase in pedal weight, that can hold up to 800 hp. Again, I don't know how reliable these sources are - and it seems that everyone's opinions on how "hard" a clutch is to drive is different! As you can see, I've done a bit of research into this already... and just gave up... just ended up sticking it out with the twin-plater Obviously, try and stick to the minimum power (torque!) level that will manage with your engine.

Soo... after all that, I suppose you *could* live with the Exedy twin-plate, assuming there is a model for your car. You know that lightened flywheels are also supposed to rattle too, right? I suspect the kit would come with a lightened flywheel anyway so you may not be able to avoid that. But after sampling one myself, the driveability is excellent and the noise is fairly acceptable. Jim Berry and others have told me that sometimes singles that are capable of holding a lot of power can also be a big "grabby" because of the ultra frictional material you have to use - and they're apparently harder than a twin-plate to adjust just right too. They will also wear faster (as you have effectively half the surface area). Jim Berry also told me that the sequential engagement system of the Exedy's tend to wear out one plate faster, though. Seems you've got tradeoffs galore...

Edited August 12, 2008 by benro2

[LotusGTR]

Thanks for taking the time to write all that down. Unfortunately, the exec Summary is, sink $$ and time into it and see for yourself. It's such a minefield.....I think I may stock with the clutch I have and get a new clutch plate. I guess if it has lasted 18 months on this plate (it's not totally shagged) it'll last the same again with a new CP. The only concern i have is I have a track day coming up at Philip Island and I wonder how well the single will hold up under sustained throttle in some of the higher gears.........

[benro2]

  LotusGTR said:

Thanks for taking the time to write all that down. Unfortunately, the exec Summary is, sink $$ and time into it and see for yourself. It's such a minefield.....I think I may stock with the clutch I have and get a new clutch plate. I guess if it has lasted 18 months on this plate (it's not totally shagged) it'll last the same again with a new CP. The only concern i have is I have a track day coming up at Philip Island and I wonder how well the single will hold up under sustained throttle in some of the higher gears.........

No probs, although, it might be an idea to check out the Exedy website just before you make a final decision?

http://www.exedyusa.com

I know a whole new clutch is considerably more expensive than just a new plate but still... if you're going to be racing and it's slipping, that can't be good for it... or your lap times!

Well, if you don't mind a little bit of a rattle here and there, I'd have to definitely recommend the Exedy's. You can take it from me that it was *easy* to drive, because at that stage like I said, I'd driven 2 manual cars before that (a Honda Prelude and a Mazda 323) for a grand total of about 10 minutes combined, in my entire life! So if I was able to jump into this GTS-T and just drive it straight away without any thumping or stalling, it must have been pretty damn easy to drive

If you want, I can find out exactly which model clutch it was and then you can see if there's an equivalent for the GTR?

Also, are you looking for an R32 or R33 GTR clutch?

Dammit, I can't believe I've turned my original opinion about twin-plates completely the opposite way!!

[LotusGTR]

  benro2 said:

No probs, although, it might be an idea to check out the Exedy website just before you make a final decision?

http://www.exedyusa.com

I know a whole new clutch is considerably more expensive than just a new plate but still... if you're going to be racing and it's slipping, that can't be good for it... or your lap times!

Well, if you don't mind a little bit of a rattle here and there, I'd have to definitely recommend the Exedy's. You can take it from me that it was *easy* to drive, because at that stage like I said, I'd driven 2 manual cars before that (a Honda Prelude and a Mazda 323) for a grand total of about 10 minutes combined, in my entire life! So if I was able to jump into this GTS-T and just drive it straight away without any thumping or stalling, it must have been pretty damn easy to drive

If you want, I can find out exactly which model clutch it was and then you can see if there's an equivalent for the GTR?

Also, are you looking for an R32 or R33 GTR clutch?

Dammit, I can't believe I've turned my original opinion about twin-plates completely the opposite way!!

My car is a 32 GTR but the gearbox is a pull type which is more typically associated with a 33 GTR. If you can find the specs on the Exedy that'd be great. I'd reckon the GTR will be different but at least I can relate the characteristics on the clutch.

[LotusGTR]

Any other views out there? Going to have to make the just sometime today. Surely there are some clutch experts who can give me a further opinion? Perhaps comment on Benro2's comments? I reckon a single ain't going to be man enough for the job. It's a matter of getting the right twin plater, as they seem to vary. I reckon something with a sprung centre and sequential engagement.

Experts, give your opinions here!!

Cheers.

[benro2]

  LotusGTR said:

My car is a 32 GTR but the gearbox is a pull type which is more typically associated with a 33 GTR. If you can find the specs on the Exedy that'd be great. I'd reckon the GTR will be different but at least I can relate the characteristics on the clutch.

OK, well I've asked my friend and he has no idea what the model number was He did say it was a racing clutch, but that doesn't really mean anything, as everyone likes to call their clutches a "racing clutch"!

However, have a look here:

http://www.exedyusa.com/race/NM032SD

and

http://www.exedyusa.com/race/NM042SD

The first link is for the R33 GTS-T, the 2nd is for the R33 GTR, and as you can see, they are both rated for 800 ft-lbs of torque, only one is push, one is pull.

If my friend's one was indeed this model, then you'll be right. I just asked him how it compared to a stocker and he said it was actually better!

I guess all you can do now is ask a few clutch places about their opinions on that particular model.

[Boss-zilla]

From my experiance always go with the sprung centre on a road car alot better than the solid to drive. A mate had a triple plate solid centre one and when he had to take off he basicly reved it then droped the clutch and spun the wheels. Made it very had to park

[LotusGTR]

  benro2 said:

OK, well I've asked my friend and he has no idea what the model number was He did say it was a racing clutch, but that doesn't really mean anything, as everyone likes to call their clutches a "racing clutch"!

However, have a look here:

http://www.exedyusa.com/race/NM032SD

and

http://www.exedyusa.com/race/NM042SD

The first link is for the R33 GTS-T, the 2nd is for the R33 GTR, and as you can see, they are both rated for 800 ft-lbs of torque, only one is push, one is pull.

If my friend's one was indeed this model, then you'll be right. I just asked him how it compared to a stocker and he said it was actually better!

I guess all you can do now is ask a few clutch places about their opinions on that particular model.

Thanks. I've gone the replacement of the clutch plate in the existing single. It might not last forever but it's a hell of a lot cheaper than the multiplates and means I know what I'm getting. My engine builder said no matter what / which all mutlis are at least a bit of a pain in the ass, and that they are hard on gearboxes as they have no give due to their clamping forces. Reckons stripping third is a good chance with a real bitey clutch with a quick engagement. So it would seem you're potentially shagged either way with 300+ RWKW unless you go multiplate and get some OS blah blah gearbox re-build so it's bomb proof too. I guess a lot depends on how you drive and your luck too.....

Anyways, the decision has been made so thanks for your input.

[benro2]

  LotusGTR said:

Thanks. I've gone the replacement of the clutch plate in the existing single. It might not last forever but it's a hell of a lot cheaper than the multiplates and means I know what I'm getting. My engine builder said no matter what / which all mutlis are at least a bit of a pain in the ass, and that they are hard on gearboxes as they have no give due to their clamping forces. Reckons stripping third is a good chance with a real bitey clutch with a quick engagement. So it would seem you're potentially shagged either way with 300+ RWKW unless you go multiplate and get some OS blah blah gearbox re-build so it's bomb proof too. I guess a lot depends on how you drive and your luck too.....

Anyways, the decision has been made so thanks for your input.

Yeah, no probs. My friend got back to me with how much it cost - about $1300 for the clutch itself and $700 for the rod bearings (?) - or something like that. Typically about $2k from what I've seen, almost independent of the brand.

Hope mine holds up! Although mine's in a Supra - I think their gearboxes are fairly tough - and I haven't heard of anyone stripping gears in that thing, and people are putting all kinds of crazy power through them with all kinds of crazy triple plates and stuff

Hope everything goes well!

[Gtrgodzilla67]

running an exedy heavy duty, in my gtr,

340 kw for the last 2 years np yet

[Roy]

Either Berry, i have never used one but so many people pull their dicks over them then they have to be right more often then wrong. Personally, i woudl be grabbing a Nismo Super Coppermix Twin plate. I am going to use one with the new gearbox. The hold power and are so great to drive. Rock up to a Vic meeting and go for a drive with someone running one. There is at least 3 to 4 guys i know running one.

[LotusGTR]

Thanks Troy. I've gone the budget option and thrown a new clutch plate in the single and I'll cross my fingers. Where do I get info on Vic meets? When is the next one?

[BezerkR32]

the clutch plate obviously wears out, but the pressure plate is what provides the clamp, what makes you think the clutch wont slip with a new clutch plate but second hand pressure plate? i think you gave people a bum steer by asking there opinion of what clutch combination to run, you should have asked what can i do for $150, then that poor bloke wouldnt have written 3 pages out for you.

And yes a Jim Berry sprung centred ceramic will hold well over the power you are making and still be streetable.

  LotusGTR said:

Thanks Troy. I've gone the budget option and thrown a new clutch plate in the single and I'll cross my fingers. Where do I get info on Vic meets? When is the next one?

Edited August 16, 2008 by BezerkR32

[LotusGTR]

  BezerkR32 said:

the clutch plate obviously wears out, but the pressure plate is what provides the clamp, what makes you think the clutch wont slip with a new clutch plate but second hand pressure plate? i think you gave people a bum steer by asking there opinion of what clutch combination to run, you should have asked what can i do for $150, then that poor bloke wouldnt have written 3 pages out for you.

And yes a Jim Berry sprung centred ceramic will hold well over the power you are making and still be streetable.

Well yes and no. I'm not some pauper teenager (no offense, I have been there) who can't afford to do things properly. I'm well aware of the basic operation of a clutch. The current single has never slipped so i have no issue with the clamping force specifically, other than to wonder if the clutch was generally getting out of its depth. The clutch plate was worn and shown signs of having been very hot and given I'm not dumping it all the time I'd presumed was on the limit of what it could provide. Multiplate clutches (as I'm sure you're aware) have many draw backs in relation to how nice they are to use and I was not going to invest $2k into something that ultimately would give me the shits, hence canvassing opinion. I've learned there is quite a large difference of opinion on how multis are to use and also a multitude of products available. I'm happy I've made the right decision for me based on feedback from lots of people.

As for the bloke who wrote '3 pages', I'm grateful to him, but I'll assume he wanted to as it was entirely his decision to do so. Same for you, me and everyone else that craps on, on this forum. We do it because we like it.

[str00th]

If your worried about pedal pressure, get a Nismo slave cylinder, about $130-150. Doesn't brake the bank and considerable difference in pedal pressure.

if you can spend the cash, i reckon an OS Giken http://www.otomoto.com.au/osgiken/str_twin_plate.htm

You get what you pay for in the end