Twin Disc or Single Disc Clutch?

[NoClgDeg]

Hi everybody,
Has anybody converted to the single disc clutch? Is there any advantage to coverting or stay with the original setup?

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91 Red/Ivory #2061

 

[nsxtasy]

Well, for one thing, isn't the '91-96 dual disc a lot less expensive?

 

[NoClgDeg]

I think it is a little less expensive upfront but it seems that it is only good for about 30K. Of course some get more than that but that is the average.

I was thinking that if the single disc is a little more but lasts longer than it might be worth it.

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91 Red/Ivory #2061

 

[madfast]

I've heard that the nsx wears out the stock twin disc clutch so quickly and even worse after NOS or SC. Why is that? poor design? cuz twin disk should last a long time. that's why so many race cars have them. most cars that are single go to twin for reliability and holding power. anybody care to enlighten me? I think I would put an exedy one or an rps twin disk when I get my nsx

 

[nsxtasy]

Originally posted by NoClgDeg:
I think it is a little less expensive upfront but it seems that it is only good for about 30K. Of course some get more than that but that is the average.

No, 30K is definitely at the very low end. Based on what I've heard, I would estimate that the average is somewhere between 45K and 50K miles, assuming no forced induction mods.

 

[ScienceofSpeed]

I have a theory on why NSX clutches have a short life span after doing some research and talking to clutch manufactures.

The NSX has a very notchy differential. At low parking lot speeds, you can feel it engage and disengage as you get on and off the gas. I have found that drivers "compensate" for this by feathering in the clutch at low speeds. The lightweight nature of the NSX clutch setup results in even more feathering than other cars, which accelerates the wear on the discs.

I have found that the best way to clutch from a stop or low speeds is to lightly blip the throttle and quickly engage the clutch. This minimizes wear on the clutch. With time, this can be accomplished very smoothly.

When upshifting do not allow the clutch to feather between shifts. The clutch pedal action should be a smooth and quick motion. Also, rev-matching for downshifts preserves the life of the discs.

I now have 35,000 miles on my Comptech setup, and the last time it was measured, it was only worn 20% from new.

That being said, I am very happy with the Comptech Powergrip 2 setup in my car. This clutch setup is in stock.

Regards,
-- Chris

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Revolutionize your NSX with ScienceofSpeed

www.ScienceofSpeed.com | [email protected] | 877-863-4520

 

[BoneZ]

Ive got a Clutchmaster single disc clutch in my 92, and have just over 45k miles on it.

It still "feels" good as far as pressure/grip, but then again the last 10k miles have been all forced induction, so we'll see how long it holds up

As far as performance goes, the clutch was an improvement over stock for grip, and only slightly stiffer pedal pressure.

-B

 

[nsxxtreme]

Is it easy to go to the single disc in the 91-96's. Who all makes a single disc for the nsx. I haven't decided what I want to do with mine yet, it doesn't slip so I'm not replaceing it until it does.

[This message has been edited by nsxxtreme (edited 20 July 2002).]

 

[madfast]

ok let me get this clear. 91-96 have a single disk clutch and 97-2002 have twin disk right?
as far as converving clutch live. I think rev-matching and doubble clutching is the best way to conserve the clutch, not to mention tranny too. that's my .02 cents!

Dave

 

[NoClgDeg]

A question that now comes to mind is why did Honda switch from a twin disc to a single disc in 97. They could have make the twin disc clutch work with the new transmission if they wanted it to.

Also, the 91-96 NSX is the only Honda car with the twin disc and everyone else gets a single disc. Did they realize that this is a better design? Why wouldn't the Integra Type R get a twin disc or the S2000?

All the improvements they have made to the car over the years had to be done for a reason. Examples are when they reduced the toe on the back tires to get better tire life, different a/c for the environment, different gear cutting method to reduce noise, changed the diff, drive by wire, bigger brakes, chin spoiler, bigger motor, etc.

Has anybody switch to a single disc stock setup?

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91 Red/Ivory #2061

 

[NoClgDeg]

91-96 have a twin disc with a 5 speed
97-02 have a single disc with a 6 speed

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91 Red/Ivory #2061

 

[madfast]

noclgdeg,
thanks for the clarification. why would they want to go from a twin to single? I'd take a twin any day. twin last longer. Thanks buddy.

dave

 

[sjs]

Originally posted by madfast:
... cuz twin disk should last a long time. that's why so many race cars have them. most cars that are single go to twin for reliability and holding power...

Not entirely accurate. The benefit of a multi-disk clutch is their relatively small diameter, which in turn keeps weight near the center for a low MOI. Multiple disks are then necessary to get sufficient grip. That doesn't necessarily mean longer life, and could mean less given that it is more difficult to stop a rotating mass when you grab it nearer the middle. I helped a friend replace the clutch in his Ducati recently. Seven disks, but very inexpensive and very simple to replace.

As for why Acura did duals then changed to a single, I think it was a matter of doing it “right” the first time but then learning that most NSX owners are not as skilled as the Honda test drivers. Besides wearing them out I’ve also heard that many owners complained it was too difficult to take off smoothly. I’m quite satisfied with the original design and would only change it to have a bit more clamping force as with some beefed up rebuilds, but that would only make it worse for the hacks.


[This message has been edited by sjs (edited 21 July 2002).]

 

[mikec]

Deja Vou Ten years eariler for the 1987 model, Porsche replaced the twin disc clutch used in the 928 with a single disc. The twin disc clutch 928's were prone to chatter and rapid wear. The single disc clutch had smoother engagement and longer wear characteristics. Usually guys with older 928's replace the twin disc setup with a single. I don't know how it applies to the NSX, but I think its a cool coincidence.. 1987 for Porsche and 1997 for NSX.

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keep the shiny side up
MikeC 01 #46

 

[ScienceofSpeed]

I'd agree with sjs. In addition to the MOI benefits of the twin disc, the overall weight of the single disc configuration is higher than twin (35.4lbs vs 43.9lbs).

Here is a small clutch comparison, I hope to add more data points in the future: http://www.scienceofspeed.com/products/drivetrain_performance_products/NSX/default.asp

Regards,
-- Chrs

Originally posted by sjs:
Not entirely accurate. The benefit of a multi-disk clutch is their relatively small diameter, which in turn keeps weight near the center for a low MOI. Multiple disks are then necessary to get sufficient grip. That doesn't necessarily mean longer life, and could mean less given that it is more difficult to stop a rotating mass when you grab it nearer the middle. I helped a friend replace the clutch in his Ducati recently. Seven disks, but very inexpensive and very simple to replace.

As for why Acura did duals then changed to a single, I think it was a matter of doing it “right” the first time but then learning that most NSX owners are not as skilled as the Honda test drivers. Besides wearing them out I’ve also heard that many owners complained it was too difficult to take off smoothly. I’m quite satisfied with the original design and would only change it to have a bit more clamping force as with some beefed up rebuilds, but that would only make it worse for the hacks.


[This message has been edited by sjs (edited 21 July 2002).]

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Revolutionize your NSX with ScienceofSpeed
www.ScienceofSpeed.com | [email protected] | 877-863-4520

 

[robr]

and in case anyone is interested, you can easily put the newer single disc clutch in an older car, but you can not go the other way around.

- rob with a single disc in a 91, and regardless of all the discussion going on here between the two, the only difference i noticed was revs dropped faster when shifting. the double started slipping around 14,000 miles, completely died at 18,000, the single i replaced it with (which was slightly used) is still going fine at 89,000 miles.

 

[madfast]

sos,
how much torque does the exedy twin disk clutch hold? is this kit rebuildable?

 

[NoClgDeg]

Robr,
When you replaced the clutch to a single disc, what did you have to replaced? Flywheel, pressure plate, disc, etc?

How is the engagment? Where do your revs drop too on the 1>2 shift? How used were the parts when you put them in?

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91 Red/Ivory #2061

 

[ChopsJazz]

I have an OEM (does that mean it's a dual disc?) with about 50K on it. Works great every time!

 

[robr]

Originally posted by NoClgDeg:
Robr,
When you replaced the clutch to a single disc, what did you have to replaced? Flywheel, pressure plate, disc, etc?

the clutch and flywheel (they arent compatible)

How is the engagment?
same as it was before

Where do your revs drop too on the 1>2 shift?
same as before, this is a function of gearing, not the clutch.

How used were the parts when you put them in?
i think around 2k miles if i recall, the guy had a ctsc and a new clutch put in at 2000 miles so i bought his old one.

 

[ACR_Motorsports]

*********NOTICE***********

ACR Motorsports has an exclusive distribution agreement with Exedy USA
for the NSX Twin Disc Clutch. Recently, Dali Racing and Science of Speed have listed the Exedy Twin Disc clutch on their respective websites. Any units currently being purchased from Dali Racing or Science of Speed, are grey market units. Grey marketing not only hurts vendors, but also hurts you the consumer. You may get a slightly better price, but the units will not be warrantied by Exedy USA and any spare replacement clutch parts that we/ACR Motorsports have in stock will be only available to those that have purchased the clutch through us or one of our distributors. Any product install support will be only available to legitimate units. In the case of a warranty issue, you do not want to have to ship the clutch all the way back to Japan. Dali Racing/SoS, may not be aware of our exclusive agreement with Exedy USA, but its plainly clear that they have been to our website to see our product which clearly states that we have the exclusive on this clutch. We have informed and requested that both parties to delist the item and cancel any pending orders. Hopefully both vendors will live up to doing business in a ethical way. We will post a list of any vendors that continue to grey market our products. Please do not support grey market NSX products of any brand. We have spent a great deal of time effort and money bringing this product to the US and have sponsored Doug Hayashi's Flamemobile NSX during the Open Track Challenge to do testing on the clutch. We have also first hand install experience and speak with Exedy's Engineers on a regular bases. We have spent time translating the install which is not as SoS states, "identical to factory". The clutch design is unique and different from the OEM twin disk clutch, and neither Dali or SOS has first hand experience with the install. The translated manual is only available through us and our dealers. We are an ethical business and prominent members of the NSX community, including Alex Vizcarra(pres. of NSXCA), Doug Hayashi, and Factor X Motorsports have gotten their Exedy Twin Plate clutch from us. Again we hope that the NSX community does not support grey marketing any kind. The amount of Vendors that cater to our group is already small. And grey marketing will only decrease the amount of vendors serving the NSX community and discourage vendors from putting in time and money to bring new products to the US.

Keep up the standards of the NSX community!!!

Alexander

We are currently in Japan. Will be back in the office on July 29th

Originally posted by madfast:
sos,
how much torque does the exedy twin disk clutch hold? is this kit rebuildable?

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www.acrmotorsports.com

 

[ScienceofSpeed]

Apparently there is some confusion which is typical of a Japanese product coming to market in the United States.
We have been contacted and assured by the Japanese distributor that ScienceofSpeed is authorized to offer the clutch set in the United States.

Exedy has been offered in the United States for some time now, however, the NSX product is new in the United States. I have asked both ACR and the Japanese distributor to offer proof of their claims, and we have contacted Exedy in Japan and the US to provide a structured sales and distribution channel to offer this product to our US customers.

Regards,
-- Chris


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Revolutionize your NSX with ScienceofSpeed
www.ScienceofSpeed.com | [email protected] | 877-863-4520

 

[NoClgDeg]

^

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91 Red/Ivory #2061

 

[sjs]

One of my favorite topics!

Alexander.

I appreciate the information you supplied and as a consumer want to know all the facts regarding a gray market item. However, given that information I would make a decision on the facts, not to "Keep up the standards of the NSX community" whatever that means. In theory (but all too often not in practice) this is a free market system, which is one of the primary reasons that our comparatively young nation is such an economic superpower. For the most part, I personally object to the type of exclusive agreement you describe, and I disagree that it is better for the consumer. Yes, I know all the arguments used to support that position, I just feel that on balance the consumer is better served by a bit of competition. Not just in terms of prices, but also service. There is nothing more often proven in the world than the almost inevitable negative impact of a monopoly.

That doesn't mean all your hard work and great service need go to waste. If you excel in those areas then you should be rewarded by the lion's share of business. If that proves untrue, then either the product doesn't require such attention or the consumer isn't willing to pay for it. Either way, things tend to settle where they belong.

I could go on for many pages, but I'll spare you all for now.

 

[ACR_Motorsports]

SJS, this is one of my favorite topics also.

Actually the concept of free market economics is only that of a concept. Ever since the beginning of the "superpower" that is the American nation, the economy has always been mixed combination of free-market and goverment regulation. I disagree with your opinion that completely free markets are better. In completely free markets, it is natural for monopolies to form especially industries with natural barriers to entry. It is because of government laws and regulations that some monopolies have been avoided or dismantled. This being said, government regulations has also led to the granting of monopolies. However your suggestion that we have a monoply is not true. We hold a exclusive agreement for one brand of clutch for the NSX. There are many other options readily available to NSX cosnumers, so they have a choice. Given the fact that we also sell to other vendors, we are also not the only choice to purchase the Exedy Twin Plate Clutch from. So how can we be considered a monopoly?

As to you reference to the U.S being a "superpower". One of the reasons why U.S. economy is as successful as it is today because of a goverment granted "monopolies" called "patents", "trademarks", and other intellectual property rights. Without these "monopolies", economic activity, culture, and many other parts of society can not function. A free market would be one without monopolies such as "patents", "trademarks", etc. Now, how well do you think the U.S. economy be if this system all the sudden collapsed?

It is these "exclusive agreements" that have enable virtually all of global trade. In order for business to provide foreign "new products" they need a security base that enables them to exist after the introduction of the product, otherwise it would not be worth their time and money. Most American companies sell to Asia, Europe, etc based soley on "exclusive agreements".

"exclusive agreements" are barriers to protect and reward a companies efforts, risks, etc in order for them to operate and distinguish themselves. This is no different than a "consumer" that "works hard" in college to get a "degree" which serves as a barrier to higher paying jobs. How happy would you be if you went to Harvard only to find out they gave degrees to anyone who asked?

Many NSX products have been recently (2-3 years) introduced to the U.S. from Japan such as Taitec, GruppeM, etc. A lot of these products are sold under "exclusive agreements". Without these agreements, many of these products would never have been introduced or maybe quite a bit later. Isn't access to products and greater varieties of products better for the NSX consumer?

Originally posted by sjs:
One of my favorite topics!

Alexander.

In theory (but all too often not in practice) this is a free market system, which is one of the primary reasons that our comparatively young nation is such an economic superpower. For the most part, I personally object to the type of exclusive agreement you describe, and I disagree that it is better for the consumer. Yes, I know all the arguments used to support that position, I just feel that on balance the consumer is better served by a bit of competition. Not just in terms of prices, but also service. There is nothing more often proven in the world than the almost inevitable negative impact of a monopoly.

I could go on for many pages, but I'll spare you all for now.

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www.acrmotorsports.com