Stock Clutch, 425 RWHP, Still Works Fine What Am I Doing Wrong?

[Lostbuckeye]

I keep reading threads on how the stock clutch can't handle 400+ HP and the higher torque associated with it. When I installed the SOS twins on my 02 NSX it had 82K miles on the clock and it's original clutch. I was tempted to change the clutch at that time but, the clutch looked and felt great so our resident NSX guru, Scott Oliver at HNA suggested that it seems to be a waste of a good clutch to change now and he would wait. So I did. Now, with 7k more miles since the turbo install, the clutch still feels the same with no slippage at all. What am I doing wrong? I read where most everyone who has added additional HP to their car has had to change the clutch. Now, I don't track the car except for NSXPO, I don't dump the clutch at every light and I don't have my foot in the turbos continually. I tend to roll before I stomp on it. I use the added HP for acceleration when I'm already moving and not for launching and that's fine for me. I like the additional HP for that purpose and the car is a lot more fun to drive. My goal is to get to 100K before the clutch needs replaced. Is anyone else getting decent performance with the original clutch? I'd like to hear other owner's experiences.

 

[synergy004]

Driving characteristics and basically ability to drive a manual car correctly (operator error) to me. I have done the same previously without issue at 400+ on a stock clutch with similar driving habits. So what you are doing wrong is the right (on an already existing OEM clutch). In any event dumping the clutch and rolling through the gears quite harsh would wear any OEM clutch including aftermarket. You're basically playing it safe

 

[Mac Attack]

The calculated holding capacity of a clutch is rated in units of ft-lbs (or torque) when given the friction area, clamping load, and coefficient of friction of the discs). HP is therefore approximated.

The only explanation is that you aren't putting out the torque you think you are, or you are only briefly exceeding the torque capacity of the factory clutch where you don't notice it slipping before you back off. Those are the only logical explanations aside from getting a special clutch from the factory!

I make a minimum of 350 ft-lbs of torque to the wheels from 2500-8000 RPM. The stock clutch would have no chance and is why I went with a dual carbon clutch that is rated for my engine torque.

If you are happy with it for your driving style and the speed you are accustomed to, then that is the main thing. Enjoy it and start saving up for another clutch... perhaps another OEM one!

Dave

 

[BATMANs]

The clutch that came with the NSX when I bought it with 35k miles apparently was upgraded to a single disc clutch from an unknown manufacture. Dealer said it looked like the later model clutch.

At any rate it handled 320rwtq with just over 100k miles on the chassis.

I sure do miss the easier engagement of that clutch over the SOS dual carbon which is a good clutch, but like any dual disc clutch it's more an on/off as oppose to a gradual engagement. It's only the 1st gear and reverse that I have to get used to.

 

[davidf]

Wow, you have 89k on an 02. I'm glad to see it has been enjoyed.

 

[Lostbuckeye]

Wow, you have 89k on an 02. I'm glad to see it has been enjoyed.

I'm not saving it for anyone that's for sure. And it looks as good or better than an 02 with half the mileage. Thanks to a clear bra, good maintenance and a lot of cleaning. However, for the HP I've added, I guess I do drive conservatively compared to most. Plus I've had some great adventures with my son on the long trips we've taken.

 

[BATMANs]

Not driving a 02+ is like keeping your honey pot tighter for the next man....

 

[Brylek]

I'm not saving it for anyone that's for sure. And it looks as good or better than an 02 with half the mileage. Thanks to a clear bra, good maintenance and a lot of cleaning. However, for the HP I've added, I guess I do drive conservatively compared to most. Plus I've had some great adventures with my son on the long trips we've taken.

I had no idea this car had so many miles! It looks like you're good at rev matching and overall driving a manual transmission car so go put some more miles in it!

 

[docjohn]

............you are not burning enough rubber:tongue:

 

[Lostbuckeye]

............you are not burning enough rubber:tongue:

LOL! It goes through tires fast enough without that.

 

[psbnsx]

Hi, Lostbuckeye

I have a 2001 NSX with the SoS Supercharger. Dyno results show my car produces 420 RWHP and 300 lbs-ft torque. My new OEM clutch slipped after 15K miles. I am a conservative driver, with 3 or 4 track days per year. I really like the smoothness of the OEM clutch; it's the best! Right now I am using the SoS Sport 350 clutch.

At first, I thought there was something wrong with the SoS clutch because it shuddered so much in first gear. But now, after 3000 miles it doesn't shudder much. I have had to relearn how to engage the clutch without causing shuddering. Plus, I think the Sport clutch might have a "break-in" period before it becomes relatively smooth in first gear.

Next time I might go back to OEM just for the smoothness of first gear engagement

 

[ScienceofSpeed]

As a general statement, clamp force has a greater effect on torque than friction coefficient. As the disc wears out, the clamp force decreases since the lever arm of the spring becomes less effective. Thus, a clutch with 0% wear will have a much greater torque holding capacity than a clutch with 50% wear. You will probably find that as your clutch wears, it will begin to slip and will slip sooner than say an identical factory-powered car with the same amount of mileage since the torque your engine is producing is significantly higher. We have lots of customers making 400+ whp on the factory single disc clutch. Many of these customers are very happy using our Sport 350 Clutch & Flywheel once the factory clutch begins to slip since we use a factory style steel-backed organic sprung disc with excellent drivability. The increased clamp force of this clutch compared to a factory assembly increases torque capacity by more than 20%.

 

[tof]

As a general statement, clamp force has a greater effect on torque than friction coefficient.

And driving style/clutch engagement technique will have an even greater effect on torque capacity, as well as on the mileage it takes to wear the clutch friction material down with the resulting loss of torque capacity you mentioned.