update: 2/4/10:
http://www.nsxprime.com/forums/showthread.php?t=132695
We installed a RPS Billet Twin Carbon Clutch last week and I had some time today to get really familiar with the clutch.
As you may remember, we introduced this clutch recently:
http://www.nsxprime.com/forums/showthread.php?t=124426
This clutch design has been in work in progress for several years now to achieve a high capacity clutch with a design that was easy to drive on both the street and the track. Clutch capacity is dictated by the clutch's clamping force and the friction coefficient of the friction liner. With too high of a clamping force, the pedal effort is undesirably heavy. With too high of a friction coefficient, the clutch engagement is very sudden and difficult to modulate in instances like taking off from a stop. Limited to what was available at the time, aftermarket clutches with high capacity in the past have had either heavy pedals, undesirable engagement, or a combination of the two.
By designing a new pressure plate from the ground up and using the latest carbon-carbon technology, RPS has been able to design a clutch that has near stock pedal effort and smooth engagement. Despite the new pressure plate and the high cost of carbon-carbon friction liners, the clutch has been designed priced similarly to the prior single disc design, and much less expensive than other high capacity clutches.
Here's a rundown of the some of the specific features:
1. carbon-on-carbon engagement: Unlike other clutches, the carbon discs engage on identical carbon friction surfaces instead of steel. This results in less warpage and greater life of the clutch not to mention smoother engagement.
2. strapless design: the pressure plate is strapless resulting in a more rugged and durable design.
3. pinned plate & balanced: the locking design of the RPS clutch results in a balanced assembly that is checked and adjusted by the factory - a race quality design.
4. organic liner on flywheel side: by using a organic surface on the flywheel side, this promotes smooth engagement for street driving.
5. by using an billet aluminum pressure plate with the floater plate guides built in, the clutch was able to be made lightweight and quieter than other floating multi plate clutches that produce a load tinny pitched rattle when the clutch is depressed.
Now, enough with the marketing pitch - what's it like to drive?
When you first sit in the car, you notice that the pedal pressure effort is very similar to stock. Perhaps 5% greater than the stock clutch - it's perfect. Now, pressing the clutch in, reach for the key and start the NSX. With the pedal than released, and the car in neutral, give a few blips of the throttle. Engine response is greatly improved from stock. The engine spins up considerably faster from the reduced weight of the light flywheel and assembly in general. This was on a early car previously equipped with the stock twin disc factory clutch. With a later model NSX, with its much heavier single disc design, the engine response will even be greater.
Now, depressing the clutch and shifting into first, you'll hear a very slight sound from the clutch with its floating midplate design. Unlike other floating multiplate clutches, I'd guess the sound is about a tenth of what others are like. The clutch was smartly built with an aluminum pressure plate with the mid plate guides built into the light pressure plate rather than the heavier steel flywheel. Because of this, the clutch is light, but also very quiet. I could not hear any noise driving down the street and slow and fast speeds.
Easing the car into gear, and releasing the clutch, you find that the engagement is smooth yet has a very positive feel. Unlike other high capacity clutches, especially the ones that curiously mesh carbon friction liners to steel, the discs do not hop as they engage which eliminates the "shudder" felt with these clutches. The clutch discs grab consistently and predictably with a more positive on feel than stock, but is easy to modulate and not much more difficult than the stock twin disc clutch. This would be much more easily driven in rush hour traffic than any other aftermarket clutch I have previously driven.
This clutch is 35-44 lbs lighter than the stock clutch (depending on year) and because of this, the clutch spins up and spins down much quicker than stock. Toe heel down shifts and rev matches can now be made very quickly, yet the clutch is not overly light like a small diameter racing clutch - so it is still easy to drive in traffic.
Overall, I'm very excited about this clutch. It's something that we've been really wanting to offer to the NSX community, especially with how many higher horsepower cars are on the market. Personally, I'm also very excited about this clutch as I'm planning on installing one into my car. I cannot think of any downsides to the clutch after driving it. I think it is a fair statement that nothing with this clutch's capacity (700 lb/ft) is anywhere nearly as drivable as this clutch is.
We did notice that due to the modular design of the clutch, it would be possible to install certain components backwards. In addition, care is needed to make sure to align the marks on the flywheel and pressure plate as the assembly is balanced from the factory. Because of this, we have produced a very thorough installation guide with photos and diagrams.
Since we have eight of these in the field now, with another ten being finish, I suspect that there will be some additional reviews soon. If you have any questions, please let us know.
For more details and more photos, please see the clutch's website here:
http://www.scienceofspeed.com/products/drivetrain_performance_products/NSX/RPS/billet_twin_carbon/
Cheers,
-- Chris
http://www.nsxprime.com/forums/showthread.php?t=132695
We installed a RPS Billet Twin Carbon Clutch last week and I had some time today to get really familiar with the clutch.
As you may remember, we introduced this clutch recently:
http://www.nsxprime.com/forums/showthread.php?t=124426
This clutch design has been in work in progress for several years now to achieve a high capacity clutch with a design that was easy to drive on both the street and the track. Clutch capacity is dictated by the clutch's clamping force and the friction coefficient of the friction liner. With too high of a clamping force, the pedal effort is undesirably heavy. With too high of a friction coefficient, the clutch engagement is very sudden and difficult to modulate in instances like taking off from a stop. Limited to what was available at the time, aftermarket clutches with high capacity in the past have had either heavy pedals, undesirable engagement, or a combination of the two.
By designing a new pressure plate from the ground up and using the latest carbon-carbon technology, RPS has been able to design a clutch that has near stock pedal effort and smooth engagement. Despite the new pressure plate and the high cost of carbon-carbon friction liners, the clutch has been designed priced similarly to the prior single disc design, and much less expensive than other high capacity clutches.
Here's a rundown of the some of the specific features:
1. carbon-on-carbon engagement: Unlike other clutches, the carbon discs engage on identical carbon friction surfaces instead of steel. This results in less warpage and greater life of the clutch not to mention smoother engagement.
2. strapless design: the pressure plate is strapless resulting in a more rugged and durable design.
3. pinned plate & balanced: the locking design of the RPS clutch results in a balanced assembly that is checked and adjusted by the factory - a race quality design.
4. organic liner on flywheel side: by using a organic surface on the flywheel side, this promotes smooth engagement for street driving.
5. by using an billet aluminum pressure plate with the floater plate guides built in, the clutch was able to be made lightweight and quieter than other floating multi plate clutches that produce a load tinny pitched rattle when the clutch is depressed.
Now, enough with the marketing pitch - what's it like to drive?
When you first sit in the car, you notice that the pedal pressure effort is very similar to stock. Perhaps 5% greater than the stock clutch - it's perfect. Now, pressing the clutch in, reach for the key and start the NSX. With the pedal than released, and the car in neutral, give a few blips of the throttle. Engine response is greatly improved from stock. The engine spins up considerably faster from the reduced weight of the light flywheel and assembly in general. This was on a early car previously equipped with the stock twin disc factory clutch. With a later model NSX, with its much heavier single disc design, the engine response will even be greater.
Now, depressing the clutch and shifting into first, you'll hear a very slight sound from the clutch with its floating midplate design. Unlike other floating multiplate clutches, I'd guess the sound is about a tenth of what others are like. The clutch was smartly built with an aluminum pressure plate with the mid plate guides built into the light pressure plate rather than the heavier steel flywheel. Because of this, the clutch is light, but also very quiet. I could not hear any noise driving down the street and slow and fast speeds.
Easing the car into gear, and releasing the clutch, you find that the engagement is smooth yet has a very positive feel. Unlike other high capacity clutches, especially the ones that curiously mesh carbon friction liners to steel, the discs do not hop as they engage which eliminates the "shudder" felt with these clutches. The clutch discs grab consistently and predictably with a more positive on feel than stock, but is easy to modulate and not much more difficult than the stock twin disc clutch. This would be much more easily driven in rush hour traffic than any other aftermarket clutch I have previously driven.
This clutch is 35-44 lbs lighter than the stock clutch (depending on year) and because of this, the clutch spins up and spins down much quicker than stock. Toe heel down shifts and rev matches can now be made very quickly, yet the clutch is not overly light like a small diameter racing clutch - so it is still easy to drive in traffic.
Overall, I'm very excited about this clutch. It's something that we've been really wanting to offer to the NSX community, especially with how many higher horsepower cars are on the market. Personally, I'm also very excited about this clutch as I'm planning on installing one into my car. I cannot think of any downsides to the clutch after driving it. I think it is a fair statement that nothing with this clutch's capacity (700 lb/ft) is anywhere nearly as drivable as this clutch is.
We did notice that due to the modular design of the clutch, it would be possible to install certain components backwards. In addition, care is needed to make sure to align the marks on the flywheel and pressure plate as the assembly is balanced from the factory. Because of this, we have produced a very thorough installation guide with photos and diagrams.
Since we have eight of these in the field now, with another ten being finish, I suspect that there will be some additional reviews soon. If you have any questions, please let us know.
For more details and more photos, please see the clutch's website here:
http://www.scienceofspeed.com/products/drivetrain_performance_products/NSX/RPS/billet_twin_carbon/
Cheers,
-- Chris
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