How do kevlar clutches work with our motors?

[Backinajiffy12]

I am looking for a new clutch and since i cant afford a twin disc I heard that kevlar clutchs can hold a fair amount of hp and torque. how do you guys feel about them?

 

[Lofty]

The pressure plate is what holds most of the power. The clutch disc is just there for grabbing material. Invest in a hefty pressureplate.

 

[twicks69]

Scott, I would disagree to that statement for the main detail that you can overkill a pressure plate and cause more problems than good.

The kevlar friction material on the market is pretty decent for the ability to last a long time, have a good coefficient of friction and dissipate heat. You can also overheat a kevlar disk, and won't destroy it; it will just need to cool down and re-bed the friction surfaces, and it will be back to normal.

In your circumstance, a sprung-hub full-face kevlar disk with an ACT2600 pressure plate or South Bend Clutch (SBC) SS-X pressure plate would be a good combination for handling alot of power, as well as being able to be a good street clutch.

If you are intending on mainly racing the car, and having quite a bit of launching with little cool-down time, I would look torwards a SBC TZ/FE-Series Kevlar/Feramic dual friction full-face clutch disk, as it will handle higher temperatures and have more positive engagement for drag racing.


With that said, I ran a SBC TZ-Series kevlar full-face sprung-hub clutch disk with an ACT2600PP and it ran fine for several years with up to 600-630AWHP into the 135-139mph trap speed range at the 1/4 mile. My old clutch disk is still running strong in Mr. Peepers 11.2-second 16G car currently.

 

[Backinajiffy12]

Sweet thanks for the knowledge! I just bought a spec stage 2 kevlar clutch! Do you think I should change pressure plates?

 

[dsm-onster]

Scott, I would disagree to that statement for the main detail that you can overkill a pressure plate and cause more problems than good.

The kevlar friction material on the market is pretty decent for the ability to last a long time, have a good coefficient of friction and dissipate heat. You can also overheat a kevlar disk, and won't destroy it; it will just need to cool down and re-bed the friction surfaces, and it will be back to normal.

In your circumstance, a sprung-hub full-face kevlar disk with an ACT2600 pressure plate or South Bend Clutch (SBC) SS-X pressure plate would be a good combination for handling alot of power, as well as being able to be a good street clutch.

If you are intending on mainly racing the car, and having quite a bit of launching with little cool-down time, I would look torwards a SBC TZ/FE-Series Kevlar/Feramic dual friction full-face clutch disk, as it will handle higher temperatures and have more positive engagement for drag racing.


With that said, I ran a SBC TZ-Series kevlar full-face sprung-hub clutch disk with an ACT2600PP and it ran fine for several years with up to 600-630AWHP into the 135-139mph trap speed range at the 1/4 mile. My old clutch disk is still running strong in Mr. Peepers 11.2-second 16G car currently.

Tim, your opinion is invaluable since you've been there consistantly. What about the surrounding material? Like the springs, rivets, hub assembly. I've sheered the hub off an ACT street disk, where a good PP was used. So, which single disc has the best grip PLUS "structural integrity" for this range? . . . Kevlar of course being trump as the qualifier. I've had good longevity out of a clutchnet 6puck. But of course, time is never on the side of the frequent user

 

[twicks69]

Matt, when it comes to sprung disks, I try to stay away from ACT and SPEC, as they have been notorious for problems over the last few years with our platform. As for SBC sprung hub kevlar disks, I have not seen any problems yet.

The SBC kevlar sprung-hub disk comes in two forms normally; 4-large springs or 2-springs/4 bushings. The two forms of the hubs depends on what batch SBC receives from their manufacturer that they purchase the hubs from. Most of the time, it is the latter design, and this is the one I had the best experience with over all the years.

The full-face kevlar disk is great for street use and mild racing, whereas the kevlar/feramic dual friction disk that they make works fantastic for higher torque and high heat/abuse conditions. The feramic is a bit more aggressive than the full-face kevlar, but that is the tradeoff for handling more heat and abuse. Thankfully, it does not really affect how the clutch drives on the street, as it still is very slippable and street friendly.

Puck clutches can handle more heat and abuse, and I normally steer people away from using them in a drag-race application due to the high shockload it causes on the drivetrain. They are fine for street use or road/race or autocross where you are not doing AWD launches. As well, the puck clutches tend to wear prematurely when you put it in a stop-and-go traffic application (i.e. rush hour in Chicago, etc.), causing either pad deterioration, excessive wear on the flywheel and pressure plate, and the potential for pad delamination.

With any hub, I feel that the more HIGH-QUALITY rivets, the better. For example, the Quarter Master regular twin-disk has 8 rivets attaching the hub to the disk. In the Gear-Drive HD version, there are 12 rivets holding the gear-drive hub to the back disk, and another 12 rivets attaching the slider to the front disk.

Personally, when it comes to clutches and longevity of your drivetrain, I normally push people towards a friendly clutch that will wear out or fail before the transmission fails as it is the cheaper part to replace/repair. I went through 3 race transmissions in less than 3000 miles (if that) on my Clutchnet sprung 6-puck with a 2600 pressure plate. It just didn't like my driving style.

I feel that the disks utilizing kevlar material on the market right now are really some of the best street clutches available that have good longevity, great streetability, and when coupled with a competent pressure plate will handle quite a bit of torque before being over its capacity.

 

[SlushBoXRacer]

i had a stage 3 Clutchmasters Kevlar clutch . . . freaking loved it, I could put passes on it all night and it never slipped. . 5000rpm launches and 1.7 60 foots on Costco tires and 16 year old suspension. good times

 

[dsm-onster]

Personally, when it comes to clutches and longevity of your drivetrain, I normally push people towards a friendly clutch that will wear out or fail before the transmission fails as it is the cheaper part to replace/repair. I went through 3 race transmissions in less than 3000 miles (if that) on my Clutchnet sprung 6-puck with a 2600 pressure plate. It just didn't like my driving style.

This is what I have now. The sbr 3500 (similar to an ACT2600) with that exact disk. I havn't broken anything yet. But I have FEW launches and FEW pulls on it now. It did do very well for me for some reason slipping it for my old fwd setup which felt had decent torque (18g, then small 16g, then bolton hx35). But still nothing like the stress of aggressively launching awd frequently.

Thanks for the insite. If this tranny breaks, I will pick up immediately the clutch disk you used for 600-630hp, the SBC TZ full face kevlar. Is it possible just to get the disk if the PP is just fine? I don't see that as option on their import portino of the SBC site. . . Or is there some reason that you should use their particular pressureplates? And is the hd pressureplate like the ACT 2600 in plate load or is the ss more like it?

****Edit: Nevermind, the above questions. I finally got a chance to get to your website . . . I'm tempted to swap to that disk right now.

 

[twicks69]

!

Yeah, I explain it a bit better on my own website and the answers are pretty straight forward.

I feel that SS-series is closer to a 2100# pressure plate, and the SS-X series is closer to a 2600# pressure plate in apples-to-oranges comparison.

The clutch disk is interchangable with almost any DSM pressure plate option, and for the guys that don't know -- AWD and FWD pressure plates and clutch disks are the same for the turbo 4G63 application.

 

[turbo addict]

This seems to be turning into a Tim's clutch opinion thread; soo, what are your thoughts on a quartermaster on a daily driver??

I have a mirage turbo with a 2.0 and a e316g, I have had a ACT 2600 and fidanza aluminum flywheel that bought new in 2002, I have had zero problems with it until recently (this month). I have had 6 or 7 trannies in the car and the same clutch set up the entire time).

On my last tranny swap I noticed that the disk's 3 rivets were loose. Also my flywheel mating surface was convexly warn or warped and the clutch disk and pressure plate are warn/warped to match. I tried to cheap out and just do a new disk but the warping made that dsmcheap idea to not work.

So I have been thinking that I dont want to loose the rev-ability of the aluminum flywheel (and I have driven a friends car that has a quartermaster and really liked it). The car is fairly lightweight for a DD at 2600lb-ish.

Side note I dont really drive during rush-hour and even if I do In Omaha it really isn't that bad in the grand scheme of things.

thanks.

 

[twicks69]

!

Personally, I like running the quarter master for street use, but it is a matter of preference due to my power levels, and perception of my car being a street car.

I feel that the gear-drive disks do great for streetability, and really reduce drivetrain harmonics/decel chatter when utilized with a Fluidampr harmonic crank damper.

The twin-disk also shifts easier at high rpm, and has a substantially lower moment of inertia than a larger diameter single-disk clutch.

I had over 30,000 street miles on my first twin-disk in 2 years of use on the standard non-heat-treated hubs before exploding the hubs. I then went to a set of the heat-treated hubs with no issues, and then to the gear-drive disk assembly that I currently run.

The gear drive was by far the quietest version of the twin-disk I have ran, and decel chatter is less evident, along with being pretty smooth to engage and disengage for street use.

The Fluidampr really did help though in overall reducing engine and drivetrain harmonics. Just be sure to use longer than stock crank bolts to attach the pulley, and to use Loctite red on those bolts. As well, the Fluidampr is slightly larger in diameter than the OEM crank pulley, so you may need to replace the accessory belts to accomodate the new crank pulley.

This seems to be turning into a Tim's clutch opinion thread; soo, what are your thoughts on a quartermaster on a daily driver??

I have a mirage turbo with a 2.0 and a e316g, I have had a ACT 2600 and fidanza aluminum flywheel that bought new in 2002, I have had zero problems with it until recently (this month). I have had 6 or 7 trannies in the car and the same clutch set up the entire time).

On my last tranny swap I noticed that the disk's 3 rivets were loose. Also my flywheel mating surface was convexly warn or warped and the clutch disk and pressure plate are warn/warped to match. I tried to cheap out and just do a new disk but the warping made that dsmcheap idea to not work.

So I have been thinking that I dont want to loose the rev-ability of the aluminum flywheel (and I have driven a friends car that has a quartermaster and really liked it). The car is fairly lightweight for a DD at 2600lb-ish.

Side note I dont really drive during rush-hour and even if I do In Omaha it really isn't that bad in the grand scheme of things.

thanks.

 

[keltalon]

!

Personally, I like running the quarter master for street use, but it is a matter of preference due to my power levels, and perception of my car being a street car.

I feel that the gear-drive disks do great for streetability, and really reduce drivetrain harmonics/decel chatter when utilized with a Fluidampr harmonic crank damper.

The twin-disk also shifts easier at high rpm, and has a substantially lower moment of inertia than a larger diameter single-disk clutch.

I had over 30,000 street miles on my first twin-disk in 2 years of use on the standard non-heat-treated hubs before exploding the hubs. I then went to a set of the heat-treated hubs with no issues, and then to the gear-drive disk assembly that I currently run.

The gear drive was by far the quietest version of the twin-disk I have ran, and decel chatter is less evident, along with being pretty smooth to engage and disengage for street use.

The Fluidampr really did help though in overall reducing engine and drivetrain harmonics. Just be sure to use longer than stock crank bolts to attach the pulley, and to use Loctite red on those bolts. As well, the Fluidampr is slightly larger in diameter than the OEM crank pulley, so you may need to replace the accessory belts to accomodate the new crank pulley.

My eyes are tired for I have read just about every clutch thread on these boards since my clutch went on the track and this state hit a home run in my decision about what to run