Toyota Supra MKIV Ultimate Clutch FAQ Part 3

Picking up where we left off, time for hp/torque handling and once again, this will probably meet some resistance, but isn't that what the MKIV community is? A bunch of resisters disguised as nice people wanting to help? (wink).

HP/Torque Ratings Multi-Disc Systems

1. Tilton Quad

No clutch holds more power consistently period then the big bad Tilton clutches. Get what you pay for. 1500hp+/1200 ft.lbs + proven.

2. OS GIKEN Quad Disc

1250hp and 1000+ ft.lbs to the wheels proven in a very nice package that is half the price of the Tilton. If you aren't a hard core drag racer, you might consider this guy.

3. RPS Carbon Carbon

1200rwhp+, 1000 ft.lbs+ proven. Just a notch below the OS GIKEN, and with a little more refinement, it is pretty much a fact that carbon carbon is the way to go.

4. ACT Carbon Carbon Triple

1000rwhp+ 1000 ft.lbs on the spray proven. We don't have alot of data for drag racers, but for highway pulls and dyno-queens (isn't that a Supra thing), it does the job.

5. HKS Triple Disc

Sure it can hold 1000hp/900ft lbs, but it isn't fun on the street. Some love it, I don't.

6+. Choose most any twin disc for the standard 750hp/ car with the exception of that crazy jar your teeth loose HKS twin disc.

HP/Torque Single Discs

1. RPS Metal Militia (okay that is my name). This six puck metal disc (sprung) with a full 3200lb pressure plate and the segmented flywheel has proven to hold 900rwhp+ and 800 ft.lbs (on the go go juice). Sure, it can weld itself right to the flywheel for the slip draggers, but hey, it holds the power. I have had pucks fall off the RPS discs before, but believe that is pretty much resolved.

2. AZ Clutch. Same as a above with a differnt 6 puck design.

3. HPF Ferrite I Weld to the Pressure Plate 6 Puck. Hey, don't ever install one of these with a Fidanza flywheels, as you are guaranted to weld the puck to the flywheel by the 4th hard drag launch. Proven to 1000rwhp+ though.

4. ACT Heavy Duty, 6 Puck Metal Disc. 800rwhp/650 ft.lbs. Pretty good clutch, but once you start drag racing it hard, expect 12 passes before it starts to slip.

Chatter/Rocks in the Tin Can!! What is this? You know the sound your clutch/trans makes when your A/C is turned offand you are idling with the clutch pedal out??? Sounds like a bunch of rocks in a tin-can! To some it can be incredible embarrassing. You have $40,000 into your mods and the car sounds like a YUGO!! What causes this sound? You usually first hear this as your factory dual-mass flywheel (Google it), starts to wear out and the rubber mass starts hardening. It first starts like two rocks in a tin-can with the A/C on or off (usually off, because when you turn on A/C the rpm's raise and masks the sound).

Do aftermarket clutches have chatter? YEP! All of them?? YEP. Some are louder than others, but think this through with me. If you get rid of your factory Toyota Dual-Mass sound deadening flywheel and replace it with a hard/solid mass flywheel, then there isn't much dampening material left, so the sound reverberates out of the gearbox. These harmonics are bad for the gearbox, period, how bad, who knows for sure, but we need to hold the power, so we make trade-offs. Chatter is really the vibrating of the discs on the flywheel with engagement as it is bouncing along. That is really different then the rocks in the tin can thing, but we couple them together for the sake of conversation.

OS GIKEN is one of the quietest for the multi-discs that are affordable. Blitz Twin, quite loud, but I kinda like it. Carbon Carbons from RPS, ATS and Tilton all chatter. Hey you want a race car, you own one.

Single disc clutches need to be sprung hub on a solid flywheel or solid hub on sprung flywheel (dual mass). You have to have something to absorb the harmonics. Single disc are all loud, but I find the ACT's to be the quietest in my opinion.

Crank Walk? What is that in a MKIV Supra? Crankshaft damage caused or thought to be mainly caused by excessive pressure on the snout of the crank by heavy pressure plates. The factory pressure plate is around 2600lbs of force and to get the single disc aftermarket clutches to hold power, they crank up the pressure (various methods) to 3000-3200lbs. If you want to eliminate the fear of crank walk, then go with a multi-disc clutch, end of story.