KahnBB6

iTrader: (5)

zazzn. I can't speak to the fermaic 6-puck disc you're using but I've been working with SouthBend for my setup recently using one of their *relined* from stock Aisin full face discs for the R154.

With my stock 2JZGTE with the stock twins in sequential mode (320-340hp crank or roughly 300-310whp and 315ft-lbs or possibly a bit more... I haven't been able to dyno yet) I started with the Southbend Stage 2 Daily kit (upgraded PP and a stock Aisin disc that has been relined by them with more copper fiber material) for the R154.

That began slipping for me by 800-1,000 miles almost any time I go past 3500rpm with any heavy application of the throttle. I suspect it has to do either with Toyota underrating the engine's power figures or more realistically the force with which the #2 turbo slams the clutch when it's already holding plenty of torque from turbo #1 at full boil. Maybe this is a sequential twin quirk? I'm not sure but SouthBend rates their MKIII clutches based off the 7MGTE's staged power upgrades and both engines (and 1JZGTE's) express their torque delivery differently.

The SouthBend Stage 2 Daily R154/MKIII Turbo clutch kit is rated by them conservatively at 365 ft-lbs, meaning they expect it to handle a little bit more than that.

Anyway, I now have SouthBend's R154/MKIII Stage 3 Daily kit (this pressure plate has more clamping force than the last one but uses the same disc as before for longevity) which is conservatively rated at 395 ft-lbs.

When I finally have it in and past break in I can report back on how it holds up. I'm not going to go beyond stock boost (10-12psi) with this setup. At such low boost I'm looking for long clutch life in a mostly daily driven SC rather than big power holding in a weekend or occasionally driven car.

For much bigger power holding this wouldn't cut it. SouthBend makes a Stage 4 pressure plate as well and their full face Endurance discs and pucks will hold more power but I think they're all intended for less mileage than a milder daily clutch setup like mine.

Still, I was very surprised that I'd need a Stage 3 SB pressure plate just to reliably hold stock 2JZGTE sequential boost past 3500rpm.

I've used ACT kits in the past but I'm not convinced they're the best out there. I never got great mileage from them either. Driftmotion has their Action Clutch kits but I have no idea how they stack up.

There are always going to be tradeoffs with traditional R154 clutch kits to hold big power. OG Giken or Exedy twin discs with the movement change kits (to avoid crankwalk) are the best ones, though very pricey of course :/

If I were to turn up the boost on my setup to go from 340hp(ish)/325ft-lbs(ish) up to 400-450whp and 400+ ft-lbs I'd have to change my setup yet again, probably to a SB Stage 4 kit. And then I would get concerned about crankwalk and I'd probably look into an OS Giken twin disc with the movement change. But I tend to go a bit overkill in eliminating potential issues.

For what it's worth though I hope this helps a bit.

lexforlife

iTrader: (7)

South bend stage 3.5 endurance here for me . Holds 600ft lbs and 750rwhp easily. I used to use exedy twin disk and that started slipping within a year of abuse... love the feel of the south bend as its as soft as stock

KahnBB6

iTrader: (5)

lexforlife, how many miles do you have on that SB Stage 3.5 kit so far? And what whp and torque is your engine throwing at it?

stockhatch

iTrader: (12)

Wow, I haven't been on here in forever, but what I ended up doing was sending the stock PP back to SB and had them re-spring it for 400ft-lbs. I ran that, and the feramic street disk, making 465whp, and a little over 400ft-lbs. It was RIGHT at the bleeding edge, but I abused it for over a year, sold the car, and the new owner DID eventually put a new clutch in it. Long story short, the torque ratings from SB are pretty much on the money from my experience. Just call them and explain what you want, and they should be able to build something for you

KahnBB6

iTrader: (5)

Thanks for the update, stockhatch! Since I last posted here I have been running the Southbend Stage 3 "Daily" (full face organic) clutch in my car. It was Southbend's suggestion that I run the "Daily" clutch disc rather than the "Endurance" clutch disc. However in practice I have found that I usually get slippage if I accelerate too quickly from a stop or stay more than 2-4 seconds into the transition to my second turbo (stock sequential twins).

I'm at the stock 10-12psi boost setting on my turbos and I know I cannot actually be outputting 400 ft-lbs of torque from a stock 2JZ-GTE. Maybe it has to do with SB's copper lined full face organic disc not being able to absorb the sustained heat generated by one surge of torque right after another. Not sure honestly.

Normal driving is fine. Spirited driving is fine. I just don't feel that I can go all out with this clutch despite it being rated for far more torque than the engine is supposed to put out. Even if its actual crank torque is closer to 360 ft-lbs in stock form that should not be enough to overwhelm a SB Stage 3 Daily kit's 395tq rating under hard driving. And yes, I religiously followed their 750mi break-in instructions and actually extended that babying to 1000mi before gradually, successively pushing the clutch with my modest boost level.

As far as pedal feel I have no complaints. And at this amount of clamp load from SB it appears that the stock V160 clutch's clamp load rating is only being approached rather than surpassed. However they get their torque ratings locked in they're supposedly still being kinder to the rear crank thrust bearings than other aftermarket clutches tend to be, although I still keep my neutral safety switch disabled and always start up by checking the shifter with no clutch pedal depression just to be safe.

I'm now looking at getting an OS Giken STR2CD twin plate clutch with their movement change kit.

stockhatch, what are you driving now since you've sold your SC? I see a Falcon Ute in your sig. You've imported one? It's good to hear from you!