Clutch choices for 350-400HP !!
 

What's the best clutch choice for Track Miata with 350-400HP and 6 speed transmission. The car has built 1.8 and EFR6758. Any input is appreciated.

How much torque? Will you street drive? Does your trailer have a winch?

The car is still registered so don't mind taking it out for some fun driving. Yes My trailer does have a winch but even my other race car with more power is not that crazy and I'm still able to drive it up. I'm not sure about the torque since haven't finished the setup so it's not running yet. The car is going to be 85% track duty.

The 949 twin disk would be the no compromise racing clutch. Easily able to take what you're dishing out and its the lightest setup going, but I wouldnt want to get stuck in traffic with it or drive the car onto the trailer with one. The more street mannered option that adds a couple pounds would be the speedsport, its rated to 300ftlbs but goodwin claims to be running 350ftlbs though it on their shop car. Super easy to drive, engages so nice, very easy to launch. Or there's the normal choices everyone else makes that arent as light as the 949 or speedsport and arent as easy to drive as the speed sport but are cheaper and more common.

Why not? I have the organic twin-disc and it is was okay on the street and just fine getting onto the trailer. Have you driven one? Maybe the ceramic is not as nice, I haven't driven one of those.

robert

I've got the FM2 currently and if drives beautifully in traffic...only slightly stiffer then the factory MSM clutch.

Would probably do the trick well for your torque levels...I'd upgrade to the twin disk if ever given the option though...and the monies.

I drove an organic twin disk. Wasn't easy to negotiate the paddock, wasnt easy to modulate on the launch. Its on a N/A auto-x car, owner seems to be on a once a year replacement cycle for the discs with most of the wear coming from driving the car onto the trailer. The ceramic would really be required for the OPs car.

Well, that is certainly not my experience. I've had mine in place since 6/2011, about 95 days on track and haven't had to replace the discs. Clearly I am doing it wrong.

Mine is a stock motor with I/H/E, ie low power. Maybe that makes the difference.

robert

I haven't driven my twin disk too much. Coming from a horribly slipping and pedal that requires 0 effort to push in to the twin disk I usually don't have trouble driving it. It seems that once I start driving it more I should be able to drive it pretty easily.

I wouldn't buy anything but twin-disk.
- less load on tranny
- faster shifting
- less inertia

Drove a 949 twin disk on the street
Would never buy one for a street car
Would absolutely buy one for a race car tho
Just my .02

twin organics with stiffer spring would be a streetable option for 400 hp...

I have one of each. I could DD the twin organic smoothly without a problem. The ceramic is a little harder, but I can still pull a car onto a trailer with it. I really doubt pulling the car onto a trailer wears the discs significantly.

I would love to go to the 949 twin. I have driven cars with them and I would not have an issue even daily driving them actually slightly smoother than what I’m using now.

Currently though I am and have been running a 1.6l Fadanza 7 lb flywheel with a 1.6l ACT extreme pressure plate and an un-sprung 4 Puck Disk. The setup is several pounds lighter with a much lower inertia than a 1.8l setup. I can drive it just fine on the street but it is certainly not OEM smooth like. I can launch it Ok as I have won some National event Pro Solos with it. It is about as light as you can go short of the twin. It has held up fine and holds somewhere well over 300ft-lbs of rear wheel torque. The sprung centers tend to blow apart on me though and since they tend to bottom out hard at these power levels in there range of isolation I don’t think they actually are any easier on transmissions than the un-sprung.

From My experience ACT seems to be conservative on their torque ratings I’ve gon way over on a few of their clutches and they have held. Some other clutch suppliers I have found not to be conservative. Spec pretty much fails right at the rated torque.

Thanks for all the inputs. Actually 949 twin ceramic disks and OS Ginken Ts2bs twin disks were my two choices since they are in same price range for me. Has any one used OS twins ?? Any thoughts on it ??

I'm running a Competition Clutch Stage 4 (sprung ceramic 6 puck) on a built 1.8 with EFR 6258 and 6 speed. Just from breaking the motor in, it felt fine driving around. Clutch pressure is surprisingly light.

Almost stalled once but I think that's more because of the light weight fly wheel. Never did any hard pulls since I need to track down an oil leak and finish breaking in/tune

I cant find any spec data on the OS like what is the weight or rated torque capacity.

949 twin is like 14 lbs in organic twin

My 1.6l setup with ACT Ive been using for years is only a little over 15 lbs and cheap by comparison works suprisingly well for the application.

I would bet the OS Giken is heavy by comparison.

How is your setup so light? It should be closer to like 16-18 depending on how much lighter than 4 puck friction disk is than the stocker. 7 pounds for the flywheel 8-9 pounds for the pressure plate 1.5-3 pounds for the friction disk. The weight advantage the speed sport has is that a good chunk of the pressure plate is aluminum since the friction surface is carbon fiber rather than steel.

FW = 7.3 lbs
pp = 7.2 lbs
solid disk = 1.5 lbs.

all the 1.8l stuff seems to end up over 20 lbs total. 1.8l pp is over 9 lbs I beleve.

Racing Multi-Plate | OS Racing Clutch | Products | OS GIKEN

Looks like the lightest OS twin is advertised at 19.4 lbs. for clutch and flywheel. There single plate is 22.5 lbs. They give no torque ratings. difference between billet aluminum or pressed steel pressure plate is only 0.33 lbs on the single.

Seems pretty easy to get that weight with a clutch that has a known acceptable torque capacity and drivability for half the cost or less.

I’d take my 16l Fadanza, ACT Extreme puck disk over that.