I'm doing a build with an FM turbo kit (to start) with headroom to add boost and fuel later, if I want. What's everyone's take on clutches? Should I wait for the FM kit, buy the 949 kit, or get an ACT clutch and flywheel from Moss? Is there a better option/combination available? I have the ACT prolite flywheel now and love it. TIA.

 

Before anybody gives you a recommendation you should state your power goal. The GT2560 tops out around 275 RWHP, some have squeezed closer to 300 but that might be running more than 18 psi which is as hard as I plan on pushing mine. If that's where you think you might end up then you should buy one rated to hold that (crank) power. I went with SM Sport kit with the 4-puck friction disc. The only thing I'm unhappy about is mine squeals like a pig nearly every time I get moving from a stop, also into 2nd gear, sometimes into 3rd. With each change the noise lessens both in intensity and duration. With how hard it grabs and locks up, the lighter the flywheel, the more difficult it is to get moving smoothly in 1st gear. You can dump it into 2nd and avoid most of the noise in my car but that's harsh, a little slip is needed but the noise is almost embarrassing, similar to brake squeal. Had I known it might be this bad I would have chosen a different friction disc. If you never plan on running as much power as you can get from the GT2560, you might be able to use the normal, full face organic friction disc. It's been a long while since I checked the ratings, I was shooting for slightly higher than the organic disc was rated to hold but it's also said that the rating might be a bit conservative, some have reported the organic disc holding more power IIRC.

My car came with the FM happy meal level one kit. It was likely never fully adjusted properly, my car could barely be adjusted but by the time I got it, the flywheel was likely already slightly warped and the friction surface overheated and hardened. A local shop was able to resurface it, had to take a little more off to clean up the friction surface than normal and match the tower heights. There are quite a few reports of difficulty setting the master clutch cylinder pushrod length to hit that Goldilocks zone. It requires more travel and mine could barely disengage which is why I chose not to install their level two kit. Plus, I already had an ACT PP on a 1995 Escort GT that I turbocharged (1.8 BP engine) and wanted to keep the pedal pressure increase to a minimum. The SM PP feels great, some ACT PPs might hold but also might feel much heavier, requiring more force to push to disengage.

Lastly, my flywheel was 10.4# originally from what I have read, not sure how light it is now after the machine work, can't be much less than 10# but if i were to do it again, especially with the 4-puck disc, I'd stick with an OEM lightened FW, maybe shoot for 14-16 lbs simply because it would be easier to get moving more smoothly, and if you're tuning an aftermarket ECU, or maybe even with the OEM ECU, super light flywheels accelerate and decelerate more quickly which can make dropping back to idle less stable. Too light and you might get more idle RPM droop below target before recovering, or increase the chance of the engine stalling under load (electrical, steering, A/C, etc.).

 

Power goals are minimal compared to what I've seen some builds doing. 250 wheel or less. I know the transmission becomes a liability around 250 wheel, so I'd prefer to stay under that. May get a build trans later down the road

 

I’m personally a big fan of SuperMiata parts. I’m particularly impressed with their clutch - even before I fixed the throw-out bearing issues with my K-swap, and while those issues were destroying my clutch disk, it held the K-series power beautifully and despite being puck-type, was easy to modulate and super smooth.

 

I've decided to go with the Supermiata sport assembly, with the full (not puck) disc