Miata Turbo Forum - Boost cars, acquire cats. - smoked my clutch, what should I get now?

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- - smoked my clutch, what should I get now? (https://www.miataturbo.net/suspension-brakes-drivetrain-49/smoked-my-clutch-what-should-i-get-now-93273/)

Quote:

Originally Posted by thumpetto007 (Post 1415950)

Well, I should have said, don't waste your money on parts that FM resells. They purposely use low cost parts. I have had nothing but early parts failures from them. clutch slaves (two of them rusted out and leaked in under 6 months) throw out bearings/release bearings (one early failure and the replacement was defective) pressure plate (defective and was causing clutch slip with stock power levels)

I just tell people to steer clear of their low cost high volume high profit parts. Just my opinion and experience with them.

I've gone though 3 clutches in 3 years, and I'm finally happy with the sprung pucked 949 clutch. They have a lower profit margin, much higher quality components.

Sure I only have stock power levels, but I'm just giving my input on clutches. I don't want other people to deal with the crap I've dealt with, just trying to look out for members if I can help them. If I'm wrong, fine, but I'm still steering people towards the higher quality clutch.

I feel like you're definitely an outlier. Their clutches are always the first to be recommended and they don't have a reputation for faulty parts. Most users have been more than satisfied with their clutches. I had to replace the clutch disc on mine after 50k mile due to a leaky rear main seal and the disc still had plenty of thickness to it. It sounds more like you just got incredibly unlucky.

Quote:

Originally Posted by thumpetto007 (Post 1415945)

Spec, Competition... all equally low quality.

Competition clutch manufactures the twin disk. Which seems to be pretty good...

Fwiw I recently upgraded to 949 twin disc carbon/Kevlar and find it to have really good manners once adjusted properly for shorter travel. As light or lighter than oem clutch in my 05 wrangler. The faster revs are awesome too if you don't mind a little buzz on decel.

I went with FM2 on my last rebuild and found it to be both strong and comfortable. Basically stock feel but way stronger. I don't mean it's exactly like a stock clutch (which was incredibly soft) just much closer to stock feel than my old six puck setup.

Only really notable things about it compared to stock are:

Long pedal travel. Really long. You will have to adjust stuff.
Slightly stiff but nothing terrible. I'm guessing this is paid for via long pedal travel
Easy to engage/modulate

For the strength you get it's pretty easy to live with. I file the complaints about the FM2 with the complaints about poly motor mounts. It's the sort of shit people complain about the first day and then they get used to it and stop caring.

Quote:

Originally Posted by afm (Post 1415967)

Competition clutch manufactures the twin disk. Which seems to be pretty good...

Competition Clutch also manufactures the FM clutch.

When my clutch slipped on the dyno I had it sent in and CC said nothing was wrong, car just overpowered it. Sent me a new one anyway and FM sold me a brand new one for half off. Sold those and bought the 949 Twin disk.

FM was easier to drive, I just wish it held up. Twin disk isn't so bad, but it's a sharper engagement way up high as adjusted per instructions.

Correct flywheel machining is paramount for clutch life, especially in a Miata.
The relationship between the flywheel surface AND the "steps" is often overlooked.

https://cimg1.ibsrv.net/gimg/www.mia...ce91887452.jpg

The "depth", meaning, how far the bosses stick out from the flywheel surface should be no more than 19 mm, and 18.65 mm is the ideal depth.
I have seen flywheels with over 20 mm depth, and one at 22 mm.
This significantly reduces clamping force and friction material life.

I stay right at 18.65 - 18.70 mm, and have not had a clutch problem ever since I found out about this little tidbit.

All you need is a straightedge and calipers, and you can measure your flywheel before installation to save a ton of headache later.