What to clutch it ?
 

Hey,

I'm running an NA8 turbo that puts out about 250lb/ft at the wheels.

I need an a appropriate clutch for the job, FM1 ? ACT1? ACT2?
FM stage 1 advertised as a 318lb/ft clutch
ACT HDSS = 245
ACT XTSS = 315

I hear/read about issues with the FM clutch, two clients of mine complain about there FM clutch, another one does not - I tuned there NB turbo.

Which of them have the highest chance of giving me trouble free running and would be strong enough ?

Thanks !

What are the complaints of the FM clutch?

Have you searched? There are threads dedicated to discussing this very topic.

I use FM clutches in all my cars. FM1 holds more torque then any of the similar ACT and costs less.

Easy button

https://www.miataturbo.net/general-m...-clutch-34873/

https://www.miataturbo.net/suspensio...-300whp-83306/

https://www.miataturbo.net/suspensio...dations-22587/

https://www.miataturbo.net/suspensio...0-400hp-78495/

https://www.miataturbo.net/suspensio...-clutch-87966/

And your own thread you started asking the same


https://www.miataturbo.net/suspensio...m2-hdss-73578/


Boooooo. I don't like you.

FM2 here, just fine for daily, plenty of holding power for my boosted turd.

Ps. You're and retard.

Did I do that right?

2013...

ahh ?

No excuse for your inability to search. And what has changed in clutch technology in the past 5 years?

This is the question on mind right now, I did search and read around.

Every freaking time I ask a question here, I get this patronising stupid attitude, why do I need to explain why I ask a question here?

This is bad community right there!

every freaking time!

Seriously since FM came out with their clutch 7-8 years ago. They have really been the goto. 949 offered the twin disks for the hardcore track users. Now 949 has their street clutches. Other then that clutches have not changed much in the miata world.

Bad community would be not spoon feeding you every single time you ask stupid questions which could be linked to multiple threads offering you answers. You still got your answers but put some big boy pants on and question why it is you've been getting patronizing attitudes.

ill take my stupid questions else where.
this forum members welcome only other members they know.

i do not need this

See you in another three years.

It seems that way...but it isn't. I don't know one single member on this forum, outside of the interweb.

I had your same question, searched, read about 6 different threads, then made an educated decision based on my findings. I was already the owner of a twin disc set up, based on my own research I had decided that for my intended use, a FM2 was my best bet. Sold the unused twin.

I did all of this without asking a single question.

The mob mentality is provoked by users feeling of self entitlement and/or the inability to search and learn from their own findings. This brings out the worst in MT.

You can always go to that other miata site. They will gladly dish up the weekly line of untested, uneducated and disproven bull shit.

I still don't get why a "Discussion Forum" cant be just a little bit nicer to new people?.....Sometimes people just don't know what they are reading or need to research with the right way to format or ask a question.



I'm re thinking my clutch requirements and am looking up clutch threads despite "clutch technology not changing in the past x years".

The OP even has relevant experience to draw from against the FM1 clutches (rightly or wrongly).... and so has raised the question.

So to the OP, i have had a good experience with FM 1 ( i think its was a 1) and haven't heard about many (any) issues with them.

BUT I have the same/similar question as what i think the OP was getting at..

I know the FM1 is great in my old car and have an ACT in my current race car at 230 - 250 wtq but my new race car is hopefully over the next year or two getting up to 300.

Do you need headroom in a clutch or is getting the same rating as you have fine? i.e. if you have an engine with 250 wtq do you buy a clutch to the same rating or add 25% or more for headroom, longevity etc....

Your going to stand off the edge of a cliff. It's like 400 feet in the air. It's fun and you like the excitement.

A 2x4 piece of wood you have at home supports 150 lbs. Before it snaps.
You weigh 148 lbs. The wood should hold you.
Lowes is down the street and sells 2x6 material that supports 225 lbs before it snaps.

I know what I would do.


All the sarcasm aside, the FM2 clutch hOlds a lot of power. I don't know my HP, but VVT with 20+ psi boost, absolutely no problem. I went to the drag strip (never before, probably never again) a few months ago. Slipping the clutch for 60 ft at 6,000 rpm (because 2ND gear starts & wheel spin) 6 times. Made a ton of stink. Clutch didn't ever slip or fade. Still works just fin. In fact I think for street driving, it felt better after the drags.

Haha, nice analogy.

I realise that I could go for the highest rating but then transmission drive train shock ( solid puck) pedal feel and driveability are affected by going to the top of the tree..not to mention spending unnecessary dollars on a clutch that is more than required are factors that I am debating....

I did consider the 949 twin plate but reality is it is massive overkill for the 1600 turbo (though i like the central mass idea) and considerably more coin that could be spent on other parts.

The hard part is I am trying to buy the best parts available for this build but without going silly, deciding where to draw the line is the tricky part....(xidas are close to being ordered etc)

Fm2 sprung puck.

I think I found the answer to the clutch question.

And, it is machining the flywheel correctly..

The depth should be no more than 19 mm. Period.
I experimented with 18.65 mm, and it is just perfect.

The FM 1 clutch is very capable, but if your flywheel depth is over 19 mm, it will not last.
Also, the flywheel surface must be ground, not turned with a sharp bit.

I found a machinist who uses a high speed grinding stone on a fast lathe, and then finishes the surface with a very fine diamond bit.
Excellent results.
(I should have a couple pics somewhere, I will post them if I can find them)