Educate Me on Clutches and Flywheels
 

To save everyone some time: "OP, just get an FM1 Happy Meal," and I may just do this, but why not ask some questions and learn more along the way?

Im a complete noob when it comes to clutches. I have a build thread going on in the Media section, feel free to check it out if you are curious. One of the major bottle necks I still haven't worked out yet is my clutch setup.

Currently I am considering the FM1 Happy Meal or a Fidanza flywheel with an ACT Extreme full face (ZM2-XTSS). I expect both will do what I need them to (hold the bower of boost with stock internals), just with different drivability characteristics.

Here come the real questions....

I have been thoroughly scared away from "Ebay" clutches, but what about "Ebay" lightweight flywheels, such as the ones branded XTD? I imagines they would be fine as long as they were properly balanced and you used a quality pilot bearing.

Would it be reasonable to consider, or even possibly to mix and match pressure plates and clutch disks. I imagine the main issue would be the geometry between the two. I know there are a lot of factors that go into the various qualities of a clutch setup. Clutch disk friction material, face surface type, and clamping force being the major factors for torque rating. For the sake of argument, lets say I want to run an OEM or stage 1 type Exedy clutch disk with an ACT Extreme pressure plate, the advantage being it would reduce cost. Would this work? Has anyone done something of this nature before? If so, is there a formula to follow? What can I expect?

I personally do not like lightweight flywheels and the noises they can make on a street car. I will probably be one of the few with this opinion on here. I have always thought of saving that couple hundred dollars for a new flywheel and spending it elsewhere as a better use of funds.

Pulling off your exhaust, drive shaft, and then transmission, then putting it all back in takes a good bit of time. Anywhere from 2.5 hours to 10+. It is annoying to do no matter how fast you can do it. This reason alone is why I recommend a good clutch. SPM, FM, or ACT. I have seen cheaper and or mix matched ones have issues, and pulling the trans to fix them sucks. So factor that into your decision highly.

I use FM1 or SPM organic now for 99% of my clutch jobs. Generally it is whichever one is in stock when I need one. I have had good luck with both. ACT's have worked well for me, they just are a bit more expensive then the other two brands and hold a bit less torque.

Interesting angle on the flywheel. Besides noise, are there any other reasons you don't like lightweight flywheels? I have heard if you go too light, drivability can be severely effected. The time investment is most of the reason I am still panning to get a high quality clutch at the moment. By SPM, you mean Super Miata? (I haven't seen that acronym before)

Track car? sure. Any car that goes on the street? No to the flywheel. It can be done and daily driven, but it's one of the mods I undid to my car because I spend more time in traffic than I do on a track.

Ignore "stage" names. What you want to retain stock-like engagement is an organic disc. Puck clutches have a very quick engagement, but very little modulation between engaged and disengaged. An upgraded pressure plate results in higher pedal effort, but is really only apparent the first time you drive it and whenever you switch between manual vehicles. I think the zm2 xtss is what I ran - and other than high pedal pressure, it's very streetable.

I bought a 10.7 lb FM flywheel and I wouldn't go as far as to say I regretted it...but it took some finesse to get used to and I stall out allot more than I did with the stock flywheel. If I ever have to replace my clutch, I'll probably get a stock flywheel and resurface it, but that's me and you're you.

The über-lightweight super race spec fidanza flywheel is overkill and unnecessary for a street-driven car.

You might be overthinking a bit.
Removing and replacing clutches is a pain in the arse and the fewer times you have to do it the better.

One of my cars has a 1.6 ACT HDR4 (4 puck unsprung) and a light flywheel. It's easy to drive. Cake. Easy to drive smooth, too.

The other has a 1.8 ACT HDSS with a Prolite flywheel. It's also easy to drive. Feels like stock. 10/10.

Would drive either on the street with no complaints.

stock resurfaced flywheel and FM1 clutch is the best combo for stock like drive-ability and feel with plenty of holding power.
Thats what i run in my last and current miatas.

had an FM lvl 2 clutch and FM light flywheel (FM2 Happymeal), and was not crazy about it....
was it driveable? sure. but pedal was considerably stiffer, starting was not as smooth/easy, and rpm's dropped faster, so i could not granny shift the car, had to shift faster.

ACT ZM2-XTSS user here. It uses a normal style friction material and a stronger pressure plate clamping force to hold big power. The HDSS version is a less powerful pressure plate with the same clutch disc. It was fine for me although the effort was a little higher than stock. My little wife didn't have any problems with it.

I used a 12ish pound moly steel flywheel instead of the 18lb stock unit. It accelerated a little quicker in the first two gears when naturally aspirated. With a turbo the effect would likely be less well perceived because of the additional power. The lighter flywheel made a negative difference in idle recovery and A/C dip. I also believe the energy storage and smoothing effect of a heavier flywheel is important for oil pump and transmission preservation.

I would not use an aluminum flywheel with the BP engine since they are known to be awful for harmonics and balance.* I would also shy away from it if using air conditioning or primarily street driving for idle stability sake. Not that it can't be done, but it does add a level of difficulty.

*The exception would be in a pure racing environment where the engine would be rebuilt often.

In another thread, I have discussed what I thought was short life on FM1. Indeed, the release is now at the top of the pedal stroke.

Can I / should I / use the SM or ACT clutch disk with the FM PP? If I did so, should I expect a longer life?

Typically a new PP is replaced with a clutch disc but if it is very new then maybe you could get away with it. Obviously better to do both.

Thanks for all the feedback guys, specifically on the lightweight flywheel. I will probably just stray away from that at the moment and put that money somewhere else, especially because I plan to run AC. As for the clutch, sounds like everyone has had ok luck with FM1 and XTSS, so I will probably head that route instead of doing something funky trying to mix and match parts.

A heavier pressure plate could be remedied by altering the hydraulic ratio through choosing a different bore slave; actually I am amazed that there's no aftermarket option for this.

I have a cheap F1 racing china ebay brand LW FW, 10lbs I think. I have countless tack days on it and couldn't be happier. When I went turbo, I resurfaced it and threw an ACT clutch kit on it, and couldn't be happier. Would daily a 10lb FW, all day.

Damn, I considered that but couldn't find any good info on it, Now you tell me!

Interesting. If I do go with a lighter flywheel, then maybe I will go the cheap rout incase I don't like it. That way all I am really sacrificing is my time and effort.... which isn't worth much lol.

On another note. Is anyone familiar with this M-Pact clutch (PN: 10045ST2X) available via RockAuto? They claim it's supposed to hold between 75-100% of the torque capacity of the stock clutch. (I assume they meant 175-200% lol). I assume this is similar to the Ebay XTD crap, but I figured I would ask since the ~$190 price tag is appealing, although it is a 6 puck.

If you want to do the job twice

As an FYI, a lot of people were getting F1 FWs for 1.8s without some of the holes tapped, or tapped to full depth, they were un-install-able. Id guess the chinese metallurgy leaves some things to be desired, but as long as the thing is machined properly, which mine was, I see no issue saving a few dollars on a FW. Also they claim these are chromoloy, not even sure they spec an alloy, but keep in mind the stock ones are just cast iron.

Also keep in mind, if they do grenade, you risk looking a leg or 2.... and that's not hyperbole.

I guess at the end of the day, that's the real reason I got an ACT Prolite... Thanks for the reminder

Well thats horrifying. Is this something that actually happens though? I mean, the pressure plate is bolted to the outside of the flywheel in several places. I feel like the chances of a piece of the flywheel sheering off with enough mass to shoot through both the bell housing and the transmission tunnel is pretty low.

Yeah? Just do a YouTube search.