Flyin Miata Stage 1 Clutch Thickness
 

Bought a used FM Stage 1 clutch and couldn't find the thickness spec for a new one online. Called FM and they said it was .308 inches. Hopefully this saves someone a call in the future.

I will post my findings after a failed 626 disc with a flying miata pressure plate( can't use a 225mm 626 disc on a stock 1.8 miata sized pressure plate, learned the hard way). Clutch disc exedy part number mzd010u less then 100 miles measured 8.7mm across ( pp side friction =3.7mm and flywheel is 3.5mm) . The flying miata supplied clutch disc measured 8.0mm with about 5k claimed miles. ( both pp and flywheel side measured 3.5mm). If anyone with an act clutch kit is in need of a replacement 225mm disc you might want to look into the 626 2.5l disc (8.6mm total friction). It's has the same friction material thickness of the 1.8 miata exedy Oem disc. Some also interesting notes can be found through maruha website. The 626 disc also has the hub face shorter by .11mm but the spline is extended a little. Flyin miata measured an increase of 1.0mm of hub height difference. Sorry I was not able to get the spline measurement. Also the flying miata disc is dual spring for added torque absorption but the hub is also bigger then the stock 1.8 exedy.

Weight
Exedy Weight1.8 mzd010u= 2.6lbs
Flying miata = 3lbs
626 2.5l 225mm= 2.6lbs

Hub round
Exedy 1.8= 120mm
Flying miata= 133mm
626=120mm


For kicks and giggles the stock miata exedy replacement pp weights the same as the Flyin miata at 9.1 lbs.
My new xtd flywheel weighed in at 11.3 as advertised.
Please these are my own measurements that I'm sharing and might not be as accurate. Please do your own deeper research. My tools aren't precision and some items might be out of calibration. Again this is based off some used stuff and the accuracy might be a bit off from brand new. I just find it a bit interesting as flying miata says .308 which is very close to my findings of a clutch with 5k miles. If I was to compress the disc I'm sure the 8.00mm will drop at least .10mm.


It's seems the fly in miata hub could be a very close design to the msm Oem disc (bp12-26-460). Although it seems that disc uses the same friction thickness on pp and flywheel side where the Oem msm pp side is recorded a tad bit thicker.

My next attempt is to run the flying miata pressure plate with a stock exedy Oem 215mm mzd010u disc for longevity. This has nothing against anyone ... Just some numbers. I still believe the fm kits are great kits for a miata.

For the record, the flywheel "depth" should be about 19.87 mm.
I'm obviously talking about the two step flywheels here.

If the depth is right at 20 mm or (god forbid) more, you will get gonorrhea premature clutch slippage.