ACT Miata Flywheel - StreetLite

I swapped a stock 1.6 clutch on a mostly stock 1993 with a 1.8 clutch and wanted a "streetable" lighter weight flywheel with the stronger 1.8 clutch. I went with the stock replacement 1.8 Exedy clutch kit and the ACT 13.9 lb flywheel. If I were to do it again I'd pick a lighter weight flywheel. I don't really notice a difference with the new setup other than it feels like a new clutch vs a tired old clutch. The stock 1.6 flywheel (18.0 lb) plus the clutch cover (8.0 lb) is 26 lb of rotational mass. The lighter ACT flywheel (13.9 lb) plus the heavier 1.8 Exedy clutch cover (9.2 lb) is 23.1 lb of rotational mass which is 11% lighter. The problem with rotational mass is it matters where the mass is located with reference to the center of the flywheel. If the mass is more on the outside of the flywheel it will feel heavier in use. You can't measure that with a scale. This review is geared to those replacing a 1.6 clutch with a 1.8. I'm sure you'd notice a difference with the ACT flywheel if you are replacing a stock flywheel on a 1.8 engine.

Now a note on Goodwin customer service. When I bought this flywheel Goodwin listed it as 13 lb. When I weighed it at 13.9 lb, I messaged Goodwin with the discrepancy and they got back to me in a matter of hours. They contacted ACT and found out the company changed their flywheel weight from 13.0 lb to a 13.9 lb without notifying their vendors of the change. Goodwin offered to take the ACT flywheel back and swap it with another flywheel and cover all the shipping costs. I needed to get the car back on the road quickly so I declined. They immediately updated their website to show the correct weight and gave me a $40 credit on my next purchase. I couldn't ask for better customer service.

-- Keith C., Park City, UT ( 1993 Miata ) March 2024