Light weight flywheel for track 924S?

[The Glademister]

What's the potential performance gain by switching to an aluminum flywheel in my '88 924S? Something like this...

SPEC ALUMINUM FLYWHEEL 924S / 944 NA
Code: LR-SP-00A
Price: $439.00

I've heard rumors that will enable the engine to spool up much quicker. Maybe help me dig out of those low speed corners without down shifting.

If I get one - what's the shop time to make the switch? Going beyond a clutch job and installing with the engine in place or drop the engine?

[Techno Duck]

Its a good mod, improves shifting due to the engine responding faster when you rev and when you come off the gas. If this is a street only car i would consider lightening a stock flywheel rather than an aluminum flywheel. A stock flywheel is about 14-15lbs and can be lightened to about 9lbs and is a little easier to manage in traffic. The aluminum (Fidanza and Spec) weigh under 6lbs, my buddies EK hatch has a Fidanza 6lb flywheel and is a pain in traffic and uphill.

Dont expect huge power gains or anything like that. You will feel a difference in drivability though.

You can have the stock flywheel lightened and balanced for about $100 at your local machine shop. If you decide on the aluminum flywheel, make sure you get that balanced also as they are not perfect out of the box.

Installation time is basically a clutch job. Experienced shop time is in the 8hr range and is normally done with the engine in the car.

[The Glademister]

Thanks Jon. That confirms what I suspected. The Miata guys in CSP say it's really a must do to be competitive. You don't see any complications due to the 951 clutch and bell housing do you?

[Techno Duck]

Not sure what you mean by complications? Are you running a turbo bell housing and clutch setup on your 924S?

[The Glademister]

Yeah, there was a little misunderstanding when I first got the car and had a shop do work on it. I knew the clutch was bad and asked the owner "to put in a turbo clutch" meaning a spring loaded. Well, he did indeed put a new 951 clutch and used bell housing on it!

So I guess I'm just wondering about the mismatch with the aluminum NA flywheel and the 951 clutch. Surely it would all go back together just as it is now.

[Techno Duck]

Originally Posted by The Glademister

Yeah, there was a little misunderstanding when I first got the car and had a shop do work on it. I knew the clutch was bad and asked the owner "to put in a turbo clutch" meaning a spring loaded. Well, he did indeed put a new 951 clutch and used bell housing on it!

So I guess I'm just wondering about the mismatch with the aluminum NA flywheel and the 951 clutch. Surely it would all go back together just as it is now.

I would guess you have a turbo flywheel on the car also. The 951 clutch is a larger diameter and would not work on the standard n/a flywheel. Also the 951 bellhousing is slightly different (starter mounting area is thicker, moving it away from the ring gear) and would not work with a n/a clutch setup. The only part from the n/a on your car is probably the starter ring gear. Of course this is just conjecture on my part, only one way to find out whats really in there . If that is the case, you will need to get the turbo lightweight flywheel.

[The Glademister]

Sounds logical Jon. The NA and turbo Spec aluminum flywheels are the same price at Redline Motive.