slowd16

Never have a problem driving on the street with my 8lbs and AC on. Just need to keep the revs up between shift/shift faster lol

anorexicpoodle

Ive had an 11lb and now have an 8lb both ACT. Pretty much zero downside to going lighter on this motor

I had a RX7 with a lightened flywheel and it made street driving hard because it was extremely easy to stall. The F22 doesn't have any qualms with a super light flywheel. Dont be put off itll feel great.

Also I liked the snappiness of the ACT PP and disk combo. Right now on ACD PP / OEM disk and preferred the feel of the upshifts with the ACT disk.

s2000Junky

me either.

DavidNJ

Question about weight: do you also consider the weight of the pressure plate and clutch or the moment of inertia instead of the weight alone?

ACT lists there PP/disks at 12-14 lbs. Adding the 8 lb flywheel that is 20-22 lb. That is about the same as the OS Giken and ClutchMasters 825, both listed at 22 lbs. The ClutchMasters 725 is listed as 16 lbs with the flywheel. I believe all of these use a 7.25 in diameter PP/disk, the smaller radius reducing inertia. Tilton and Quartermaster have 5.5" and 4.5" diameter clutches and pressure plates, but Idon't seem to have less than 7.25" listed for the S2000 or K24. The Tilton 7,25" carbon clutch/flywheel is listed at 12.3 lb.

Using 600rpm/sec as the engine's rate of acceleration, the difference between the lightest and the heaviest is probably 2 ft-lb—5 ft-lb. In really tight racing classes, 2hp-10hp can mean a lot; the difference between making a pass or having to back off. When the clutch is in, the effect seems large because the flywheel and clutch are a big part of the engine's total inertia.

s2000ellier

anyone who upgrades their PP should disable their clutch lockout switch

anorexicpoodle

Nope. The full scope of the thought I put into it was:

A: The car feels one way with the OEM AP2 flywheel
B: After installing the ACT 11lb flywheel it felt notably better with zero reduction in drivability and more critically not a huge reduction in the girth of my wallet
C: After installing the ACT 8lb flywheel response improved further, OEM like drivability was retained with literally zero down side.

At no point did any math not involving dollar signs, or anything measurable in anything more than smiles per mile enter the equation.

s2000Junky

There is no downside to lightening the flywheel on this car, only benefits, so lighter the better in my experience. If someone chooses a 10-11lb flywheel, they should have just saved their money and stuck with the 14lb ap1 flywheel. If your going to invest in the $300+ of an aftermarket option, do the lightest available- 8lb.

DavidNJ

Is it the quick response on upshifts and downshifts that you like?

SlowTeg

Flywheel weight is personal preference. If you do a lot of putzing around on the street and/or live in a hilly area, a very light flywheel is a pita. My F1 flywheel was $170 shipped..? Definitely worth it to me coming from an ap2. Regarding the <10lb flywheels. I'd invest in a chromoly one vs the aluminum ones out there w/ friction plates.

Pimpo

ACT Prolite at 8lb. doesn't feel overly light at all. I was actually a bit shocked after installing, I thought coming from a stock AP2 the difference would be much more noticeable. Don't get me wrong, it does feel much better, but it's not such a dramatic effect and the car is definitely easy to drive. Had I known I would have gone for a slightly lighter one, but no idea if anyone makes it and the ACT was tried and true by many.