lightened pulley + lightened Flywheel(lbs). Solve for 'lbs'

[Mr.Pessimist]

I've heard from more than one source in the past (cant find the websites now...) that if you have a lightened crank pulley you should'nt install a flywheel less than 14lbs. I guess lighter than 14lbs and you run into problems of starting the car from a stop, lack of momentum I'm guessing.

Anyone had any problems with this or know the correct weight of the flywheel when matched to a light crank pulley?

[vrg3]

If it's indeed possible to compute some kind of threshold, it would be a rotational moment of inertia that you'd be concerned with, not weight. For example, one 14-pound flywheel might have more weight near the center than another, and so have a lower moment of inertia.

[Legacy777]

Dave's got both....don't know the weight of his flywheel though.

[DLC]

I also have a low-compression engine...N/A is harder to start by default.

Mine's an Exedy, probably 12-14lbs. I've got an UOR lightweight pulley.

Never had a problem starting, have stalled the car less than a half-dozen times in the last 30 months.

[Mr.Pessimist]

I've been looking up flywheels and the "ACT streetlight" seems to be pretty nice especially for the price.

A guy on subarureview seems to be happy with his:

http://www.subarureview.com/showreview.php?id=1202

In addition, this place is selling them for $225 shipped! (bottom of page)

http://www.groupbuycenter.com/buy.aspx?id=14857

[BAC5.2]

I've got the Exedy, and I recomend it over the ACT. It's just a better quality flywheel.

The Exedy that Dave, Brat4by4, and I have are 14 pounds on the dot (give or take a tenth or so).

It's true, it's more difficult to get the car moving with a lightweight flywheel, but I've never had a problem.

I wouldn't go less than 14 pounds out of sheer mechanics. I've found that under WOT, when you shift, the engine slows JUST enough to be spot on for the next gear when you shift with the synchros. The downside (if you want to call it that) is that there is no hamfisting allowed, not without a violent drivetrain lash that is. I shift smoother at WOT pulls than I do under normal acceleration. At partial RPM shifts (say, around 5k or so), the revs fall to far and you've gotta rev match to get a nice smooth shift. Not a bad thing, but not always fun. I've become accustom to revmatching almost every shift.

I got my Exedy lightweight flywheel and Stage1 clutch for $719 shipped. My car is significantly more responsive and significantly faster (a 4psi pull in 4th gear pulls better and harder than an 8psi pull in 4th gear with the stock flywheel).