stroker questions

[302 LX Eric]

Originally posted by Simi Stang
I too thought about getting a lightweight aluminum flywheel a while back. But my '90GT is a street/strip car...and I was told that for street/strip applications like mine, aluminum flywheels aren't the best choice, especially with a manual trans. When shifting between gears...the alum. flywheel doesn't carry the inertia of the steel one. Therefore the RPMs drop in between shifts...significantly faster than a steel flywheel, which can make street driving more difficult. I'd like to hear from anyone that does run an aluminum flywheel though...how they like it...if they drive their car on the street at all, etc.

There was an excellent article a while back in MM&FF about the differences of steel vs. aluminum flywheels. Good information and I think it helped clear up some misconceptions.

I have one on my car and as far as street driving goes, it makes no difference as compared to my old steel one.

At the strip, it's just about the same to launch, except that it doesn't have the same 'hit' when you release the clutch at a given RPM. Easy to rectify by merely raising the RPMs (and we're not talking a whole lot here).

In almost all cases, your car will pick-up ET & MPH with an aluminum flywheel. Think about it this way...many people ditch the stock driveshaft for the lighter aluminum version in order to rid the driveline of rotating mass, or in a similar example, we put on lightweight racing wheels, as opposed to the heavy stockers, again, in an effort to reduce rotating mass. The same holds true for the flywheel, or lightweight pistons, I-beams, etc.

The most noticible downside to reducing rotating mass is the 'hit' to the tires when you drop the clutch at an equal RPM. If you've got 200 pounds of metal swinging at 5000 rpms vs. only 100 pounds of metal at 5000 rpms, the energy released upon the tires will be greater with the heavier driveline. However, as soon as the 'hit' is over with, the engine has to start working again to bring up the rpms through every single gear. This is where the lighter weight driveline really comes on strong. In a very heavy car, you would want a heavier driveline to help get the car rolling off the line, however my Mustang is relatively lightweight and I have absolutely no problem roasting the tires at the drop of a hat. In fact, I struggle just to keep the tires from spinning while launching the car at the track on drag radials.

The article in MM&FF had more technical girth to it than my simple examples above, but I think you see what I'm saying.

Hope this helps,
E