lightened flywheel

[FierceGT]

I'm thinking of upgrading to an aluminum flywheel in one of my '85 Gt's. Has anyone done this? If so what kind of performance gains are there? The only thing I can find is that it reduces acceleration times...but that's obvious. I want some hard numbers. Also, how does this affect the way the car feels...letting the clutch out off the line, and shifting gears?

[Ragtop_Renegade]

I haven't experienced one on a Fiero, so I couldn't give you hard data, but on other cars I've noticed they reduce driveline drag quite a bit and give you a more sensetive clutch that requires a smooth, steady foot (and sometimes double clutching) to avoid grabbing and jerking. This isn't really a bad thing, unless you prefer the "punch it and dump the clutch" driving method.

[goatnipples2002]

It may be cheaper to have the stock FW lightened? How much does the stock one way? How much can be shaved off.

[FierceGT]

I can't find any real numbers but this is one that I was thinking about. http://members.shaw.ca/turbofiero/SSBflywheel.htm

[goatnipples2002]

Originally Posted by FierceGT

I can't find any real numbers but this is one that I was thinking about. http://members.shaw.ca/turbofiero/SSBflywheel.htm

Alot of people on pennock's are complaining about the quality of the headers they make because they break very easily so that brings me to wonder about the quality of their other products.

[FierceGT]

Well the only reason I was leaning towards that one is because they are the only ones that give any usefull information. The Fiero Store also sells one for about the same price. I'm kind of worried how the engine will react to the lighter flywheel....will the RPM's drop too fast when you push the clutch, will the computer be able to adjust fast enough? I have an ADS Superchip already, but I'm not convinced that really helps any.

[Ragtop_Renegade]

Originally Posted by goatnipples2002

It may be cheaper to have the stock FW lightened? How much does the stock one way? How much can be shaved off.

GM leaves only a little extra for cleaning up marring and glazing on the contact surface when changing the friction disc. Taking it off has no real effect on performance, and trying to take off extra reduces heat transfer and leads to cracked flywheels. For an improvement you need a flywheel big enough to take the heat but made of an alloy light enough to drastically lower the drag. Stock steel flywheels don't cut it.


FierceGT - If the flywheel weighs less, the rpms will drop slower, not faster. Less weight, less drag.

[FierceGT]

When you let off the gas, the compression of the engine tends to slow the engine....the parts that are already in motion...including the flywheel...want to stay in motion, so the larger the mass the more force there is behind it.....Newton's first law of motion.

[Ragtop_Renegade]

Originally Posted by FierceGT

When you let off the gas, the compression of the engine tends to slow the engine....the parts that are already in motion...including the flywheel...want to stay in motion, so the larger the mass the more force there is behind it.....Newton's first law of motion.

hmmmm, good point. What I'm thinking is the crankshaft is counterweighted, so gravity HELPS it keep momentum, but a flywheel is neutrally balanced and therefore gravity has an equal effect on it, so one with more mass should be affected more by gravity and therefore lose momentum faster, they bigger they are the harder they fall and so forth... 3rd law of motion, an object in motion stays in motion until affected by an outside force, in this case gravity.

Who's right? I have no clue.... If I did I'd probably be teaching at an ivy league school and driving a Ferrari