whats the pros and cons of a steel flywheel vs. an alum??

i know the alum. one weights less but is there anything else i need to know? thanks

Generally, the lighter the flywheel the more you have to rev it to get the car going so it doesn't bog on you. Inertia thing. Also, lighter, the faster the engine revs through the gears.

Finding lost hp mods:

Reduced rotating mass, reduce friction, and eliminate any incoming flow restriction. Lightweight flywheels and clutches help. My Textralia steel flywheel and clutch is 6 lbs lighter than stock. An LS7 clutch is a few pounds heavier than stock. An aluminum flywheel may free up some ponies on the dyno, but it will hurt your 60' times, so I did not choose to run one. Aluminum driveshafts make more power. Stock rear ends make more power (although mine has 3.73 gears because I wanted to go quicker).

From... Post 14.
http://www.ls1tech.com/forums/showthread.php?t=732392

From... Post 14.
http://www.ls1tech.com/forums/showthread.php?t=732392


An aluminum flywheel may free up some ponies on the dyno, but it will hurt your 60' times
I really don't want to read through the entire thread since it looks as though it's more about the car than the topic in this thread, but is there any timeslip proof of this? I've always heard this and have never seen a comparo.

I really don't want to read through the entire thread since it looks as though it's more about the car than the topic in this thread, but is there any timeslip proof of this? I've always heard this and have never seen a comparo.
i cant offer any proof (i.e. timeslips) but what i can say from what i have read on it:

Imagine u are spinning to flywheels/clutch assemblies using the engine one is aluminum(8lbs) the other steel(16lbs). The car is sitting still, same rpm(so they are spinning the same) through laws of physics the heavier flywheel/clutch assembly will have more kinetic energy(due to roational inertia (inertia is the resistance to change acceleration)), and thus this energy will be transfered to the wheels when the clutch engages.

i cant offer any proof (i.e. timeslips) but what i can say from what i have read on it:

Imagine u are spinning to flywheels/clutch assemblies using the engine one is aluminum(8lbs) the other steel(16lbs). The car is sitting still, same rpm(so they are spinning the same) through laws of physics the heavier flywheel/clutch assembly will have more kinetic energy(due to roational inertia (inertia is the resistance to change acceleration)), and thus this energy will be transfered to the wheels when the clutch engages.
I know it will have more energy, but is it really enough to make a difference? I'm not quite sure. Perhaps it's more influenced with stock like torque...
Agian... I've heard for years how a lighter flywheel is bad for drag racing, but it's all been hearsay.

it doesn't take 60' to transfer that energy.

if you learn how to launch the light flywheel your short times should actually get better. the hard part is learning how to keep the rpms right so that you don't bog the motor.

once the clutch is engaged and not slipping....the light flywheel will ONLY increase performance



considering i have a fidanza on my car i'll give my $.02

now granted this was installed with a SPEC 4 solid disc clutch...

- slightly increased vibration while driving...probably due to less mass to soak up the vibrations. also could be that i feel it more since motor, trans, and TA bushings are all poly

- backing up and slow forward are tricky....times when you'd normally ride the clutch. but also i have a cam and the race clutch...a clutch that doesn't allow much slip to begin with (so how much is the FW...no idea)

- shifting at very light throttle at slower speeds is a bit rougher...again could be due to clutch

- car revs up really fast in neutral...it jumps at the slightest tap of the throttle

- definatly accelerated faster

- more responsive to downshifting in corners or when aproaching a stop

I have a fidanza Alum flywhweel with a stage 3 ceramic clutch. The take off is gonna be a bit tricky because it revs either too fast or you may bog it but that is rare in my case boggin it, when i had my original 93 Z t56 tranny with 4.10's i would launch in 2nd gear ofcourse that particular gear box had shorter 1st and 2nd gearing coupled with the 4.10's. The car revs fast especially 1st and 2nd gear, downshifts are very fast and as for me i see nothing but good from the aluminum flywheel and well worth the mod for me. You wanna rev fast and get to the higher rpms quicker. Its kinda cool when you race a stock LT1 steel flywheel versus one with an aluminum you can see when it revs quicker how you jump ahead a bit.

After installing the SLP billet flywheel and lightend pp my 60ft dropped about a tenth on street tires. Stock clutch & street tires 2.08's SLP clutch & street tires 1.99. Also as a bonus the 3 feet of tire spin on the 1-2 shift is gone.

Only con I observed was increased noise with clutch enguaged in neutral.

i have the fidanza flywheel as well and it does rev much quicker then the stock flywheel. Now as for as 60ft. time its hard to tell because i never went to the track with my old motor, but with my new motor (mods in sig) i got a crappy 2.4 60ft. I have a '93 6 speed tranny in my car with 4.10's so 1st, 2nd and some of 3rd was spinning with my 315 DR's. The car revs so quick and im going through the gears really fast. If i could do it all over again i would keep the Flywheel, go back to a 94-97 6 speed and maybe 3.73's

For drag racing, I've heard that it's better to go with the steel flywheel because it doesn't lose as much inertia during shifts. Meaning, it wants to keep turning and keeps up the momentum.

It was also recommended to me that aluminum is better for road racing/auto crossing because it's easier to get the RPM back down to where it needs to be for that application.

what about the McCleod street twin i ordered the steel wheel cuz it's my dd but with all the extra clutch would inertia be a factor if i had the Al one?