how much can I lighten my stock flywheel?

Nate S · Post by **Nate S** » Wed Jan 29, 2003 7:08 am

Hey all,
I am going to lighten my stock flywheel before i drop my 5mt in ( whoo got all the parts now ) and I am wondering whats a safe amount, I know someone on here took thiers down to 16lbs but I want to double check it. I am getting this done for free through a friend at a machine shop so thats why I am not just buying a light one to begin with.

Thanks,
nate

Aaron's ej22t · Post by **Aaron's ej22t** » Wed Jan 29, 2003 9:24 am

safety and weight isn't really the concern. the fact is, you shouldn't machine down a stock flywheel to make it lighter. it can reduce the strength of the flywheel and could cause problems. some people may disagree with me, but go ahead if you want to,.....it is just something i would not do.

Post by **Legacy777** » Wed Jan 29, 2003 3:44 pm

Don't do it......When you machine down the fly wheel you change it's engaging/disengaging point. The hyd. clutch is setup to engage at a certain point......by machining the flywheel, you change that point, and the clutch will either engage too close to the floor, or too far away.

entirelyturbo · Post by **entirelyturbo** » Wed Jan 29, 2003 6:38 pm

If you don't have a terribly powerful engine or 4WD, you can probably get away with shaving yours, my friend's Scirocco has a shaved flywheel and has had no problems, but he's FWD and doesn't have power...

If you do have power (like an EJ22T for instance

), then you could just possibly blow the thing up... it will shatter upon rough engagement because shaving exposes the weaknesses in the metal...

boostjunkie · Post by **boostjunkie** » Wed Jan 29, 2003 7:26 pm

Like everyone has stated, I wouldn't shave the stock flywheel unless you get a scattershield . . . although that modification adds considerable weight to the car anyway, so it would probably negate from the effects of the lightening

Imagine this:
Your accelerating hard and the flywheel grenades, causing the pieces to go right through the floor severing both legs or worse.

Yes, worst-case scenarios but it has happened.

We don't have too many members on this board so we can't spare to lose any to random mishaps such as this.

Nate S · Post by **Nate S** » Wed Jan 29, 2003 9:16 pm

wow, uh ok then.
I swore there was someone who lightened thiers, but if this is the case I guess I will just skip it till I can afford a aftermarket light one.
thanks for the help.
Nate

scottzg · Post by **scottzg** » Thu Jan 30, 2003 3:55 am

if you want a more effective way to reduce drivetrain energy loss, why dont you rip out 4wd? I mean, lightening the flywheel does hardly anything, and its makes the car drive a little wierd. BTW, somebody said that lightening up the flywheel messes up the hydraulic clutch, but i know i have a cable controlled clutch. whats up? a turbo difference?

Post by **Legacy777** » Thu Jan 30, 2003 4:29 am

A lightened flywheel does not mess with the hyd clutch....shaving or resurfacing it changes the engagement point. and yes.....if you have a cable clutch.....you shouldn't have to worry about it.....(shouldn't is the key word.....but I still wouldn't do it....)

Nate S · Post by **Nate S** » Thu Jan 30, 2003 5:25 am

whats the point of a subaru then?

I wont take out the awd but I am looking to make it a little more responsive.

scottzg wrote:if you want a more effective way to reduce drivetrain energy loss, why dont you rip out 4wd? I mean, lightening the flywheel does hardly anything, and its makes the car drive a little wierd. BTW, somebody said that lightening up the flywheel messes up the hydraulic clutch, but i know i have a cable controlled clutch. whats up? a turbo difference?

boostjunkie · Post by **boostjunkie** » Thu Jan 30, 2003 3:24 pm

I had a lightweight flywheel in my old 2.5GT. I actually still have it, if anyone's interested that has a N/A legacy or impreza. It's a 12lb chromoly flywheel that I got from ISR Performance. It has something like 15,000 miles on it (my headgaskets blew and I dropped a new motor in but the mechanic forgot to install it.

I noticed much better acceleration in 1st and 2nd gears. All other gears didn't change. Too a little while to adjust to the lighter unit (had to slip the clutch a little more), but all in all, I'd say it was worthwhile.

entirelyturbo · Post by **entirelyturbo** » Thu Jan 30, 2003 3:49 pm

boostjunkie wrote:I had a lightweight flywheel in my old 2.5GT. I actually still have it, if anyone's interested that has a N/A legacy or impreza. It's a 12lb chromoly flywheel that I got from ISR Performance.

Nate, this is what you're looking for. It's lighter, but stronger, won't explode...

Also try a pulley set, they work on the same principle, to reduce rotating mass on the crank... I was going to put some on mine, but I ended up stopping the project...

ej22t · Post by **ej22t** » Thu Jan 30, 2003 7:00 pm

I have a lighted and balance flywheele that lighted from my Legacy turbo. I am willing to sell it, gives me a PM if you wants the pics.

Ben

Nate S · Post by **Nate S** » Thu Jan 30, 2003 7:38 pm

boostjunkie wrote:I had a lightweight flywheel in my old 2.5GT. I actually still have it, if anyone's interested that has a N/A legacy or impreza.

sent ya a pm about this.
--nate

boostjunkie · Post by **boostjunkie** » Thu Jan 30, 2003 8:19 pm

replied.

-K- · Post by **-K-** » Wed Feb 19, 2003 4:26 am

I got an aluminum flywheel from SPEC, it's for a WRX but would work. I got the full kevlar stageII clutch also for WRX. It's just a little bit bigger so your clutch would work fine on the flywheel but not the other way around. anyway, it is great! I can feel it in 1st and heel toe downshifts are so much better. I don't think it makes it hard to drive or weird, just better. much better.

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how much can I lighten my stock flywheel?

how much can I lighten my stock flywheel?