Milling Flywheel

[Homer]

Has anyone ever milled their flywheel to lose some weight? I have heard that there is a noticable difference when your clutch engauges.

[evilmiata]

Re: Milling Flywheel

Has anyone ever milled their flywheel to lose some weight? I have heard that there is a noticable difference when your clutch engauges.

post a picture, front and back. I have yet to pick up a flywheel for my project, and am interested as well. What is the stock weight? For reference, a stock Mazda 20# wheel can only loose 4#.

[Anonymous]

If you're interested, Fidanza makes an aluminium flywheel... not sure if it fits RWD apps tho.

[RacerX11]

Lighter flywheels do help the engine spin up quicker. The throttle response gets quicker, but there is less rotational inertia, so it is harder to get going from a stop (easier to stall). The stock neutral balance 660 flywheel is only about 15 pounds, which is light when compared to a lot of late model import cars (20-30 pounds). You can machine some off the back side of the stock cast flywheel to reduce weight, but you will also be weakening it. I don't know if there is a given amount you can take off before it becomes unsafe. I turned an external balance flywheel into a neutral balance one by removing the counterweight, and removing a little material from the backsde (maybe 1 pound), but I didn't want to risk any more. I changed a lot of other things on the engie at the same time, so it was hard to compare the performance difference.

You are better off spending the money on the Firdanza aluminum flywheel (8 pounds). Especially when you remember that if you weaken the stock one too much, you have a hand grenade spinning at 5000+ rpm pointed right at you. Kinda makes me want to consider a scatter shield :-) The Firdanza will work on any neutral balance 660, FWD or RWD (except for the 3.4 DOHC with Getrag HM284 tranny...I have heard this flywheel is different)

Marty

[evilmiata]

Lighter flywheels do help the engine spin up quicker. The throttle response gets quicker, but there is less rotational inertia, so it is harder to get going from a stop (easier to stall). The stock neutral balance 660 flywheel is only about 15 pounds, which is light when compared to a lot of late model import cars (20-30 pounds). You can machine some off the back side of the stock cast flywheel to reduce weight, but you will also be weakening it. I don't know if there is a given amount you can take off before it becomes unsafe. I turned an external balance flywheel into a neutral balance one by removing the counterweight, and removing a little material from the backsde (maybe 1 pound), but I didn't want to risk any more. I changed a lot of other things on the engie at the same time, so it was hard to compare the performance difference.

You are better off spending the money on the Firdanza aluminum flywheel (8 pounds). Especially when you remember that if you weaken the stock one too much, you have a hand grenade spinning at 5000+ rpm pointed right at you. Kinda makes me want to consider a scatter shield :-) The Firdanza will work on any neutral balance 660, FWD or RWD (except for the 3.4 DOHC with Getrag HM284 tranny...I have heard this flywheel is different)

Marty

Where can I find the fidanza flywheel? http://www.aluminumflywheels.com/docs/flywheel.pdf

[RacerX11]

J-body performance sells one: http://www.jbodyperformance.com/transmission.html
Here's an add on a J-ody site for one: http://www.j-body.org/classifieds/detail.php?item=20294

Just do a Google search for Fidanza, Flywheel, 2.8, and 3.1 . I picked mine up Ebay. A lot of places who used to sell the V6 one don't anymore, so they are harder to find. But they are available.

Marty

[SappySE107]

i think it works with the DOHC, since michael is using an aluminum flywheel in his Z34. Pretty sure thats the brand that made it.

[v6h.o.]

SPEC clutches makes the fidanza flywheel,
i had a email about a year ago from Tom Fidanza stating the part number, and he also listed his sources part number as well, which was spec IIRC... should have that email saved somewhere around here...

i did the same thing as marty did, i put the flywheel on our brake lathe machine and machined the backside of the flywheel to remove a slight amount of material, had it checked for balance.

the otherway to remove material is by drilling into the outer edge of the flywheel (where the clutch does not make contact at all) and drill holes part way (not through) the flywheel to lighten it up a small amount.