Flywheel

[idiot_saabvant]

I'm looking for thoughts on lightening a steel flywheel, or at least having it balanced. Does one take the material off from the back side or does one mill the front were the clutch touches? I thought I read that one can remove about 2-4lbs from a stock steel flywheel.

pierre

[shaverjeff]

I've heard it was safe up to 7lbs removed from a guy at thelocal strip. He seemed pretty knowledgable and was in the low 15's with a pretty much stock (other than apc) spg.

If you can I would say spring for the aluminum I think my overall weight on ym sd unit is 7lbs I think the stock job is amost 20lbs. It is a bit more prone to stalling but it revs up like a motorbike.

[yfs87]

I would say you have a shop pull the clutch locating pins off the front side, then face it a few times, then replace pins. 5-7 pounds would make a big difference.

[idiot_saabvant]

So if I face the front (clutch side) of the flywheel, it will not effect engagement of clutch? Several pounds would be nice to remove.

pierre

[NSE]

I have read (by searching on SC) that you can safely take off 2kg - 3kg (4.5-6.5lbs) Anymore than that and you can run into drivability problems.

Here's a link to a photo and a little info: http://web.inter.nl.net/users/turbo-...e/flywheel.htm

[nutcase]

Be wary of taking overall thickness off the flywheel, if its too thin, the clutch slave may have to over extend and pop

[GlenM]

Flywheels are supposed to have material removed from the back, ie. the side away from the clutch.

[TooMany2cvs]

Originally Posted by idiot_saabvant

I'm looking for thoughts on lightening a steel flywheel, or at least having it balanced. Does one take the material off from the back side or does one mill the front were the clutch touches? I thought I read that one can remove about 2-4lbs from a stock steel flywheel.

They should remove it from anywhere they can APART from the clutch face, the ring gear and the crank mounting face.

Weight removed from the edge is "heavier" than the same amount of weight removed from the middle.

To give you an example of what CAN be done, these are flywheels for 2cv racing :-


1.8kg for the alloy one, 2.3kg for the steel one in the pic.
Standard is 6.5 or 10.2kg, depending on age...

[allessence]

Just run an alum one.

[idiot_saabvant]

Wish I could run an alum one, but funds have not been saved for that. But here is what I did do: Got my flywheel done yesterday. Here it is before milling http://www.saabphotos.com/gallery/album571/saabfw and then after (clutch side) http://www.saabphotos.com/gallery/album571/saabfw_003 and back side with weight removed http://www.saabphotos.com/gallery/album571/saabfw_001. I got 1.4 lbs off
and could have taken more, but this is what I bought ($125 US). It was also balanced, but I do not have a picture of the holes that were drilled on the surface that the timing marks are on. So this should really help with engine spool up and minimze harmonic vibration through the tranny and crank (which could rob hp)

pierre