Flywheel Lightening - How much to take off?

[winstontj]

Shortly I will be sending out a flywheel to be lightened. (It's the 215mm one) How much should I ask them to take off? I've heard that the S14 crank is 9lbs heavier - but the weight is very central so it won't feel heavier than the stock crank. Should I aim to loose 9lbs? I can tell them anything - 25% lighter, 9lbs lighter, etc.

Does anyone know how much a stock flywheel weighs vs. how much an aluminum one weighs? Also is this dangerous at all? I don't need the ring gear part breaking off at 6 grand and coming up through the floor.

[c.d.iesel]

Where, and How will your car be used/driven?....please read link

http://bimmer.roadfly.com/bmw/forums/2002/search.php?st=flywheel+weight&dosearch=Search%21&ps=20&m=natural&o=default

[winstontj]

Thank you for the link CD. So 25% of ~19lbs is ~4.75 and I was hoping to get between 5 and 5 pounds shaved off.

Dual purpose / HP street only car. Not a race car. It's also going to be a stroker motor if that makes a difference. E21 "log style" intake, megasquirt, 9.5:1 CR. Hoping for a nice grocery getter/possible auto-x car but not a track car.

I'm willing to compromise a lot - I have urethane bushings, plan on a booster delete, etc. So I don't mind if it revvs a little higher or if it's a little harder to drive - but I don't want anything crazy like a true race car. I'm looking for some form of moderation... if I can

[TJW]

A look at what can be done

[winstontj]

A look at what can be done

TJW... first of all I've seen your car and although I envy you, I don't have a full race car like yours. How much weight did you take off and what clutch is that? I have a feeling you'll reply with something like 5" solid 4-puck.

I'd love to do that but isnt it a little much for a DD?

Thanks for the pic!

[TJW]

Actually it is not on our car, it is on a friend's e30 M3 and I don't know the weight of it, I posted the picture to show what can be done, info value only.

Oue car runs A JB aluminium flywheel 8lbs from memory and drivng around the padock is no problem, pull away in first at 1200/1500 rpm no problem.