Flywheel Weight????

[HandalE30]

hey guys, kinda confused, wanna know how much does the e28 m5/533 flywheel weight? some places they say 17lbs, some other 15 lbs, Jb says 16lbs ..... and how much does the m5 e34 weight? cause Jb says they weight 16lbs too and I was told they were lighter (about 13).
and last is the m6 and 633 the same as the e28s (guess they are) Thanks lots guys. want to buy one and dont know which one to go with on turbo m30. can never deside. :(

[Lurker27]

Mine was 17 on the dot

[HandalE30]

17lbs, on which flywheel? 533/e28m5/633/m6? or e34 m5? Thanks!

[wildstoats]

17lbs, on which flywheel? 533/e28m5/633/m6? or e34 m5? Thanks!

Just for the record the 533/e28m5 flywheels are the same. Same part numbers even. According to Pelican's website it would seem that the 630CSi (1977), 633CSi (09/81-1/84), and M6 (1987-89) share the same flywheel as the e28m5 / 533. And some numbers that I see tossed around quite a bit are:

e28 535: 22.0 lbs
e28 533/m5: 14.7 lbs

Another route is to take a stock e28 flywheel and have it lightened. I had this done with mine although I forgot to weight it before I put the engine back together (doh!). If you need more info go search around mye28. This topic has been beaten to death over there. Hope that helps.

Edit: I'm also pretty sure all e34 flywheels were dual mass which = heavy as a boat anchor and unable to be lightened. But maybe someone can shed some more light on this.

[Lurker27]

e28 early model 533.

14.7 is doable is they milled off the pressure plate rim area, but not with a lathe. YMMV

[lashtx]

I have one that I purchased off of a guy and it is 17lbs. It was suppose to be the M5/533 flywheel, I can not locate a part number on it to verify. However it looks like the pics of the m5/533 fly I have seen. Box was marked 17lbs from ups.

Kris

[HandalE30]

Thanks guys for the info :D ive been searching on mye28 but there seems to be the same dilema on flywheels weight!, think ill train my brain to see 17lbs when I see an early 533 flywheel, gotta agree with Luker, 14.7... maby milled off. what about the E34 M5 flywheel? does anyone know the aprox. weight? Thanks.

[Lurker27]

AFAIK the m5 flywheel isn't much lighter if at all. I wouldn't want much less than 1 lbs anyway - more mass dampens vibrations and makes more power, and it revs plenty quick. Drops revs quick too.

[weaksauce]

AFAIK the m5 flywheel isn't much lighter if at all. I wouldn't want much less than 1 lbs anyway - more mass dampens vibrations and makes more power, and it revs plenty quick. Drops revs quick too.

i'm going to have to disagree with this statement. the added weight of the flywheel doesn't make it more powerful. if it did we would all have 80lbs flywheels.

[Lurker27]

That's nice, go look it up

[weaksauce]

That's nice, go look it up

i am always willing to learn. please point me in the right direction.

If a heavier flywheel makes more power, then lets go extreme with the situation just for the sake of argument. If that was true, why wouldn't the F1 and road racing teams run a 100 lbs flywheel instead of ultralight and small flywheels?

A larger/heavier flywheel requires power (torque and HP) to increase it's speed or inertia. although it "stores" the power better than a lightweight one by keeping it's momentum, it will not make the engine "more powerful"

http://www.uucmotorwerks.com/flywheel/how_a_lightweight_flywheel_works.htm

http://www.europeancarweb.com/projectcars/0109ec_bmw_m3_clutch_flywheel/index.html

i did look it up. maybe you should too? Happy reading!

[Lurker27]

My apologies for the flippant response, but my point was that the engine needs some damping force anyway, so just as there is "too heavy" - there is "too light" as well.

I meant exactly what I said - that a heavier reciprocating mass will smooth out engine operation and experience marginally less parasitic loss, ergo, it makes more power.

Would I want to drive an 80lb flywheel in real life? Of course not. But I wouldn't want some hypothetical 3 lb carbon flywheel either...unless the whole engine was designed around it and damn this actually sounds unbelievably cool (they do it in supercar brake rotors now)

[Jonsku]

You can check all the part weights from www.bmwfans.info

Changing flywheel mass doesn't affect engine output, what it affects is the "response time", or "eagerness to rev"..