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BMW CCA Member
Did you go back to the stock flywheel and clutch? I think I would.
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Originally Posted by rajicase
This.
Caprica Junkie
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My thought is that the ATI damper is now damping the crank vibrations that the DMF was damping -- i.e. I now have a tuned system again.
Hard to say whether I need to go back to DMF now or whether there is some residual vibration that is not being damped by the ATI damper. Plans for now are to keep the damper and LWFW for this season and reevaluate in the winter.
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-Chris
Member
The reason there is a damper at both ends is to evenly damp the vibration across the crank. Engines with bad harmonics can snap the shaft in half. Now I'm not sure if this is a demonstrated issue on E36s, but it does sound like your engine is more sensitive than some others.
Caprica Junkie
|m| (-.-) |m|
BMW E36 M3 Expert
yup ... it's not fun. But I think this was due to a bearing failure.
15337491_1561024160591300_5612849661269944632_n.jpg
Modulator
BMW CCA Member
I had an 8lb flywheel on my car and spun rod bearings after a couple years of autocross and DE's. Rebuilding with ati damper, keeping 8lb flywheel. Good to hear people have had positive experience with that combo
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That's impressive! Did you at least make a cool lamp or something out of the parts?
I can't say that I've heard of that sort of carnage from a bearing failure though.
Caprica Junkie
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Agreed.
I think what you are saying is -- the tried and true solution is to go back to stock DMF/clutch + stock damper.
S52s from what I hear have been known to break woodruff keys and oil pump shafts, etc from the poor harmonics which is exacerbated by changing the system (i.e. adding a LWFW)
The untested solution which I am using (but not currently symptomatic) is to do the ATI damper + LWFW. Per ATI - it is tuned for a LWFW, though obviously I don't know the specs of the LWFW that they tuned it to.
What is known is that the new solution is at least better than the (untuned) stock damper + LWFW combination, since there have been no more belt issues.
I'm just lazy to pull the transmission again and put a stock DMF back in, as well as pull the ATI damper and put the stock damper back on. I haven't driven it in a year and am biting at the reins to get to drive it again -- not willing to pay a shop to do clutch and damper work and not willing to have it down for the month I'd need to swap out the clutch/damper when I don't have a good reason to right now, especially now that summer is here.
If it gets through the summer with zero issues then I don't really have a good reason to swap it, though I may do so in the winter "just because".
Last edited by ThreeD; 04-25-2017 at 06:57 PM.
-Chris
|m| (-.-) |m|
BMW E36 M3 Expert
Nah, I have way too many busted parts already for lamps and stuff
The theory is that the bearing failed, cause the rod to seize, which caused it to bend/break, and it wedged on the side of the block. Put a hole right through the side of the block.
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Update:
I swapped to DMF a while back w ATI damper, issues resolved. So it was the FW. The car drove great for a good while until I sold it early this year (still miss it) - it got replaced with a S2000 which is now on Ohlins & square wheel setup. Totally different beast.
ANYWAYS... the FW had been sitting for a while but a friend wanted it so he took it off my hands and brought it to the machine shop to get balanced.
The JB Racing lightweight flywheel was 30g off balance on one side.
30 grams.
30 grams.
So...there we go. Lesson learned, doesn't matter how "reputable" the manufacturer (JBR, china, UUC, etc), get your aftermarket flywheel and clutch assembly balanced before install, or you will go chasing zebras like me.
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Last edited by ThreeD; 04-05-2018 at 09:52 PM.
-Chris
Member
RIP all the AC belts thrown and the timing chain guides.
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