PDA

View Full Version : Ghetto dampener pulley?????

DDSR240
08-27-2008, 02:15 PM
I was searching for any homeade harmonic dampener but i couldnt find any. My question is this do you think it would help to use a layer of dynomat on the inside lip of a aluminum crank pulley..and before I get flamed I do know it is much better for someone to fork out the 450 dollars and get a real one but if dynomat dampens all vibrations wouldnt it be a good idea to use it,insted of no type of dampening what so ever?? And one more thing how would you make shure the pulley was still balanced with the dynomat?, Is there even a way to do that?
Def
08-27-2008, 02:49 PM
Say it after me... damp, damper, damping. Nothing is getting wet here.


To answer your question - no, Dynomat will do nothing to reduce the torsional vibrations in the crank. This is a torsional vibration, not a simple bending mode like your trunk vibrating from too much "phat bass." You need a mass rotating out of sync with the crank at its natural frequency, and the stock crank pulley has a rubber strip that allows this(and everything is tuned to give the system the desired response).
the head
08-27-2008, 03:16 PM
wow...right up there with running sand through your engine to hone out the intake and exhaust...pure stupid
DDSR240
08-27-2008, 03:21 PM
Sorry man it was just one of those "crack-pot'' ideas I tend to have but I understand they are torsional vibrations but they are started by harmonic vibrations thats why I thought it could help, btw we don't have hooked on phonics in south carolina yet LOL:keke:
burnsauto
08-27-2008, 05:44 PM
dynomat would just throw off the balance of crank anyways.

do it right, call ATI. fork over your money for all the R&D they put in, and enjoy.
Def
08-27-2008, 09:37 PM
Sorry man it was just one of those "crack-pot'' ideas I tend to have but I understand they are torsional vibrations but they are started by harmonic vibrations thats why I thought it could help, btw we don't have hooked on phonics in south carolina yet LOL:keke:

Harmonic vibrations just refer to vibrations due to the response of a system to an input, which is pretty much what all vibrations are when you get down to it.

Torsional vibrations refer to the system(crank in this case) involve the crank twisting back and forth. You need something twisting back and forth in the opposite way to counteract this at the right time.