YES i know the light FW can cause problems when starting from a stop...
YES i know they are better for road race or autoX than for drag ...i don't drag
YES i researched this purchase before hand...


just wondering how the flywheel affected felt engine vibration? i would think it would increase to some degree.

but how much?

i mean 1/3 the weight is ALOT of rotational mass to not have soaking up vibration.

i just installed the Spec 4 on my cammed LS1. and i've only got about 30 miles of driving on it for the break-in. i'm getting an noted increase in vibration, high frequency and rpm related..not speed.

seems to show up at 2000 or so, but i did some slow rolls in 4th up to 90mph or so and it seemed to smooth out.
this makes me think it has something to do with the harmonic properties of the flywheel.

any guys with actual experience have similar encounters?

 

some one must have one of these flywheels


ttt

 

was the aluminum flywheel balanced?
was the original fly wheel balanced on its own, or with the rotating assembly?

 

it was a direct bolt on...so it should have been balanced.

funny thing with it is that it goes away after a certain rpm...or seems to

 

Ttt

 

Sounds like the FW needs to be match balanced to me.

 

^^^ Word. Sound like somebody is gonna be dropping their tranny again.

 

it's factory balanced...hard to imagine it was off.

i'm wondering if the FW didnt seat on the end of the crank the proper way

now that i know how to pull the trans...it's not a big deal...just a pain.

gonna get some more miles on it, see what happens, and how it feels in the upper rpms.

 

Any update on the vibration problem ???

 

still very mild...

i think it's just a side affect of the light flywheel, big cam, poly motor mounts and poly trans mount.

 

The poly motor mounts and poly trans mount, will cause vibration problems. Aluminum flywheels when balanced will not cause any more vibration than a heavier flywheel.

 

I agree. But it is concievable that a light flywheel might cause the motor to feel a little "rough" due to less torsional damping.

Rich

 

If my memory serves me correctly, it would only be at low rpm (due to firing pulses). Once the revs start to build, it should go away quick.

 

Yeah, that's what I was thinking also.

Rich