i have already bought a stage 3 clutch kit with 8.5lb flywheel and an aluminum underdrive 1.5lb pulley, its on an 88 crx hf with d16a6 swap, ive heard it will mess ur crankshaft bearings up using and underdrive light pulley, if i do install both do i also need to install new crank bearings. can someone please clear this up...? i dont wanna mess my engine, its only got 60k on it.

 

From what I've heard, I know it throws the crank out of balance if you have a stock flywheel. But since you have a light flywheel I couldn't tell you. If you search I'm sure you'd find something.

Not to get off topic but why a stage 3 on a a6? Are you strickly drag racing this car?

 

The reason the undrives ruin the crank bearing is because they do not have a rubber dampner to absorb the vibration. So the vibration goes straight to the crank and bearings.

 

i've personally never heard of a lightened fly wheel mess anything up... but I know the pulleys do...

Its not really worth it IMO you will pick up what 5hp tops? and those 5hp are causing damage in the mean time? doesnt sound worth it...

and from what I know that fly wheels sounds too light...it will probally decrease performance rather then improve it...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nicks_jdmstyle_ef9 &raquo;</TD></TR><TR><TD CLASS="quote">The reason the undrives ruin the crank bearing is because they do not have a rubber dampner to absorb the vibration. So the vibration goes straight to the crank and bearings.</TD></TR></TABLE> I can get pictures of the rubber ring on the stock A6 pulley if you'd all like to see one.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dr_latino999 &raquo;</TD></TR><TR><TD CLASS="quote"> I can get pictures of the rubber ring on the stock A6 pulley if you'd all like to see one.</TD></TR></TABLE>

i have 3 D series pulleys in my basement. NONE have any sort of rubber damper on them. The pulley will be fine just make sure the pulley itself is balanced. you might have to take some material off one or more sides to get the pulley balanced i dont think the companies balance them i think that is the problem,

 

Just discussing about this today, not the playwheel but for the pully, he was saying the same, an unbalance pully can damage the engine.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crx Jimmy &raquo;</TD></TR><TR><TD CLASS="quote">i have 3 D series pulleys in my basement. NONE have any sort of rubber damper on them. The pulley will be fine just make sure the pulley itself is balanced. you might have to take some material off one or more sides to get the pulley balanced i dont think the companies balance them i think that is the problem,</TD></TR></TABLE>



You can see where the metal was drilled out for balancing, now that is just for rotational stability. What about rotational harmonics? Can you see where the inner bit appears to be pressed on? What do you think lies behind there?

 

mostly drag yes, when these other mods are done, will try to find a good t3/t4 kit for it, but dont wanna keep replacing engines cause a damn pulley.

 

When i was building my race block , i left the stock crank pulley because of the harmonic balancer, but i had my crank pulley balanced with my lower end.

 

That same rubber damper fell out my crank pulley on my old A6/Y8 mini me swap. It was trying to trash my timing belt and the cover over it, so i took the pulley off with the impact and it fell out like a crumbled up cookie, after that i beat on it constantly and it still ran like new and never had a problem with it.