Underdrive Pulleys Sheared Anyone's Crank?

I am looking into pulleys, but I had a 3KGT-VR-4 and the unorthodox racing pulley ended up shearing my crank. Was a fun rebuild, but Im not in the mood to redo that operation anytime soon?

How are the underdrive pulleys working out so far? Anyone had any problems?

[mbtoloczko]

No one has reported any problems yet, but those stock pulleys have a damper on them for a reason as you found with your 3000GT. Flat sixes are not immune to torsional harmonics. There is a very interesting report on the internet of a guy with a Corvair motor that measured torsional strains with/without a harmonic damper.

People have reported that the pulleys do noticably improve acceleration on the SVX.

I think i will wait, and see if anyone snaps anything then i might test the waters with one.....

[svxfiles]

42500 miles with a 4.25 inch underdrive pulley with no problems, so far. ( stock is 5.25 )

i probably put a good couple thousand miles on a lightweight underdrive pulley before my tranny went south.. no problems, but i didn't notice very much of a performance difference either..

-adam