notinuse

What do you guys think of this one? ATI 25% underdrive pulley. I'm looking for quality damping over underdrive but it is an ATI. Do you think some dampening is sacrificed for the smaller diameter? ATI 918844

vettenuts

iTrader: (4)

I spoke with one of the ATI engineers a number of years ago at Corvettes at Carlisle. He told me that anything more than 10% would sacrifice the damping capability. It sounds to me like ATI caved to market pressure of selling a 25% reduction. I am running their 10% under drive on my car.

JakeFusion

iTrader: (7)

I'd go 10%. You want the damper to dampen.

wildcamaro

iTrader: (15)

Stock size would provide best harmonics and avoid any other issues associated with under drives, but 10% is no a huge deal, I wouldn't run a 25% even though many out there are.

dr_whigham

iTrader: (49)

Bingo. I ran a PowerBond with no issues (25%) but if I could do it again, it'd be an ATI 10% all the way. My car might have seen the 6800 redline once a month, so it didn't bother me. If you have the funds, definitely an ATI 10%

notinuse

Thanks, looks like it's the ATI 10% for the win.

Pharcyde50

iTrader: (11)

Running the ATI 10% here. Car runs great to a 7k redline. Though I ran an ASP 25% in the past with no issues. I thought the ATI might be worth a few hp to hit my 500 rwhp goal.