LT-1 underdrive pulleys

[TerryD]

Anyone swapped out the stock alternator and crank pulley with an underdrive units?? I've seen 'em in Corvette Centrals catalogin steel and in the Summit racing catalog for half as much in aluminum(It only specified them for LT-1 Camaro's and Firebird's(what's the difference??)
Terry D

 

[Chick]

Oh yes and it's worth a realistic 5 to 7 horse power. I've done a number of them and on my 89 vette I have a 3 pulley 'auto specialty system' and seen 2/10th increase in the quarter mile time.
Be warned your alternator does not charge well at idle.

 

[TerryD]

Since re-installation of the stock pulley requires it to be in a the same position as before(balance issue??), what's the deal with installing new underdrive pulleys? Will there be any reliabilty probs? Also should I go with the aluminum or steel(about $100 vs. $230)

 

[TerryD]

Anyone???

 

[Vettelt193]

Save your money, get the cheaper of the two. Aluminum should actually be better in my opinion. Reliability of your components (alternator etc.) should actually increase, because they won't turn so fast.

On LT1's there isn't a balance issue because the stock pulley with the harmonic balancer is relocated outward of the new underdrive pulley. Basically you will use both, one to balance and one to drive the accessories.

 

[Raysur]

I'm selling a ASP pulley in great shape for '92-'96 LT1's. I never got a chance to install it. I also have the belt for it too. I was asking $100 shipped for both. I have pictures if interested. raysur@usa.com

 

[Raysur]

http://www.aspracing.com/