I was thinking about getting an underdrive pulley for the new engine I am building for my 02 Z28. So I was wonder with the 25% underdrive pulley is there any problems with the alternator not charging enough? Or the engine running hot with the water pump running slower? Or is it harder to turn the steering wheel with the power steering pump turning slower? Does the AC not run as cool in the summer?

And where can you buy the shorter belts that you will need? And whats the best brand of underdrive pulley to go with. Also do you really get much HP out of it?



Joel

 

I've had my ASP underdrive on for 3 years with no probs. Don't have dyno #s for just the pulley, but the engine seems to run a little quicker. No probs with A/C, alt or PS.

 

i am using a BBK u/d pulley, but i have an lt1. i have heard that it doesnt show up on the dyno! but with mine i did a tenth and a mph quicker on avg at the track.
downfall is that with an already bad alternator i am having trouble at idle. sometimes it gets kinda figgity and stalls out!

 

We have been selling ASP LS1 pulleys for years with no problems. Just make sure you locktite the crank bolt to ensure it doesn't back out. If you get stuck in traffic a lot, go for just the underdrive crank pulley by itself instead of the crank and alternator pulley set. There are no cooling or power steering problems.

The belts are available at any local auto parts store and the sizing you need are included in the instructions. We recommend you keep an extra set in the car just in case you ever break a belt in the middle of no where.The ASP pulleys are SFI approved as well.

 

If you get stuck in traffic a lot, go for just the underdrive crank pulley by itself instead of the crank and alternator pulley set. There are no cooling or power steering problems.



i was under the impression that the crank and alt set was for when you needed extra charging for you alt? thus he overdrive alt pulley included in the kit?

 

No, the standard kit includes an underdriven alternator pulley as well ASP948584. However, we can get an overdriven alternator pulley by special order.