Aprroximately what power increase can i see from say a set of March underdrive pulleys on an LO3. How much do they generally cost?

 

I have a set of them on my 92 L03 and March told me it would give me 10 hp. It might of. I could tell a difference,but i was hoping for more. I was told to buy the power and amp pulleys because of the stereo. They told me just the regular performance pulleys dont let your alt. start charging untill 2500 rpm. I paid $170 for mine out of jegs. They fail to tell you you will need a shorter belt. Also i had to turn up my idle because when i started my car it would die. It says in the instructions that u may have to adjust the idle. After i put them on i kinda wished that i would of got a pair of headers or something else but o well i guess it still adds some power. Hope that helps ya out.

 

If you are going to get pullies get the Hypertech ones. They come with a crank and alternator pulley. They drop only a little voltage off when all accesories are on but the seemed to add quite a bit of power.

 

Um, the March Underdrive Pulley's come with the crank and alternator pulley too.

I have a set, I didn't notice much. They just look nice and probably add maybe 5hp. Nothing noticable at my seat, but I look at it as a helper mod to the rest of those misc. mods u do. Like open element, spacer,chip, etc. They all add up. Just something to make u feel better.

 

Um I know that, The hyper tech is only two pieces. That way it causes no problems.

 

What problems come from a 3 piece March set then a Hypertech 2 set? If it comes with an Alternator pulley then ur gonna some light dimmage at complete stops. So if the set didn't come with an altenator pulley then I could see that problem being solved, but u said the hypertech set comes with the crank and altenator pulley, so the problem would still happen. I personally don't see a problem with it. Its not like it dims to where u can't see anything, it dims very slightly for me. Nothing seriously noticable or annoying.

 

Because Hypertech includes both the crank and alternator pulleys, they can control the speed that the alternator spins at all RPM's, even though the other accessories are now turning slower than they would with the stock pullies. The same can be done with a three piece pulley system.

Another advantage of underdrive pulleys is that if you modify the engine to rev higher, you can put on the underdrive pulleys and the accessories won't spin past their maximum rpm because of the pullies.

[This message has been edited by TonyC (edited August 07, 2001).]