To Underdrive or Not To Underdrive

[SlammaDingdong]

Based on marketing claims, underdrive pulleys (crank and alternator) seem like a pretty reasonable "dollar per power" mod. For instance, ASP states 12-15 HP for their "GM Street Pulley".

This is a mod I've been looking at, but am still somewhat skeptical. Check out the following link:

Interesting Test Results (Please Don't Flame Me)

I realize these results are based on a 4-cylinder Saturn (a good car BTW), but you can extrapolate the numbers. Most importantly, I'm not intending to bash any after market pulley makers, just trying to get some feedback.

Assuming there is some power to be gained here, what about the long term effects on the belt driven components? For electric power issues you can obviously upgrade to a higher peak output alternator. But, for example, there's nothing you can do about decreased fluid flow in the power steering pump.

I'm leaning towards saving my $$$ for a cam kit.

Are underdrive pulleys a or a ?

[Luke2kz71]

i wouldnt use a pully.... they dont give u that much power really...

if you have a stereo system, your alt wont spin as fast, so yopu may not get voltage numbers.... also your vehicals wont stay cool as easily on hot days when your at idle. which really sucks here in texas. then the a/c ....

i just dont think it is woirth losing all that, and spending $250 just to get about 10-15hp

[LS1Nica]

I read alot of those chevy, PHR and GMHP magazines and they are always doing bolt ons to LS1's, you probably got a 5.3 but it should be around the same results. They dynoed 9HP on the average and about 8 LBS/TQ. So for $200 I think I rather go for some gears or some of the earlier bolt ons. A cam is a good choice but I wouldnt get one without headers cuz they are like peas and carrots IMO. Good luck thought and welcome to the board to the both of you.

[LS1Nica]

Oh man I didnt even look at your sig, im sorry. It looks like you already got all the lil stuff out the way. If you already adressed your traction problems then I would go for the cam kit instead . Just carefull which cam, just in case you want to FI later on.

[NITROUS]

I've got a Hypertech Power Pulley and I'm not that impressed with it. I guess it helps with all of the other mods but not very noticible without dynoing.

[Hit Man X]

7-11rwhp is about all you'll see if you don't overdrive that alt which I DO NOT recommend. You'll have no charge at idle. I've seen them dyno'd to do that... run a truck beltless, you'll see a LOT more power gained. That PS pump saps a lot, so does an alt at full charge.

Too bad the dampner is part of the pulley, $200 is better spent toward some full length headers or e-fans.

A locked fan clutch will sap nearly 17rwhp from you I've seen...

[SlammaDingdong]

Thanks for the feedback ya'll. Looks like my bucks are better spent elsewhere. I was leaning that way to begin with (NO underdrive), but it's nice to get other views.

[kirkrhughes]

I’ve heard that our computers are power hungry, uh, female dogs and if they don’t get enough juice they can act up.