i'm looking at a set of underdrive pulleys at hughes engines website.

LATE UNDERDRIVE CRANK & ALT PULLEY SET
ALUMINUM UNDERDRIVE PULLEYS (30% CRANK / 25% ALTERNATOR)



now do they really make a difference in power or ?



i'm sorry if i sounds stupid be i have no idea my buddy with a 03 corba has them on his car i can feel a differnce in the car when i ride in it. but his car is light and has a big *** supercharger on it. my truck is a brick and weights 6700lbs

 

I had them on my Dakota, took them off due to charging issues, I would save your money. Or just go with a underdrive crank pulley, leave the stock alternator pulley on.

I doubt you'll notice anything, I didn't slow down when I took them off.

 

Is the alternator pulley also an underdrive? Seems to me, slowing the alternator by better than 50% would not be a good idea.... and charging issues would indeed ensue. I had thought that the alt. pulley would be SMALLER than stock, so it would turn it close to stock speeds with both pulleys installed? Anyone shed any light on this?

 

Does anyone make a kit where the alternator is kept running the exact same speed? Would having everything underdriven but alternator even result in anything noticeable?

 

Don't get a cheap one for the 360 engine because it is externally balanced and most of the cheap u/d pulleys are not balanced

 

Don't get a cheap one for the 360 engine because it is externally balanced and most of the cheap u/d pulleys are not balanced. Can't tell what type of truck you have because I'm on my phone

 

Harmonic balancer and driveplate/flywheel are balance critical, pulleys aren't. (except on the newer trucks, where the pulley is integral to the balancer?)

 

I bought these from mancini for the 5.9 in my Dakota...they were 59.00 bucks when I bought them, you can't use the water pump pulley unless you get an older water pump with a bolt on pulley, and they won't work with a newer in piece balancer/pulley.

http://chucker54.stores.yahoo.net/momabipuset.html

I'm going with a CSR electic water pump so I'l have to go back to the underdrive crank pulley for clearance.

 

I've seen 'em on different web sites -- but six ribbed rather than the stock seven. So if/when I go to do it I'm going to put a local machinist to work. I'm tossed up between making the crank, water pump, and alternator pulleys smaller versus making the power steering pump and AC compressor pulleys larger. It seems, though, that the latter would make more sense (if there's no reason not to do it) because the latter two parts have much longer lifespans than the former three.

Most folks report increased fuel economy and just a tiny little pinch of power improvement. I wouldn't go in expecting much by way of seat of the pants, except for a slightly fatter wallet at the end of the year.

 

alright so i'm geting the hint that i shouldn't buy them thanks for the info guys i almost ordered them last night sure glad i didn;t