sdm1234

iTrader: (8)

Just a quick question... If I get an underdrive pulley, do I have to get a new bolt, or can I re-use the old one? And how to I know what size belt to use afterwards? Does the pulley manufacturer say? Thanx everyone

mhayes2344

iTrader: (3)

Im pretty sure the march underive pulley set uses the stock bolts. As far as belt size, I have no clue. I bought the march overdrive alt. pulley and Im still trying to figure out how to determine what belt size I need.

sdm1234

iTrader: (8)

what did everyone else do?

the_merv

iTrader: (88)

You keep the same Bolts..there are 3 of them..
Then you Bolt the Balancer on the front of the Pulley.

You also will need a 60" Belt, the stock length is 64"

speed_demon24

iTrader: (6)

Don't get a POS piggy back pulley, get the asp 23% underdrive pulley. It's a real underdrive pulley that replaces the stock pulley. And you just re-use the stock bolts, but you will need a shorter belt. And don't expect to pick up much power with a pulley since lt1's don't have a belt driven waterpump like LS1's.

95CamZ

iTrader: (3)

I'm about to get underdrive pulleys myself and the only thing holding my back was the same question what belt size!!! Thanks for postin this! N where did you get your flamethrowers from b/c i've have been trying to get a kit as-well??

sdm1234

iTrader: (8)

Would it be better to get a 25% underdrive or a 34% underdrive? I found different manufacturers which make both. I don't have a special audio system or HIDs or anything... Would the 34% be more beneficial or will that damage anything?

sdm1234

iTrader: (8)

Will a larger percentage affect anything like the charging system or something?

That_guy

iTrader: (1)

lol i hear it messes with your amp gauges or something but im not sure.

96capricemgr

iTrader: (1)

Stock cam and charging issues are likely, with a bigger cam and accompanying higher idle it should be fine.

Like speeddemon said though don't expect to gain much, frankly I would go a step further and say don't bother.

TXFORMULA

if you had an electric waterpump you might pick up a few horses from the pulley... ive heard claims of 10hp from switching to an electric waterpump...im going to try it

96capricemgr

iTrader: (1)

What are you talking about?

If anything the extra electrical load of an electric WP would make charging more of an issue with a pulley, will have no cumulative effect on peak power but might contribute to idle charging issues. If you think I am wrong argue it with science.

Far as electric WPs they use much less power than mechanicals because they move much less water, seeing as the stock pump only consumes 11hp at 6000rpms a 10rwhp gain is unlikely with an electric, more like 6-7 at the wheels is normal

dhdenney

iTrader: (53)

Yeah I noticed a charging issue with an underdrive pulley. I scrapped all that junk when I rebuilt the motor. Something I thought about reading this thread, I have the 1LE a/c delete with little pulley..... I guess it underdrives the PS and alt too. No charging issues though cuz my idle is higher than stock.