Droptoplt1ta

Are there any underdriver pulleys available for the 5.3 LS4 FWD? I dont thing a regular LS1 UD pulley will work?

Any word is anyone is going to make them?

AlabamaGuy

iTrader: (5)

Haven't really thought about it. I know my major problem lies with traction, not necessarily power.

94ss06gxp

iTrader: (5)

good luck installing an underdrive pully if one is ever made

Sittingmongoose

iTrader: (1)

I would be EXTREMLY nervous about messing with out pully systems. They are extremly sensative as it is plus it is all on one belt system

Mels SS

iTrader: (1)

I have one on my GP for 5 years I love it one of the best mods I have done!!

Droptoplt1ta

Sittingmongoose I dont see what makes the accessory set up so sensitive on this motor..... also there are many vehicles that only use one drive belt

Sittingmongoose

iTrader: (1)

have you ever tried taking it off and putting it back on? cause i have a few times and its a bitch. Which grand prix mel?

williamGT

iTrader: (5)

He has it on his 3.1L 1996 GP GTP.

Sittingmongoose

iTrader: (1)

well thats y lol, idk it just sounds like something that will cause issues, and for what gains maybe 5hp?
but i dont know enough about them so i guess i am not one to talk

JDMC5

iTrader: (3)

they've been doing it for years on the LS1's. Its a decent gain too about 10hp.

neilownz

I would worry since the charging system sucks to start with.

bumpin96monte

Underdrive pullies are pretty common, and I don't see any reason why you couldn't run one on the LS4.

The big draw on many cars is that its an easy swap and relatively cheap. On the LS4's, the little extra difficulty in install would probably make them less popular.

You could always do an underdrive crank pulley, and an overdrive alternator pulley if its that bad- that way you could keep the alternator speed close to stock, and just spin everything else slower.

Mels SS

iTrader: (1)

My GP gained 11 HP with the pulley on the Dyno.

BadA$$

iTrader: (4)

I don't know why our pulley set up would be that sensitive...and how does the charging system suck? I have never had any problems with it. Also underdrive pulleys are nothing to be afraid of, pretty good power for the price and work. If there is one I want it!

JDMC5

iTrader: (3)

on the 3.1 or 5.3?

Mels SS

iTrader: (1)

On the 3.1

JDMC5

iTrader: (3)

wow thats huge for that engine. Well in any case thats pretty typical for an LS engine too.

Sittingmongoose

iTrader: (1)

so how do we go about trying this? would there be a company we can contact?

AlabamaGuy

iTrader: (5)

Why wouldn't a UDP from another LS engine work?

JDMC5

iTrader: (3)

not 100% sure but they are probably LS4 specific.

Man, I can't believe nobody is making parts for these cars.