pornstar68

hey just wondering what info you guys have on underdrive pulleys are they worth the money

lilstephsls1

iTrader: (5)

yes

Gloveperson

iTrader: (9)

Yes and Yes.

They will get you about 5-10 RWHP freed up from the drivetrain. It is a very easy install and there are pretty much no drawbacks.

BTW, interesting S/N....

pornstar68

thanks

2MuchRiceMakesMeSick

For the money there are better gains IMO. This is assuming this would be your first mod? LS1s really do good from a free flowing exaust and intake. Then I would say cam. After you get those you can start working on supporting boltons

FroDaddy

iTrader: (1)

yup and yup. I had the stock pulley with my heads/cam/ bolt-ons setup, but just finished installing and testing my underdrive pulley tonight. I could tell the engine revved much faster when free-revving at idle. the car seemed to pull a little better, too. I'm sure the gains would be more noticable on a stock internal LS1

BlkZ28LS6

iTrader: (1)

I am also interested in this topic, but before buying, it's good to ask questions: Can underdrive pulleys cause the car to run warmer since it slows down the water pump? Are all aftermarket pulleyes perfectly balanced? If they aren't could they cause knock retard? Do they help M6 cars rev more freely? And from reading threads I've seen quite a few people having trouble with installation (getting bolt out/stripping it). This is all I could come up with. Not trying to hijack the thread, just trying to come up with specific pros and cons. Thanks

Martingale

You guys using the stock belt with the underdrive crank pulley?

ZR2877

If your car is stock or close to stock you should start with a lid then do headers,exhaust,and the other little stuff then when you do a cam do the pulley at the same time. What year is your car?
Ohh yeah the pulley is a great mod to do.

2MuchRiceMakesMeSick

Nope. Different size belts. Theres a group purchase going on if anyones wants to get one at a really good price.

Fast Eddie's 02 T/A vert.

PROS: I was very happy with the power gains after the ASP pulley was installed.

CONS: My car is now very hard to steer at idle speeds while trying to park. It's so bad that I have to use all of my strength to turn the wheel in tight spots, my wife is not happy about this.

I'm going to have the idle increased a little and maybe try another pump. Other then that it's all good.

Lithium

iTrader: (47)

I got the ASP pullies. I felt a slight differenece in power, and really like them. I have had no issues with them at all. But as said before, save this for later. Money can be spent better else where.

ULTIMATEORANGESS

iTrader: (4)

for what they cost pullies are worth it.


it was one of my first mods because i got a great deal on a crank pulley setup complete for $180 shipped.

red99vette

Who has the group purchase going on for these? I am interested in one for a 99 Corvette. Kaley

Gloveperson

iTrader: (9)

Just check the group purchase area of the classified section of this forum. If there isn't one going on now, there probably will be anytime soon. These are a very popular item in which a group purchase is common.

2MuchRiceMakesMeSick

You quoted the wrong person

Group purchase is here
https://ls1tech.com/forums/showthrea...=277653&page=1

lilstephsls1

iTrader: (5)

just purchased mine yesterday babyyy

TheBlurLS1

iTrader: (8)

you will also need a new A/C compressor belt with the ASP pulley as it underdrives it as well (as i understand).

you can also order an underdrive alternator pulley, which isnt recommended if you have a huge stereo or somthing. how is it running one with all stock electronics?

Another_User

Add Redline Watter Wetter when you add the pulleys and you won't have to worry as much about increased heat. Water Wetter really does work. It also helps to add a little more water than coolant, if you live in an area that does not get too cold. Water is better for removing heat from your engine than antifreeze.