mvvette97

iTrader: (18)

or is it more for show? I'm not looking to see numbers go up on a dyno but rather just be able to feel the power. So can you even tell any gain with the butt dyno?

01ssreda4

iTrader: (96)

my car lost close to one hundred pounds pretty close to the time i put the pulley on and it did seem a bit faster up top. it could have been the combination of the two though. also, my car had hell idling after the install so im assuming the reduced load needed some compensation. a clear indication of a lighter load at idle which would mean a lighter load driving. also, i have heard they are worth about 5-10 hp. prolly similar to running w/o your AC on as opposed to with it on.

mvvette97

iTrader: (18)

What kind of idle trouble did you have? Was it something that just took some time to learn out or did it take tuning?

01ssreda4

iTrader: (96)

^^^^yeah exactly. i had to feather the gas pedal to keep it running for five minutes or so. then shut it off then crank it back up and it got its **** together. no biggie. did the same thing when i swapped out the stall converter for one that was twenty pounds lighter. it throws the idle off but it will figure it back out.

omcar

iTrader: (10)

do it..every little bit helps...see sig.

HASTINGSRJ

iTrader: (18)

I saw gains with my pulley. But then again, it would spin off when I sprayed N20, if you put a pulley on a good idea is to do a pin kit with it, just for some added insurance....

teke184

iTrader: (5)

i never felt anything SOTP

but the engine did rev up faster, which says something.

in reality you're never gonna feel 5-8hp...hard to even see it at the track unless you are REALLY consistent.

Gregory

iTrader: (4)

You'll see the difference in your voltmeter. Otherwise the under-drive pulley really doesn't help until like 3500+ RPM per the manufacturer seller web site charts.

HASTINGSRJ

iTrader: (18)

I dyno'd around 10 hp and tq difference(lower) when I took my underdrive pulley off my car!

405HP_Z06

iTrader: (11)

A quality one is worth a little, but nothing to write home about. If you install one make sure it's an ATI. Peruse this thread about after market dampers and the connection to broken timing chains.

https://ls1tech.com/forums/generatio...n-failure.html

01ssreda4

iTrader: (96)

^^^god i guess they are all gonna get a bad rap now that that thread has come out. lots of people have been running UDs for lots of miles with zero problems.

devinfbody

iTrader: (4)

I just got done reading that whole thread an hour ago. I'm glad i found it because i do plan on road racing my car, im def going with an ati unit now. It's worth a read for anyone looking into an underdrive pulley.

HASTINGSRJ

iTrader: (18)

I had 2 ASP pulleys and they were garbage. Kept walking off the crank!!! Everytime I sparyed N20 at the track. I replaced the crank bolt 4 times!!!! Finally got a pin kit, but pulled the motor before I put it on.....

Grimes

iTrader: (3)

Yeah, there are SO many ASP pulleys out there with zero problems. Mine being one of them. It's been like 70k miles on mine.

Some people who mod are bound to run into problems, that just the name of the game.

HASTINGSRJ

iTrader: (18)

exactly! But stock sucks so I will mod

69_YENKO

iTrader: (16)

I had an ASP on my 10.8 car without any problems (even when spraying the 175shot) it did rev quicker afterwords but i did the cam at the same time so who knows? lol

I just bought another ASP for my SOM car but I havn't installed it yet. im debating on just waiting until I do the heads and cam in a month or so

Intercooler2

iTrader: (24)

I will keep tabs on my Summit but looks like a quality piece. So ASP huh? That's the popular one here. Wonder if more of the failed ones were people doing cams where maybe the setup wasn't perfect.

waterbug1999

iTrader: (3)

I put my ASP on when I did the top end rebuild 3 years ago... No issues at all.