pirate3

iTrader: (11)

I've been doing some research and haven't been able to come to any conclusion as to whether an underdrive pulley is worth it on an auto LS1 car. It will be a drag car so any extra power will be put to good use. Opinions?

lsx24

iTrader: (45)

I see no reason it should be different than M6. Usually frees up about 10 rwhp or so just like a ported tb, worth it.

SEB

iTrader: (12)

Everything counts

My best before Mezuire Electric Water Pump & Pully
7.47@91mph
My best after the Mezuire Electric Water Pump & Pully
7.22@94mph

That is 2 tenths. I don't know about how much RWHP I gained. But I could not feel a SOTP difference at all. But the timeslips told a different story.

Cop Car

iTrader: (14)

IMO not worth it. the pully is hard to get off, the aftermarket pulleys sometimes have problems comming off because they need special pullers. if you are doing a cam swap and have a couple of hundred dollars laying around buy one, but if not i wouldnt go out of your way to do it.

i rebuilt my motor completely out of my car and im going to use the stock pulley again, and im not going to loose sleep over it.

pirate3

iTrader: (11)

Even if you split them it's still a tenth and at least 1 mph per piece. Thats the differrence between an 11.00 and a 10.90 Good enough for me.

I had one on my 02 M6 and it picked up a solid tenth and 2 mph. Wasn't sure on autos.

SEB

iTrader: (12)

What do you have done to your truck to run 14s. I have a 02 thats why I ask. I have the 5.3 motor.

pirate3

iTrader: (11)

Ported/Polished tb, tb spacer, billet servos, electric fan, 4" mufflex off my 02 Z modified to fit(sounds bad ***), custom CAI, tune, talyor plugs, ngk's, all royal purple fluids, underdrive pulley, 160 thermostat. It would probably run better with a custom tune..just got a mail order tune now. and it gets 17mpg all day long.

http://good-times.webshots.com/photo...93785784WeQkDK

LebaneseShowoff

iTrader: (6)

U/D Pulley's are def worth it on an Auto, i have one on mine and can def feelt he diff.

Tainted

iTrader: (9)

if you ran out of better mods to do like headers and such then go for it. every bit helps

SEB

iTrader: (12)

Was the underdrive pully & fan worth it. I have heard you gain no power off a Elec Fan.

I run 9.80s in the 1/8 at 73 mph with a 2.3 60ft, I would like to add
Pully
Fan
TB Spacer
Ported TB

Can I use the Ported TB off my 2000 LS1 on my 5.3?

Raise

iTrader: (31)

i wouldnt f**k with it unless ur throwin a cam in. its a bitch to get off and a bitch to retorque down for the power increase. but if u will already have the stock one off, no reason not to. pullies basically free up horsepower by taking some load off the engine. aftermarket pullies are usually lighter and smaller in diameter, making them easier for the motor to turn.

pirate3

iTrader: (11)

Yes. The tb is the same as long as you are not drive by wire. I picked up a couple tenths and 2 mph from the pulley and fan. It also helped my mpg too.

JstALs1

iTrader: (5)

I put a set of ASP's (Crank and alt. pulley)on mine a couple months ago. I noticed a difference but havent had any track time yet with them. I dont think i would recomend the Alt pully though i have some charging issues with it.

SEB

iTrader: (12)

I am upgrading to a FAST 90 MM Intake & will have my LS6 Intake & my ported TB just laying around to sell or if I could put them on my 5.3 Truckl...

How much did you gain MPG with the Addition of the Pully & Fan.

I am going to do that next forsure now. I bet that Mufflex sounds pretty sick on your truck.