npb4me

iTrader: (1)

Okay, my dad has a 2007 GMC Sierra 3500 with the 8.1 and an Allison. This is his 4th GM 3500 and this truck sucks. Power is horrible and as far as we can tell, the Allison is robbing it. With no Allison tuning, we are trying to decide on a supercharger, or a new motor. What would you all recommend, Whipple?

Spoolin

iTrader: (8)

I recommend swapping motors. I will trade you a 5.3L for that 8.1L

npb4me

iTrader: (1)

Your 5.3 would out run this thing.

ZZebes

iTrader: (10)

whipple makes one

Yogi Bear

Keep the 8.1. Get a cam, a blower, and a tune.

beastmode

iTrader: (52)

havent heard to many say the 8.1 sucks for power, my buddy loves his

npb4me

iTrader: (1)

I think it is the Allison tranny is slowing the truck down. Acts like the motor is trying to go, but it just isn't. The dealer says everything is fine with the truck to. His 2004 8.1 with the 40L80E had a lot more power.

How reliable is a whipple?

npb4me

iTrader: (1)

I am trying to convince him to go blower, long tube headers and to take off the Flowmaster muffler and try something else. He has a Flowmaster muffler and a K&N Intake setup now. Didn't seem to help much. I have HPTuners, and now matter what tune I write, it doesn't seem to improve very much. And I can't program the Allison because it has its own computer.

Zick

iTrader: (18)

Should have got the Diesel. Mine has no problem telling the Allison to shutup and go faster!

npb4me

iTrader: (1)

Trust me I know. I had a Duramax and it was great. But my dad being a truck driver his whole life, hates the smell of deisel. He says it makes him sick from all of the years he bathed in it. I tried and tried to get him to buy one. Damn stubborn dads.