02'Z71ONDUBZ'

iTrader: (8)

I missed that you had the Roush, don't they have the pressed on pulley? Be glad your seeing 11lbs, you don't have an easy option to increase boost. Your gonna lose several psi with the headers and cam. LS7 lifters are good, but I wouldn't pull the heads just to put them in. Kooks are top notch. That cam would work but definitely wouldn't be my first choice, there are much better options out there.

Coban

iTrader: (14)

Don't throw more parts at something that is already messed up.

In order to diagnose an issue, you kinda need to have the specifics of your kit.

topperge

Sorry, I did most of my posting from my phone yesterday and wasn't as a real machine to cross reference anything. It is a stock Roush kit with the TVS1900 and a 3.3" pressed on pulley.

My truck is a completely stock 2009 Avalanche with the 5.3L engine and the 6L80E transmission. Stock intake and stock exhaust.

They first had the problems getting it to stay in 4th to do the dyno pulls. Since it is the 6L80E that is the gear they dyno in. They do the same on the corvettes they do. The guys went back and for with Ken Kelly for 2 days on why the transmission wasn't taking the commands to hold 4th. They tried to manually shift it and it still wouldn't hold. They zero'd everything out and as soon as they put their foot into it the truck would downshift into second and take off.

They then street tuned it on Saturday since they couldn't get it to hold on the dyno and that is where they found it is making 11lbs of boost, but to get the AFR in an acceptable range they had to back it down to 9 degrees on timing. That is when they stopped because that obviously isn't a good place to be. They feel that the stock cam and exhaust in the truck isn't allowing enough gas to escape causing so much boost to be made and having to pull so much timing out. That is why they are thinking of moving to a new cam and the long tubes. They said they normally see a car drop about 2lbs with the long tubes and the LS9 cam should help allow the gases to escape.

Like I said, they do a lot of ZR1s with a cam and pulley kit with their tunes. They already have a stock LS9 cam from a take out that they would give me. I really only wanted a kit to that would pick up 100-125 rwhp from stock. I have two other play toys that keep my wallet busy. I'm worried that by doing these upgrades I'm going to be nearing another 500rwhp monster and then I'm quickly into doing more trans work. This is supposed to be my tame daily driver.

Thanks for all the help guys. If anyone has any other thoughts now that I've given some more information I'd greatly appreciate it.

bud8fan

iTrader: (9)

we did put the ls7 lifters and a 6.0 cam in my truck when the roush was installed....on hot days my truck makes 8 psi and on anything below 60 degrees it makes 10.i think allen told me im running 24* timing with no other mods. there is no problem in yours making 11 boost prolly in cold weather.like the others say you need to get a tuner on the truck that knows what they are doing