Twin turbo boost problems

[05chevy]

A buddy And I installed a 475 over stock twin setup with 60% nozzles. The truck has plenty of fuel. It will smoke till the turbo really light but will only make 40psi.

I tried opening the vane position from 35 and 1800 across the board. Thinking the small turbo might be choking the larger turbo out. Didn't really help at all with boost.

I don't think it would be a fueling issue. All though when after the turbos light and only get 40psi it is smokeless. Could the boost reference table be limiting fuel or could the larger injector nozzles be spraying more fuel then a limiter table calls for and is limiting me on the top end?

Thanks for any help.

[Motorzane]

Have you messed with the MAF table. You sensor is now having the air sucked across it from the bigger turbo.

[Dmaxink]

The issue is that it will take more fuel to
Drive the 475... Put around 2300uS in that tune and if the cp3 is healthy you will see close to 50lbs.

Thanks,
Kory

[05chevy]

The issue is that it will take more fuel to
Drive the 475... Put around 2300uS in that tune and if the cp3 is healthy you will see close to 50lbs.

Thanks,
Kory

I forgot to add that the egts will hit 1400* pretty quick. Will more fuel make this worse or will hit help the big charger light and bring the egts back down?

[Roc8man]

Are you reading your boost level from a gauge or on EFILive? If EFILive, the MAP sensor has an upper limit that will only show 40ish psi of actual boost. I have Twins and my gauge shows 50 psi but EFILive always tops out at 52.8 psig Total Turbo Boost -- 52.8 - 11.9 psia (I live at 6000 ft) = 40.9 psig If you're smokeless you should be ok.