Not making power under boost
Thread Starter
Teching In
Joined: May 2014
Posts: 13
Likes: 0
From: Colorado Springs
Not making power under boost I'll be listing my specs below. Let me try to be descriptive as I can. Everything runs fine with my GTO. No driveability issues, no weird noises, good oil pressure and everything else is mechanically sound. Got a remote tune so the car can drive on its own to the Dyno shop. Remote tune guy got it running fine but I felt like it didn't make the power under boost like it should and the tuner agreed. But I thought for sure the Dyno shop would figure it out. Dyno shop tuned the car and they also agreed it wasn't making the power that it should under boost. From what they told me is there's not enough air flow under boost. The tuner keeps telling me that there's a "mismatch" combo either the turbo or the camshaft. 🤷 He also stated air flow is almost the same from no boost to 13# of boost. He saying everything with the tune is fine and spot on that it's a parts combo issue. The previous owner that built the car ran 10.6 which I was there in person to witness. He was at sea level and I'm at about 6,000 above sea level but I doubt that's the issue. I'm asking for people's input before I start throwing parts at the car. I am also willing to send a data log of some wot pulls. I'm hoping I'm making sense of things. Thanks for any help
2004 GTO
LM7 5.3 SBE
E85Holley terminator x ecu
Elgin 1840 sloppy stage 2 cam with supporting mods228/230 duration @ .050” with .585”/.585” valve lift and 112 degree lobeCleaned & flowed deka 80# injectors
Ls1 intake
853 heads
VS racing gen 1 7875 turbo 44mm gate @ 13#
Br7 spark plugs .026 gapped
Fast spark plug wires
4l80 with 2800 converter
2004 GTO
LM7 5.3 SBE
E85Holley terminator x ecu
Elgin 1840 sloppy stage 2 cam with supporting mods228/230 duration @ .050” with .585”/.585” valve lift and 112 degree lobeCleaned & flowed deka 80# injectors
Ls1 intake
853 heads
VS racing gen 1 7875 turbo 44mm gate @ 13#
Br7 spark plugs .026 gapped
Fast spark plug wires
4l80 with 2800 converter
Last edited by Franco Sj; Mar 9, 2022 at 07:03 PM. Reason: To add details
Thread Starter
Teching In
Joined: May 2014
Posts: 13
Likes: 0
From: Colorado Springs
So it's not making the power you think it should be, you don't have any idea how much power it's actually making, and you post no data. We're supposed to help you how?
Last edited by sewerpickle; Mar 9, 2022 at 08:18 PM.
TECH Fanatic
Joined: Jan 2022
Posts: 1,034
Likes: 468
From: Seattle
^^^^ yeah, kinda gonna be hard to offer any advice if we really don't have any hard data.
a cammed 5.3 with a 78mm compressor wheel even with stock heads stock intake manifold and a decent tune should be deep into the 600's for BHP.
a cammed 5.3 with a 78mm compressor wheel even with stock heads stock intake manifold and a decent tune should be deep into the 600's for BHP.
I don't see anything that stands out in what you listed that would be "mismatched".
That combo outta put down somewhere in the neighborhood of 500-550whp through that 4L80.
Its nice of them to have not charged you but how are you supposed to gleam any info from the session without the graph?
You are gonna lose a little due to altitude but perhaps its making power but just not what you were hoping for?
That combo outta put down somewhere in the neighborhood of 500-550whp through that 4L80.
Its nice of them to have not charged you but how are you supposed to gleam any info from the session without the graph?
You are gonna lose a little due to altitude but perhaps its making power but just not what you were hoping for?
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
