Low boost till 3rd gear
9 Second Truck Club
iTrader: (17)
Joined: Sep 2006
Posts: 3,672
Likes: 9
From: Colorado Springs, Co/ Central, Ca
9 Second Truck Club
iTrader: (17)
Joined: Sep 2006
Posts: 3,672
Likes: 9
From: Colorado Springs, Co/ Central, Ca
This is what I'm talking about. The turbo flange that comes in some of the sts kits I have seen will screw you with a divided turbine housing like the 1.15 AR tnetics. To make it work right you need to cut down the divider and knife edge it. If your setup is this way it explain some of the back psi issue.
Look at the T4 flange in this sts kit you can see how shrouded off the divided housing would be with that style flange. They are intended for undivided housings.... Combine that with that with that small charge pipe, small turbine wheel, large CI, a few exh leaks and it all snowballs....
Housing in pic im my T78 1.15
Look at the T4 flange in this sts kit you can see how shrouded off the divided housing would be with that style flange. They are intended for undivided housings.... Combine that with that with that small charge pipe, small turbine wheel, large CI, a few exh leaks and it all snowballs....
Housing in pic im my T78 1.15
Just a quick piece of advice, BE CAREFUL, if you do infact have exhaust leaks, weather their is one bad one, or multiple little ones, either way,
When you take it out to test it, keep an eye on your boost
When you take it out to test it, keep an eye on your boost
9 Second Truck Club
iTrader: (17)
Joined: Sep 2006
Posts: 3,672
Likes: 9
From: Colorado Springs, Co/ Central, Ca
You should be able to tell by looking at the outside of the flange. If it's squared you will see the pipe merge into the square. If you pull the turbo I would knife edge the divider even if it's a square flange it will help. If it's round inside you need to mill it down 1.5-2". X2 on the exh leaks or milling the divider boost could go way up.
I had the same issues as you. The piping and intercooler were way too small for my set up. Had to run 22# of spring to get 12psi on the manifold too. I gave up and moved everything up front. Good luck
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
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
High back pressure and slow spool usually = cold exhaust.
It's going to have high back pressure no matter what with 400+ cubes and a tiny turbine wheel, but it should spool very fast. The 1.15 a/r isn't very big considering how small the turbine wheel is.
