Only 10psi of boost after turbonetics turbo upgrade please help!

[Spooling supercrazy]

New to this site but have seen many people on here get the help they need so here's goes, I have a 85 hot air gn. I just upgraded to a bigger turbonetics turbo with a 3 inch compressor wheel and a 2.25 exhaust . I just rebuilt the turbo and bought a new backplate with a carbon seal for it as well. I was boosting 15 lbs before on the old worn garret but now its at 10lbs with the upgraded turbo.i modified the old waste gate bracket to work but it doesn't move at all when I rev it in neutral as it did before on the garrett. I've tightened the rod but no change. Does anyone know whats going on? Can anyone help?

 

[Wahoo]

How did you balance it?

 

[Spooling supercrazy]

How did you balance it?

I marked the tip of the shaft also the nut and impeller . Put it all back. Doesnt sound like a cop car or anything. Spools fine but stops at 10 psi. I have tried to adjust the nut on the wastegate rod but doesn't seem to matter . I put the original down pipe flange or discharge elbow on it. I still am using the original down pipe.The puck inside moves freely and I have verified that it does make a perfectly centered contact. I think my wastegate solenoid might be at flat but not sure. The ses light comes on sometimes but goes away but it done that before with on boost problems with the original turbo. The actuator doesn't move if I rev the engine like it had before.

 

[notacarlo]

It should not move when you rev in neutral....which is never a good idea. Disconnect the waste gate and see if the arm moves freely. It would probably be a good idea to replace the worn out gate with a new turbo. If you are only making 10 psi I would suspect a leak somewhere in the tubing to and from the gate. Double check all the lines. What does the engine show for vacuum at idle?

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[Spooling supercrazy]

It shows 15 for vac . Checked all hoses. They all seem in their proper place. Just zip tied the main wastegate hose but don't think that's the problem

 

[milehighttype]

try adjusting with an Manual boost controller. If that doesn't change it, something is wrong. If it does, a larger turbo means its more efficent and its a larger area on the same setting as the stock smaller turbo, so that setting or a little change on the waste gate rod won't bump the boost up enough to account for the larger amount space in the turbo. I know this drop in boost happens when people do higher flowing performance heads all the time, and my thought is turbo size could have a similar effect. Like I said I'd try a manual boost controller and see if that works.

 

[turbonut85]

Still got the cat converter on it?

 

[Spooling supercrazy]

Still got the cat converter on it?

I still got the original cat on it and will be taking all that off soon when I upgrade and fab my own 3" down pipe. The boost controller is a good idea. I was able to tighten the wastegate rod further than with previous original turbo. Got it to 13 psi. So I guess it was the rod adjustment. The adjustment seemed to change from previous thought. Thanks for the help and ideas! I will be posting pics of my intercooler conversion soon. Came out very nice and used an evo intercooler

 

[turbonut85]

I still got the original cat on it and will be taking all that off soon when I upgrade and fab my own 3" down pipe. The boost controller is a good idea. I was able to tighten the wastegate rod further than with previous original turbo. Got it to 13 psi. So I guess it was the rod adjustment. The adjustment seemed to change from previous thought. Thanks for the help and ideas! I will be posting pics of my intercooler conversion soon. Came out very nice and used an evo intercooler

I'll bet good $$$ that cat is plugged and is your problem. At the very least...take it off and gut it...I'll bet your boost goes WAY up.