Overboosting problem..
 

I am having a strange problem with over boosting on my new turbo setup. The engine is a 5.3 with a sloppy stage 2 cam and a GT45 turbo with 44mm wastegate, 3.5" downpipe.
On my first dyno session I was hitting around 12 PSI at 3800-4000 RPM and I only wanted to run max around 8 PSI.
So I took it home and installed a lighter spring. Next session I was still getting up to 14 PSI at 5200RPM, so just out of curiosity I removed the spring completely and I still got to 10 PSI at 5800 RPM which doesn't seem right at all.

I ran this turbo/wastegate combo before, but with a different header/crossover setup and didn't have issues.

Is it just a wastegate location problem? It seems to move smoothly by hand. Would it work better if I welded it to the turbine housing?
Any advise would be appreciated.




https://cimg9.ibsrv.net/gimg/ls1tech...9d9834a68f.jpg
https://cimg0.ibsrv.net/gimg/ls1tech...e7f0f3f4a2.jpg
https://cimg1.ibsrv.net/gimg/ls1tech...68c5577350.jpg

Priority isn’t ideal IMO. Is there a reference line to the bottom of the gate? Looks like the hose is cut off just before the clamp. If so, put a line on it from the compressor housing.

Reference is hooked up, picture was just a old one from mock up. Here is a current one



https://cimg0.ibsrv.net/gimg/ls1tech...ab7b697860.jpg

Explain how your reference line is hooked up. Looks like it’s going to a solenoid.

So no spring in the gate and a reference line to the bottom (not the dome) and you still made 10 psi? Put a rag in the pipe off the gate and make sure the gate’s opening. If it is, move it. If it’s not replace it.

For anyone else reading this. For a cheap overboost protection, pick your max boost and about 1 psi above that, add a bunch of fuel. It has saved my motor a few times doing this. Youll feel it nose over and lose power. Its up to you now to let off.