#96215, "RE: How do I choose the right Wastegate and Blow off Valve?" In response to In response to 0 Jul-14-06 08:08 AM by rhui
Originally posted by Petri Im new to the turbo seen. I have the Star turbo kit and I think the wastegate and blow off valve (BOV) are set for 9 psi? I am rebuilding my motor and head, I want to run 15 psi daliy and 20-22 psi on high boost, I've heard off 38mm 40mm and 50mm Tial wastegates and I wanted to know, how do I know what size to get and will I need to have a different flange put on? Same goes for the BOV those have different spings right? And what spring whould I need for the boost that I want to run? What BOV has a low sound too it and later on can use to recirculate back into the intake side of turbo?
Heya, welcome to the turbo scene... it's a whole other can of worms.
Anyhow, with the star manifold, you pretty much are limited to what wastegate you run. It comes with a turbonetics deltagate, which as far as I know doesn't have many other direct bolt ons. The other direct bolt on wastegate is the Tial 35-38mm. Anything bigger and you'd have to relocate and drill the hole bigger on the manifold. Picking the right size... the more boost you run, the more exhaust gases there are. In order to combat boost creep (unwanted boost) that is the purpose of the wastegate. For 22psi, I think a 38mm will do just fine, but you can run a 50mm as well. They all come with 7psi springs.
The BOV doesn't control boost. It releases back pressure so you don't get compressor surge on the turbo. I'd get one that reacts quickly, vents quickly, and does not leak. I could care less about the looks or the sound. I currently run a tial BOV as well... sounds great and vents quickly and won't leak. As for recirculating, this one vents to atmosphere.
In order to control boost, i run an electronic boost controller, with the 7 psi spring in the wastegate. The EBC makes the wastegate see a different psi so that you can run higher boost. This can be achieved with a manual boost controller (a valve) or running a stiffer spring in the wastegate...
