Turbo actuator boost to high.

[choppyspin]

I have a 4agze in my ae86. I have removed the supercharger and now has a t28 with a internal wastegate.I need to get tuned becuase Im using a haltech ecu now and the turbo set up is new. The person who I'm getting to tune it said he would like to have it running around 10 psi and then wind it up with a controller slowly to a safe boost/tune. My problem is I can't get the boost lower then 15psi. I got a new actuator and tested it before installing it which was opening at 5psi fully open at 10psi. But installed it still runs to 15psi i adjusted the rod but no difference. Dose anyone know why this could be or dose anyone know of any other way to lower boost?

cheers Nathan

[jaz_ae86]

have/had this problem on my boosted 4AG. Basicly you are flowing more air than the wastegate can pass.
Making sure that the wastegate flap opens FULLY is critical, this is a function of the the start point of the actuator and the angle of the rod to the waste gate.Stroke of actuator aslo important.
Also, taking the exh housing off and porting the wastegate port is good idea to remove any dags.

I got my boosts down buy re-mounting the actuator to ensure the flap opens as far as possible. Porting made little difference.

This is a problem also on SR20, you can buy/get made/make larger wastegate flaps and get the passage machined larger.

Having said that. 15PSI on a GZE is easily done, your tuner will just have to be more careful early on checking for detonation.

Expect OVER 160rkw with decent exh and intercooler.

[R&D Mechanical]

keep it on 15 like me and just run 200kws its safe and easy

[Sam-Q]

might a split dump pipe with a seperate privision for the wastegate help?