Just picked up my first evo and I've been slowly combing through it. The boost gauge wasn't hooked up but I could tell it was running on low boost. I fixed the boost gauge and indeed it's maxing out at a whooping 7psi!

So the wastegate vac hose is ran right to the turbo. I assume the stock spring rate is low and that's the cause of the problem.

I also assume there should be a stock boost controller between somewhere... Can someone help me out? My guess is I should just get a MBC a between the turbo and wastegate but I would like to know how I'm supposed to have it stock.... Just for informational purposes.

 

Can anyone confirm or deny stock wastegate spring pressure as .7bar/10psi?

 

pretty sure the oem wastegate spring is ~11psi for an evo8.

 

I'm at 11psi (evo 8) with just the wastegate pressure. Here is a link showing the vacuum line hookup for the stock boost control solenoid. Looking from the front it is at the bottom right under the air filter. 2 vaccum lines and a connector.

https://www.evolutionm.net/forums/ev...-solenoid.html

 

Thank you for that!

It seems my gf has ordered a new hallman for Father's Day so hopefully ill be back at atleast stock evo boost here shortly. I feel like I'm driving a stock GSX currently haha.

 

Good luck. Hopefully you get it all sorted out and able to run the normal 18psi or so.

 

Thanks man I have the hallman in and im running 18-19psi nicely. Checked the turbo for shaft play when installing the MBC and it feels good.

I really let her rip last night on my way home and good lord does it sound good at WOT.