Does anyone know how low you can adjust the boost pressure on stock turbo with stock internal wastegate? thinking about running 9:1 pistons in turbo mpfi would like to run maybe 5 lbs of boost.

What would be the point? You may as well put in a non-turbo EJ22 block and strap a turbo onto it.

You can't really run lower than the stock wastegate spring pressure, unless you add on a spring pulling the wastegate open. I've done that for pulling the wastegate shut, the amount of preload you put on your axillary spring sets the boost pressure. Poor mans boost controller, but it works well.

 

Just run stock boost and a meth/water injection system. You're trying to get more power by going to the higher comp pistons, right?

not looking to make a power plant here, but I know that a air to air intrecooler will lower the pressure, also the threaded rod should be able to be adjusted or bent to lower the pressure. I will probably end up using the stock lower 7.7:1 pistons.

I have used a carb block with 8.5 compression running in stock form. I believe stock boost is 6 or 7 psi.

 

I believe ea81 carb is 8.0, ea82 carb 8.5, and spfi 9.0 (please corect me if i'm wrong)

 

I think you could just use 9.0 compression and run middle grade gas and do just fine

EA81 carb: 8.7:1

EA82 carb: 9.0:1

EA82 SPFI: 9.5:1

EA82 Turbo: 7.7:1

 

Off the top of my head. Pretty sure those are the numbers though.

 

GD

Not sure about the EA82 stuff (Except the T). All turbos run 7.7:1, all EA81s run 8.7:1.

Its difficult to get the turbo to boost less... however if you install an intercooler you will drop the overall pressure some.