I'm currently tuning a evo IX, and we are having some weird issue. The car on the stock boost solenoid always boosted 25psi. So we did a few test tried to drop wgdc but always the same thing, it boost 25 from 4000 to 7500rpm.

So i tought that maybe the wastegate is a 25 psi. but if i run a hose direct to the wastegate boost is kept to 17 psi. So i guess the wategate actuator has been upgraded but to a 17 psi.

So now we tried a grimmspeed bcs, and it is doing the same thing even with wgdc set to 0. it should run 17 psi . but it is running 25 psi all the way to 7500rpm. If i hook up the hose that goes in the grimmspeed to the wastgate actuator it boost 17 psi.

So now i'm really puzzled....

Also i know that the grimmspeed is working, if i increase wgdc it is increasing boost pressure. And i confirm that wgdc stay at zero via evoscan.

It seem like the solenoid is acting has a boost restrictor by some way. but it did the same with the stock one and even if i let the grimmspeed hooked but not plugged(energized) it is doing the same, just like if the wastegate actuator was a 25 psi.....
Anybody had this kind problem before?No boost leak.

 

[QUOTE=ddb;10416124].....So i tought that maybe the wastegate is a 25 psi. but if i run a hose direct to the wastegate boost is kept to 17 psi. So i guess the wategate actuator has been upgraded but to a 17 psi.[QUOTE]

The base pressure for the FP 18# actuator is actually 14#. The base pressure of the 25# unit is about 18#. So, the 17# reading that you saw is not that far off base. It is within one PSI. So, it probably is a 25 pounder.

I call it base pressure for a particular actuator when it goes full open at x PSI with the turnbuckle freely slides on and off the peg on the flapper valve's pivot arm. Yours was full open, or equilibrium, at 17#. this means that the valve was cracking off its seat a few PSI earlier obviously.

 

I understant what you are saying but why would it open full a 17psi if i plug the hoses direct.
And why would it open at 25 psi if it pass trough a solenoid.

On my evo if i set wgdc 0% i run wastegate pressure so i see 11-12 psi. If i plug the hose direct i see 11-12 psi. no matter if i run trough a solenoid or no.

Why do i see 8psi difference if i run trough the solenoid instead of direct.
That 's what is bogging me.

 

Sorry, I am not the right guy to ask about solenoid function. I don't know squat about the things. I use strictly MBC on my turbocharged vehicles. Wish that I could be more helpful though.

 

Thanks anyway.

 

I would suggest trying a MBC for testing purposes and see what happens.

 

I'll try that has soon has we can meet again.

The guy lives at 2.5hr from my place so we can't meet often. That's why i'm doing research and asking so that when he comes back i have somethings to check and test. Because now i'm really out of idea.