hey guys, my tuner's tuning my engine but we have a weird difference.

When we don't use de solenoid and only run on the springs then we have a afr of 11.2, 0.6 bar on the intake.

When we turn on the boost solenoid and run the same pressure of 0.6 bar the afr is totally off! it's running 9.7's and making much less torque ofcourse. We can set it to 11.2 ofcourse but the difference is 30Nm.
It should be exactly the same unless something mechanical is broken.


Any ideas?


Setup is Pfab twin scroll manifold, twin scroll GT35 turbo, twin Tial 38's wastegates. AEM Series 2 EMS, 2000ID's injectors.

 

Do you have a built engine? What CR?

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So when you reset the fuel back to a normal afr it makes the same power as before you ran the solenoid at the same intake pressure?

 

sounds like there is some sort of trim working when the boost solenoid is activated. some sort of offset table that takes what is happening with the boost solenoid and then messes with fuel.

what stand alone you running? NM, just saw what you are running.

i'll look in the software see if i can find anything, but i bet its a trim or offset table relative to the boost solenoids offset or trim tables. IE, if the boost solenoid is trying to hit 11psi, and there is correction factor happening to do that, then it might be messing with fuel also.

just a thought. in my mind spring 11psi and boost solenoid 11psi should be the same AFR.

 

Yes it's built, CR is 9.5.


When it's running off the springs @0.6bar it's running 11.2 afr and 330Nm torque. When we then turn on the solenoid it's running 9.8 ish afr and 280Nm torque. Then ofcourse we reduce fuel so we get back at 11.2 but torque is still way less with 290Nm or something.

By the way, this is at 3500rpm.


We checked all trims/tables but nothing is messing with the fuel, that was our first thought as well. Ofcourse we could be missing something.

Could it be some sort of back pressure problem with the manifold?

thoughts here are the same, 11psi on solenoid and spring should result in exactly the same results.

 

Oh I forgot to mention, the spring pressure is 0.7 bar. But we're testing at 0.6 bar (engine dyno)

 

Hmm you have something very strange going on here. Can you check ignition timing with a timing light running with solenoid on and with it off? If it is at the same AFR and same ignition timing at the same load and rpm i don't see why torque output would change.

 

Well, for one, you are going to be chasing problems w the twin scroll turbo housing and the lower CR.

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Well we probably found the problem. One of the wastegates was damaged, really no idea how. The membrane was damaged and the cilinder didn't function correctly.

Getting a new one tomorrow (Tial mvs 38) so we can see what happens. We also installed a back pressure sensorplate.

 

need this:

http://www.t1racedevelopment.com/ind...ition-kit.html