Forscan graph diagnosis

[MrGPz]

Hi All,

Being new to the turbo, I am trying to get anidea of the way the turbo operates.

my attachment shows part of a Forscan scope that I saved.

So, I was travelling at 50ish and then floored the accererator till about 110.

the manifold absolute went up to 2.48v, not sure what pressure this equates to.

The Turbo kPa rose to 135kPa and when I throttled off at 110, the Turbo pressure rose to 162kPa, I expect this was due to the throttle lifting off, 

if ambient is 100kPa, then the Turbo was limiting to 35kPa (5psi) is this right? 

and then on overrun the Turbo pressure rose to 62kPa (8psi) above ambient. Is this normal?

I am saving various graphs to try and expand my knowledge and reason out how it all works.

 

hope you can steer me in the right direction and feel free to correct my assumptions. 

[JETURBO]

If it’s a B series XR6T then yes 5psi is full boost and there’s an allowance for overboost in the strategy for situations like what you’ve data logged 

 

everything looks normal there mate  

 

the cleanest way to get data logs really requires a Dyno but you can spend time on the street doing it. Try to replicate start data the same each time ( MCT/ECT/Run Time etc etc ) then select a high gear ( typically 4th gear on manuals and ZF and 3rd on the BTR 4 speed ) and run the throttle to 100% before the kick down “Detente”( this is the bump you can feel at 3/4 throttle depress) as the TB is WOT at this point and will let the engine pull through the RPM without dropping back gears. The point to this to replicate high load WOT for the engine and all parameters go to maximum essentially so the data recorded is of use and relevant

 

happy logging  

[MrGPz]

Thanks, yes it is a 2003 BA. I thought I'd added a signature with details, I'll try to add it again.

I haven't had it long and there were a few gremlins, which I'm slowly coming to terms with.

The next one is Error Code P2140. Forscan is reading a difference between pedal position sensors 2 and 3, of about 0.5v from idle to fully depressed pedal.

Not sure what to do here except try another pedal position sensor.

 

Glenn