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Link G4X running lean with hot start + unstable idle (subaru impreza V8)


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Hoping to get some help from the guys that are very known with link g4X V8 subaru Impreza.


own a fully build engine blok 2.1 stroker.

had a V6 subaru before with almost the same setup, that was tuned on a dyno.  No i m having the same engine in a V8 subaru with bigger cams 272 and new series Garret G-turbo did a conversion V6 to V8. the issue when starting the car was idle properly, this turbo is smaller then my last one, but flows simmular when driving and with the bigger cams it was way off at idle. Also the idle actuator is different on these models. V6 uses a steppermotor and a V8 a idle solenoid

same intention as last time running the engine in for 1000km and had 20 min breakin for the cams at 2000rpm. after that it is going on the dyno again.  Got it so far that the it idle ok for now exept the needle is not stable enough in my opinion... maiby it is the cams but that's where i want the help/sollution if possible. The other thing is when the engine is hot 80/90 deg and i'm starting the engine it runs very lean.. after a while it wil stable itself or if i push the trottle a few times it  will come back at around 14.7 AFR ealier.

Who can point me in the right direction, or suggest what figurs to change?

-More stable Idle, and the lean part on re-start a hot engine.

I made a log to identify the wrong setting?

thanks for the help.




PC Datalog - 2024-01-13 6;36;27 pm.llgx

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  • Rens changed the title to Link G4X running lean with hot start + unstable idle (subaru impreza V8)

for the lean hot startup it is due to heat soak. to combat that, you can use a 4D fuel table with IAT as X axis and engine runtime as Y axis. for higher IATs and for a given time, put something like 10% enrichment and decrease after lets say 60 second to 0 in 30 seconds.

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