[ACM335xi]

Hey guys I was wondering if anyone had any experience with a boost leak? I have a N55 335xi with JB4, BMS chargepipe, VRSF catless Downpipe, and BMW Performance Exhaust. I have my JB4 set to hijack my fuel gauge for boost when I'm over half throttle. I read the half way is 10 psi and 3 quarters is 15psi please correct me if I'm wrong, Anyways Ive noticed that when I pin it, it will bounce up to 14 psi (running map 2) then bounce down to around 4 psi and stay there or keep bouncing back and forth. I will be making a log of this tonight. I'm just wondering if anyone has had experience with this.

[ACM335xi]

So I'm dumb and had a girl moment but I was logging timing on my fuel gauge cause I had the wrong setting on my JB4, however I still found some issues while I was logging. The first concern I have is when I am under WOT my AFR's stay around 14.7 which I always thought that under WOT I should see around 12, so I'm worried that I might be running to lean when I'm under WOT. Second I'm still not seeing 14 which is what the map 2 is supposed to run. I am kind of confused on boost because I can see what its commanding but It never seems to meet it. I dont think its a boost leak because the wastegate duty cycle is sitting pretty high which doesn't make sense because if it can't make its boost why would it open the wastegate?

[tc535i]

Originally Posted by ACM335xi

So I'm dumb and had a girl moment but I was logging timing on my fuel gauge cause I had the wrong setting on my JB4, however I still found some issues while I was logging. The first concern I have is when I am under WOT my AFR's stay around 14.7 which I always thought that under WOT I should see around 12, so I'm worried that I might be running to lean when I'm under WOT. Second I'm still not seeing 14 which is what the map 2 is supposed to run. I am kind of confused on boost because I can see what its commanding but It never seems to meet it. I dont think its a boost leak because the wastegate duty cycle is sitting pretty high which doesn't make sense because if it can't make its boost why would it open the wastegate?

that isn't really lean, direct injection motors can run closer to optimal AFR where traditional fuel injection errs on the rich side just in case (closer to 12)

[ACM335xi]

Originally Posted by tc535i

that isn't really lean, direct injection motors can run closer to optimal AFR where traditional fuel injection errs on the rich side just in case (closer to 12)

oh awesome I didn't know that thank you. any ideas on my boost?