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Stage1+SF 91 Octane what could be causing uneven aceloration/boost issues

959 Views 3 Replies 3 Participants Last post by  Cherylynn
So I dont know exactly how best to explain this but maybe someone else has/had the same problem w/ this map or can at least understand the general concept i'm trying to get out- Keep in mind I havnt had the chance to log any data & upload it to see what may be problem, thats on the agenda tonight- but whats happening is in usually 3rd gear as I speed up (not going all out) it feels like the the car is hesitating slightly as if I were letting off the accelorator just a tiny bit and then getting back on the accelorator a tiny bit & it does this jerky thing unless I'm on it hard/WOT. I was thinking it may be an AFR issue or maybe its the adjustment of my hybrid BOV- Any ideas or suggestions??
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Its probably related to how much your throttle is opening. If you are not WOT, it may be doing wacky stuff. Your car may also be pulling timing to conserve fuel and maintain stoich. Get some logs or all we can do is guess.
Cherylynn, I was seeing the exact same thing in 3rd with the 93 Octane version of the map you're running. This weekend I switched to the 91 Octane version and it's smoother but my LTFT's are the best.
I have figured it out! Part throttle OVER boost causes the jerkiness. Which basically means suddenly the turbo can spool way too much with very little rpm or throttle opening. This becomes a problem as now your turbo is trying to force too much air thru the throttle body but because the throttle body is only partially open, the air has nowhere to go and forces it's way back thru the turbo, causing compressor surge, and the characteristic fluttering IE jerkiness. This is torture on your turbo apparently- A lot of people also suggest that the motor will run way too lean during part throttle overboost...
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