MHD Stage 2+ 93 Log

jaybird98 · 09-18-2023, 02:09 PM

https://datazap.me/u/jaybird981/2011...ata=3-4-7-8-12

Trying to diagnose an issue where I have RPM's that seem to jump a bit when shifting. The log shows that the throttle is still very slightly open between shifts. Could this be why the RPM's are jumping? Maybe the clutch is slipping? I have tested this making sure my foot is completely off the accelerator and it still happens. Really throws off timing when trying to upshift quickly. This only seems to happen at RPM's above 4500ish.

Car is FBO with 116k and within the last 300 miles its had a oil change, new plugs (OEM), injectors, HPFP and HPFP sensor. Not throwing any codes and drives great besides this small issue. Any help is appreciated.

Xalithar · 09-23-2023, 09:05 PM

I would look at your Diverter valve. What you are experiencing is rev hang or rev spike. if you look at your boost it spikes at 18 or 21 psi every time you shift with boost target at 0.1. I had the same issue when i switched to a turbosmart diverter valve. I am not saying they are bad valves. mine just did'nt want to work with my car. Judging by the graph you shuld be expirancing turbo flutter.

09-18-2023, 02:09 PM	#1
jaybird98 Registered 0 Rep 1 Posts Drives: 2011 335i Join Date: Sep 2023 Location: NJ iTrader: (0) Garage List 2011 BMW 335i [0.00]	MHD Stage 2+ 93 Log - RPM Jump When Shifting https://datazap.me/u/jaybird981/2011...ata=3-4-7-8-12 Trying to diagnose an issue where I have RPM's that seem to jump a bit when shifting. The log shows that the throttle is still very slightly open between shifts. Could this be why the RPM's are jumping? Maybe the clutch is slipping? I have tested this making sure my foot is completely off the accelerator and it still happens. Really throws off timing when trying to upshift quickly. This only seems to happen at RPM's above 4500ish. Car is FBO with 116k and within the last 300 miles its had a oil change, new plugs (OEM), injectors, HPFP and HPFP sensor. Not throwing any codes and drives great besides this small issue. Any help is appreciated.
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09-23-2023, 09:05 PM	#2
Xalithar Enlisted Member 12 Rep 40 Posts Drives: BMW E90 335I X-drive (2011) Join Date: Dec 2022 Location: Norfok iTrader: (0) Garage List 2011 BMW 335i [0.00]	I would look at your Diverter valve. What you are experiencing is rev hang or rev spike. if you look at your boost it spikes at 18 or 21 psi every time you shift with boost target at 0.1. I had the same issue when i switched to a turbosmart diverter valve. I am not saying they are bad valves. mine just did'nt want to work with my car. Judging by the graph you shuld be expirancing turbo flutter.
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