14 M235i baseline to stage 2+ (dyno + Dragy testing/comparison) |
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04-01-2019, 10:23 AM | #23 | |
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04-01-2019, 05:45 PM | #24 | |
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FWIW, I had the same issue on my '14 M235i with Stage 1 HEX/VF Reflash tune.
At the time when I installed the HEX reflash, I didn't realize the factory cold-side charge pipe was a weak point. This is my daily as well, so I just wanted to flash and be done with it. About 5 months into running the reflash, I began developing the same exact high RPM hesitation you have described. Shortly after this started (~2 weeks) I had the factory cold-side charge pipe blow up and leave me on the side of the road. It's possible that my hesitation was due to a failing charge pipe connection that was leaking. It seems you have replaced your charge pipe, but maybe it's worth re-tightening all of your clamps. I know from experience on other turbo cars I have owned, that I would need to go back and re-tighten all of my T-bolt clamps after a large variance in temperature from the time of the initial install. Basically, the piping would expand and contract, leaving a lot of slack in the t-bolt clamps. Again, this may not be your issue, but might be worth it to check. I haven't had a single hesitation after replacing the factory charge-pipe with an ER charge pipe. It's been about 5 months now. One more thing: It's very easy to incorrectly install the o-rings on the charge-pipe. They can also adjust during the install process and seat poorly. Might want to confirm these as well. Quote:
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'14 M235i - VF Engineering Tune, Dinan Res Delete, Evolution Racewerks Charge Pipe '11 135i - BMS Tune, AR Downpipe Last edited by XCC Motorsports; 04-01-2019 at 05:52 PM.. |
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04-11-2019, 11:35 PM | #26 |
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04-12-2019, 12:32 AM | #27 |
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N55 Stutter
Hello All,
I'll throw in my 0.02$ on the high rpm stutter, It may a torque limitation map being reached, say the mapping only allows XXX Nm (gear dependent & rpm) The colder temps creates more torque. (The Diesel TCU has a torque limitation map, and most likely the Gasoline too) (the Diesel is limited in 1st gear) From the video it seems like a torque modulation - possibly by throttle rather than the fuel cut/redline type of torque limitation. Or the additional boost may create some type of compressor surge. or wastegate management/feedback to oontrol torque/boost /ideas off Regards,
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04-12-2019, 08:18 AM | #28 | |
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04-12-2019, 10:17 AM | #29 |
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No not at all, didn't remove anything aside from the plastice engine cover and coil packs. It was a lower profile snap-on wobble extension but otherwise it was tight, but got it out no sweat, I was surprised!
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04-12-2019, 11:26 PM | #30 | |
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It is for the auto trans, where the software has a limitation in order to protect the clutches and/or case structure. In the lower gears the internal loads are higher. That is from reading the M57 diesel forum - 6HP28 ZF auto; but logic is most likely used in other transmissions. The MT's don't have software, and haven't seen anything linked to torque limitations on MT's; though it can probably be implemented from the engine management and/or stability/traction control. So the MT's are more tuner friendly - ie rear diff ratio changes, stronger clutch, etc
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12-08-2019, 09:56 AM | #32 |
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02-05-2020, 02:05 PM | #34 |
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