11-14-2020, 11:47 AM | #1 |
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2020 M340 broke my driveshaft
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11-14-2020, 01:03 PM | #2 |
めらみぽっぷ fan
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Ouch... Hope that new part works!
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2020 330i xDrive in mineral white.
Username and profile picture in admiration of the goddess of treble, めらみぽっぷ (Meramipop). https://www.youtube.com/watch?v=fQYWhQXOeQg https://open.spotify.com/playlist/1w...1L3y6cmPEyGSoI |
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11-14-2020, 01:17 PM | #3 |
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11-14-2020, 02:30 PM | #4 |
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sh*t sorry to see that - saw your comments in the M340 Gang group chat
watched your clip start to finish - very informative thanks for the share! Looking forward to hearing what you have to say about that new part when it comes in. |
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11-14-2020, 02:42 PM | #5 |
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Thank you 🙏🏼 and it happens happy it's just something simple
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11-14-2020, 02:57 PM | #7 |
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11-15-2020, 10:52 AM | #11 |
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Glad to hear your transmission is ok. Every platform has its weaknesses. Coming from a VR30 platform I went through so many injectors and other issues lol.
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11-02-2023, 01:31 PM | #12 |
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Hey I know this has been a while.
But do you know what symptoms you faced? I think I may have the same issue but can’t tell. No CEL or codes. But from 1st to 2nd shift, there is a super loud thud and it’s very violent. All gear shifts after are less and less violent as they go on. I’m having a lot of other symptoms as well. Any help would be appreciated. Thank you! |
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11-03-2023, 09:59 AM | #13 | |
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If your tune is downscaling the torque values sent to the tcu, so the tcu thinks its getting less torque than it is - then likely that is causing issues. The TCU stock, will send a request to the DME to reduce torque when it gets anything over 550nm. Less in gears 3 and 6. Your tune can either ignore that request - which is OK, or it can trick the tcu and downscale the values sent to the tcu - which is bad. Alternatively, it could do as instructed and reduce torque - also ok. If your tuned DME listens to the tcu and reduces torque when requested, then you'd need XHP to remove the torque limits. My first tune downscaled and I had shudders at a gear change. I immediately figured out what was happening and ditched the tune. I also now run XHP with a different tune. My shifts are fine now. Hope this helps. Last edited by cyam; 11-03-2023 at 10:04 AM.. |
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11-06-2023, 10:41 AM | #14 | |
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I use xhp. All settings are stock. I’ve run stage 0-3 with several changes in settings. But still depending on who much throttle I give it, the shifts tend to do a quick shudder. The only correlation I could find at all for this was log for the torque act. Clutch. When I logged that, I saw that any time there was a hard heat shift (or anything in smooth on the shift), the values for the torque act. clutch would dip down a bit. But when the shifts were nice and smooth. That same value would remain relatively the same. |
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11-06-2023, 11:02 AM | #15 |
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Drives: BMW M340i
Join Date: Sep 2019
Location: South FLA
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Of course this happened in NY!!!
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11-06-2023, 07:17 PM | #16 | |
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Two ways I could see my first tune was downscaling. First from the torque gauge in the sports gauges. It would hit 500nm and never go above it, even though I knew I was getting over 600nm (The scale went up to 700nm). That gauge shows the exact same values the DME is sending the TCU. I tested this with the XHP torque limits - I set that to 300nm and the gauge only went to 300nm, tried it at 400nm - same. So it does show exactly what the TCU sees. Secondly with XHP I used the line pressure bump feature which increase line pressures by about 15% - the problem went away. So it was clear. The TCU thought it was getting 500nm when it was getting much more, so the line pressures were too low - thus the occasional slipping and shuddering under WOT. Then switching to MHD - no issues since at all (without using the line pressure bump). If you are certain your tune is not downscaling torque values, then contact XHP and speak with them I have found them very helpful and responsive. |
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11-06-2023, 08:43 PM | #17 |
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Man that is a lot of info!
Thank you so much for the in depth response. I’ll have to do a lot more research and testing on my own to figure out what exactly is going on. I’m on stage 2 MHD and stage 3 xhp but don’t know how it affects my car exactly |
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11-06-2023, 11:27 PM | #18 | |
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I'd speak to XHP and explain your issues. I found them very responsive and helpful. Might be a good idea to try XHP Stage 1 - that's essentially stock. Stage 2 and 3 can become a bit "harsh". Some gearbox specialists have said stage 2 and 3 will cause premature wear. XHP say it definitely won't. I believe Stage 2 and 3 change how the torque converter works - possibly allowing less slip making the transfer of power more "direct". This has obvious benefits, but maybe in your case it is causing an issue. But Stage 1 is certainly "softer" on the gearchanges in general. See if that reduces your issues. I don't really know enough to be able to help. I am only going by my experiences and what I have learned. But XHP know their product inside out and may be able to shed more light. You could also speak to MHD - I have found them also helpful and responsive when I have asked them questions. Last edited by cyam; 11-06-2023 at 11:39 PM.. |
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