3rd & 6th gear torque limits on the 8HP45 - Elephant in the room?

badbread · 04-24-2018, 10:47 AM

Wish I could be of more assistance with this, you guys are unfortunately way above my knowledge level. Thanks for all this info everyone, some great stuff here. I hope XHP is watching!!

cookiesowns · 04-24-2018, 03:38 PM

Quote:

Originally Posted by bradsm87

I spent another few hours decompressing and checking more files from random cars like F07, F15 etc and the solid pattern is that every ROM that has the higher torque limits also has the different system pressure EDS scaling which would cause lower system pressure than it should with our F30, F10 mechatronics.

Have you looked at the EU / Asia TCU flashes of a few 535i F07 and F30's? PWG, so 2010-2013 era cars.

There's a user reporting that there cars on stock flashes run with no limits on the MHD OTS tune.

I haven't had time to narrow this down.

bradsm87 · 04-24-2018, 03:50 PM

Quote:

Originally Posted by cookiesowns

Quote:

Originally Posted by bradsm87

I spent another few hours decompressing and checking more files from random cars like F07, F15 etc and the solid pattern is that every ROM that has the higher torque limits also has the different system pressure EDS scaling which would cause lower system pressure than it should with our F30, F10 mechatronics.

Have you looked at the EU / Asia TCU flashes of a few 535i F07 and F30's? PWG, so 2010-2013 era cars.

There's a user reporting that there cars on stock flashes run with no limits on the MHD OTS tune.

I haven't had time to narrow this down.

Yes I looked at those ones too. The ones with the higher torque limits also have the different system pressure valve. I think the other mechatronics type made it into some random cars due to availability at the time.

valve float · 04-30-2018, 04:01 PM

my most recent 6th gear WOT 3-4k pull...

i should be boosting twice that...

https://datazap.me/u/valvefloat/log-...&data=3-4-5-14

3rd tops out at 12psi/13 requested...with soft boost curve

https://datazap.me/u/valvefloat/log-...=0&data=3-4-14

bradsm87 · 04-30-2018, 07:50 PM

There are several options at the moment (ordered best to most compromised):

1) Wait for an aftermarket TCU flash.

2) Swap in mechatronics from an N55B30O0 model's transmission and run the closest OEM calibration to your model.

3) Make the DME ignore the TCU's torque limiting requests.

4) Run a calibration from an N55B30O0 model without swapping mechatronics (system pressure will be lower).

5) Under-report torque to get it under the 440nm 3rd gear limit and just deal with the lower output in 6th.

I'm not looking to push the midrange as much as the OTS maps so I'm going for option 5 then option 1 eventually.

Lancelot · 08-13-2018, 10:43 AM

Picking up this interesting thread, I just realized that my AH3 is also limited in 6th gear, I was looking for the reason why I had throttle closure in 6th gear, turns out I'm pretty sure I was exceeding a threshold which I believe is set at 450Nm.

No problem pushing 600Nm in other gears as far as I can see.

afranke · 08-13-2018, 11:42 AM

Quote:

Originally Posted by Lancelot

Picking up this interesting thread, I just realized that my AH3 is also limited in 6th gear, I was looking for the reason why I had throttle closure in 6th gear, turns out I'm pretty sure I was exceeding a threshold which I believe is set at 450Nm.

No problem pushing 600Nm in other gears as far as I can see.

I still think my posts/research about the issue are extremely relevant despite being seemingly looked over:

Quote:

Originally Posted by afranke

IIRC it has something to do with which clutches are engaged, but I can't find that source at the moment. Even the GA8P70H (aka 8HP70) on the AH3 with the higher torque limits still has a limiter in at least 6th. Even on a stock tune, I know exactly when I shifted into six just from the damn clunk I feel. Here's some tech specs for fun: https://www.motor.com/newsletters/20...8HP_Tranny.pdf

Quote:

Originally Posted by afranke

I think I figured something out. It's because when clutches C and E are engaged, they both engage on the same part inside the transmission at the same time, likely putting more force on that part. You'll notice in the link in my last post that C&E are both engaged only on 3rd and 6th. Check out this video to see the part they both engage on, seems like a weak link: https://youtu.be/FqyPizRyphQ?t=913

Lancelot · 08-13-2018, 11:45 AM

I did see them indeed, and only today made the link btw my tune issues and this.

If/when i have a moment i'll try to reverse engineer the coding files to see which limit we have for the AH3.

Eschmacher · 08-17-2018, 12:54 PM

Just thought I'd mention in here, it sounds like xHP will be adding support for the ZF8 gearboxes in the near future ("this autumn"). Hopefully this will provide a workaround for these torque limits?

I can feel the difference in 3rd/6th and I'm only stage 1. Really hoping we can get around this soon.

bqik · 08-17-2018, 02:48 PM

I have the MPPK software and it is obvious in 3rd but more in 6th so I can't imagine in softwares with higher Torque in other gears...

G-Power has software for it AFAIK.

regards

Bimmertodd88 · 08-17-2018, 03:28 PM

Quote:

Originally Posted by Eschmacher

Just thought I'd mention in here, it sounds like xHP will be adding support for the ZF8 gearboxes in the near future ("this autumn"). Hopefully this will provide a workaround for these torque limits?

I can feel the difference in 3rd/6th and I'm only stage 1. Really hoping we can get around this soon.

Stage 1 on what?

Eschmacher · 08-18-2018, 10:09 AM

Quote:

Originally Posted by Bimmertodd88

Stage 1 on what?

BM3.

Bimmertodd88 · 08-18-2018, 10:41 AM

Quote:

Originally Posted by Eschmacher

Quote:

Originally Posted by Bimmertodd88

Stage 1 on what?

BM3.

Oh yeah. It's like hitting a brick wall in 6th gear

Eschmacher · 08-18-2018, 04:43 PM

Quote:

Originally Posted by Bimmertodd88

Oh yeah. It's like hitting a brick wall in 6th gear

Yep, that's exactly what I'm feeling. 3rd isn't great either, feels ok WOT, then I shift to 4th and it it feels like it takes off.

Bimmertodd88 · 08-19-2018, 05:43 PM

Quote:

Originally Posted by Eschmacher

Quote:

Originally Posted by Bimmertodd88

Oh yeah. It's like hitting a brick wall in 6th gear

Yep, that's exactly what I'm feeling. 3rd isn't great either, feels ok WOT, then I shift to 4th and it it feels like it takes off.

Yup exactly. Can't wait to get it removed

bradsm87 · 08-19-2018, 06:03 PM

Wow I thought BM3 had implemented a good workaround for this. So both MHD and BM3 users are experiencing torque limits in 3rd and 6th?

Bimmertodd88 · 08-19-2018, 08:47 PM

Quote:

Originally Posted by bradsm87

Wow I thought BM3 had implemented a good workaround for this. So both MHD and BM3 users are experiencing torque limits in 3rd and 6th?

Indeed. I have bm3 and have heard nothing back from them since I opened a ticket. MHD told me they will have a update soon.

XxThe_RemedyXx · 09-03-2018, 05:30 PM

Quote:

Originally Posted by Bimmertodd88

Quote:

Originally Posted by bradsm87

Wow I thought BM3 had implemented a good workaround for this. So both MHD and BM3 users are experiencing torque limits in 3rd and 6th?

Indeed. I have bm3 and have heard nothing back from them since I opened a ticket. MHD told me they will have a update soon.

Any word on this?

Bimmertodd88 · 09-03-2018, 05:32 PM

Quote:

Originally Posted by XxThe_RemedyXx

Quote:

Originally Posted by Bimmertodd88

Quote:

Originally Posted by bradsm87

Wow I thought BM3 had implemented a good workaround for this. So both MHD and BM3 users are experiencing torque limits in 3rd and 6th?

Indeed. I have bm3 and have heard nothing back from them since I opened a ticket. MHD told me they will have a update soon.

Any word on this?

Nope......

Jpup · 09-03-2018, 10:37 PM

If xHP adds support, that would be our best bet

bradsm87 · 09-03-2018, 11:39 PM

Quote:

Originally Posted by Jpup

If xHP adds support, that would be our best bet

I wish they'd just release the flasher and worry about OTS maps later. The torque limits are easy to change.

cxp213 · 09-04-2018, 03:58 PM

MHD's been lagging on this for months. It was originally brought up off the forums in their beta chat months ago and they shortly had a "fix" for it which got sent to some members, but we never really heard much about it since. Despite a remedy being available and some people even having tested it, our N55 OTS maps were never updated (haven't been in months, actually) and all they ever posted was the fix was going to be implemented "in a few weeks." I'll refrain from posting my opinions on this matter, but this is just laughable.

04-24-2018, 10:47 AM	#45
badbread not good, but bad 333 Rep 361 Posts Drives: 2013 335i Join Date: Jun 2016 Location: Bay Area, CA iTrader: (3)	Wish I could be of more assistance with this, you guys are unfortunately way above my knowledge level. Thanks for all this info everyone, some great stuff here. I hope XHP is watching!! __________________ They are spelled BRAKES not breaks!!!! Oh FFS, not another spark plug thread! BreadsBMW on Youtube Last edited by badbread; 04-24-2018 at 10:47 AM.. Reason: i cant spellz
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04-30-2018, 04:01 PM	#48
valve float Private First Class 163 Rep 136 Posts Drives: b6 a4 avant 6sp, e90 M3 6sp Join Date: Sep 2017 Location: BC - Canada iTrader: (0)	my most recent 6th gear WOT 3-4k pull... i should be boosting twice that... https://datazap.me/u/valvefloat/log-...&data=3-4-5-14 3rd tops out at 12psi/13 requested...with soft boost curve https://datazap.me/u/valvefloat/log-...=0&data=3-4-14
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04-30-2018, 07:50 PM	#49
bradsm87 Lieutenant Colonel 595 Rep 1,693 Posts Drives: F25 LCI xDrive30d Join Date: Jun 2013 Location: Australia iTrader: (0)	There are several options at the moment (ordered best to most compromised): 1) Wait for an aftermarket TCU flash. 2) Swap in mechatronics from an N55B30O0 model's transmission and run the closest OEM calibration to your model. 3) Make the DME ignore the TCU's torque limiting requests. 4) Run a calibration from an N55B30O0 model without swapping mechatronics (system pressure will be lower). 5) Under-report torque to get it under the 440nm 3rd gear limit and just deal with the lower output in 6th. I'm not looking to push the midrange as much as the OTS maps so I'm going for option 5 then option 1 eventually.
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08-13-2018, 10:43 AM	#50
Lancelot Major 568 Rep 1,290 Posts Drives: 2017 m550i Join Date: Sep 2012 Location: France iTrader: (0)	Picking up this interesting thread, I just realized that my AH3 is also limited in 6th gear, I was looking for the reason why I had throttle closure in 6th gear, turns out I'm pretty sure I was exceeding a threshold which I believe is set at 450Nm. No problem pushing 600Nm in other gears as far as I can see. __________________ 2017 M550i \| Sophistograu Previous cars: 2014 F30 ActiveHybrid 3 \| 2012 f20 M135i
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08-13-2018, 11:45 AM	#52
Lancelot Major 568 Rep 1,290 Posts Drives: 2017 m550i Join Date: Sep 2012 Location: France iTrader: (0)	I did see them indeed, and only today made the link btw my tune issues and this. If/when i have a moment i'll try to reverse engineer the coding files to see which limit we have for the AH3. __________________ 2017 M550i \| Sophistograu Previous cars: 2014 F30 ActiveHybrid 3 \| 2012 f20 M135i
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08-17-2018, 12:54 PM	#53
Eschmacher Car Hypochondriac 335 Rep 901 Posts Drives: 2014 335i M-Sport Estoril Blue Join Date: Feb 2017 Location: Sterling, VA iTrader: (0) Garage List 2014 BMW 335i [0.00]	Just thought I'd mention in here, it sounds like xHP will be adding support for the ZF8 gearboxes in the near future ("this autumn"). Hopefully this will provide a workaround for these torque limits? I can feel the difference in 3rd/6th and I'm only stage 1. Really hoping we can get around this soon.
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08-17-2018, 02:48 PM	#54
bqik Private First Class 78 Rep 109 Posts Drives: 435i Join Date: Feb 2018 Location: Andorra iTrader: (0)	I have the MPPK software and it is obvious in 3rd but more in 6th so I can't imagine in softwares with higher Torque in other gears... G-Power has software for it AFAIK. regards
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08-19-2018, 06:03 PM	#60
bradsm87 Lieutenant Colonel 595 Rep 1,693 Posts Drives: F25 LCI xDrive30d Join Date: Jun 2013 Location: Australia iTrader: (0)	Wow I thought BM3 had implemented a good workaround for this. So both MHD and BM3 users are experiencing torque limits in 3rd and 6th?
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09-03-2018, 10:37 PM	#64
Jpup Private 26 Rep 63 Posts Drives: 2015 435i Join Date: Apr 2018 Location: Ventura, CA iTrader: (0)	If xHP adds support, that would be our best bet __________________ 2015 435i (current): VRSF Catless Downpipe, Bootmod3 Stage 1, xHP 2008 Corvette (sold):Vortech supercharger, ported/built heads, catless 2015 M235i (sold): CTS Turbo Intake, VRSF Catless Downpipe, CSF FMIC, MPE, xHP, Bootmod3 Stage 2 E30
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09-04-2018, 03:58 PM	#66
cxp213 Lieutenant 313 Rep 525 Posts Drives: M235i Join Date: Apr 2017 Location: TX iTrader: (0)	MHD's been lagging on this for months. It was originally brought up off the forums in their beta chat months ago and they shortly had a "fix" for it which got sent to some members, but we never really heard much about it since. Despite a remedy being available and some people even having tested it, our N55 OTS maps were never updated (haven't been in months, actually) and all they ever posted was the fix was going to be implemented "in a few weeks." I'll refrain from posting my opinions on this matter, but this is just laughable.
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