[GreenF30N26]

Does anyone else experience BM3 8AT trans tune upshifting too many gears in comfort+non-sport trans mode when cruising around town? If I am driving between 25-50mph in town the trans tune will put me into a gear that runs at 1050-1200rpm. This causes the car to lug if I press the throttle gently, so I have to throttle hard to force a shift, change to sport trans mode or paddle shifters to deal with this. Right now just running manual shift mode to deal with it.

I've got a ticket open with PTF, just need time to grab some logs but wondering if I am not the only one. I expect to hear feedback that I shouldn't be driving a tuned car in comfort but my wife likes to take the car out as well and just wants to get in and go without playing around with settings.

Appreciate any feedback

[anotheran]

I returned to stock for service and car still lugs just don't hear it as much

[GreenF30N26]

I agree it lugs a little stock but it doesn't slip up that extra gear and usually remains in the 1350rpm+ range. I just hate it going down to 1050-1150rpm range.

[kobluna]

Originally Posted by GreenF30N26

I agree it lugs a little stock but it doesn't slip up that extra gear and usually remains in the 1350rpm+ range. I just hate it going down to 1050-1150rpm range.

I have with the exact same issue with BM3 tune. I have also xHP transflash and I have configured there 10% higher shift points. That helps with the RPM issue but the issue with slight acceleration remains. So if I press throttle pedal gently to gain more speed it keeps high gear in and it lugs quite heavily.

PTF modified my S1 tune so that it's stock until 2000RPM and then it gradually turn into normal S1 tune figures. This makes the transmission to shift more easily on those low RPM low throttle situations. It still lugs more than stock but is acceptable now. Of course there's now only stock amount of torque available below 2000RPM but I guess that just makes it less stressful for the engine anyway so I don't complain. Sport mode keeps RPM above that anyway so I can use it if I really need more power quickly.

I don't fully know what causes this though. Some of it is because of added low end torque but it doesn't explain all of it. I guess my tuned 320i is close to stock 328i figures but stock 328i doesn't lug that much. Even xHP didn't fully remedied the issue for me so there got to be something else PTF should alter in their tune. I just don't know what and I guess they don't know either

[GreenF30N26]

Originally Posted by kobluna

I have with the exact same issue with BM3 tune. I have also xHP transflash and I have configured there 10% higher shift points. That helps with the RPM issue but the issue with slight acceleration remains. So if I press throttle pedal gently to gain more speed it keeps high gear in and it lugs quite heavily.

PTF modified my S1 tune so that it's stock until 2000RPM and then it gradually turn into normal S1 tune figures. This makes the transmission to shift more easily on those low RPM low throttle situations. It still lugs more than stock but is acceptable now. Of course there's now only stock amount of torque available below 2000RPM but I guess that just makes it less stressful for the engine anyway so I don't complain. Sport mode keeps RPM above that anyway so I can use it if I really need more power quickly.

I don't fully know what causes this though. Some of it is because of added low end torque but it doesn't explain all of it. I guess my tuned 320i is close to stock 328i figures but stock 328i doesn't lug that much. Even xHP didn't fully remedied the issue for me so there got to be something else PTF should alter in their tune. I just don't know what and I guess they don't know either

Appreciate the feedback. Good to know that it impacts xHP as well as I was thinking that would be the solution to my problem. I guess I'll continue to work with PTF and get them to set the tune stock till 2000rpm, which is fine, but a little odd behaviour.

[benny888]

Originally Posted by GreenF30N26

Does anyone else experience BM3 8AT trans tune upshifting too many gears in comfort+non-sport trans mode when cruising around town? If I am driving between 25-50mph in town the trans tune will put me into a gear that runs at 1050-1200rpm. This causes the car to lug if I press the throttle gently, so I have to throttle hard to force a shift, change to sport trans mode or paddle shifters to deal with this. Right now just running manual shift mode to deal with it.

I've got a ticket open with PTF, just need time to grab some logs but wondering if I am not the only one. I expect to hear feedback that I shouldn't be driving a tuned car in comfort but my wife likes to take the car out as well and just wants to get in and go without playing around with settings.

Appreciate any feedback

what i found out is that when i drive at around 80km/h at highway, with bm3 8at tune, it will go lower rpm compare to stock (eco mode tested), i think this is due to bm3 tune will go upto 8th gear while stock only goes upto 7th, plus i also find that the steer wheel will vibrate when i want to put more gas to takeover at around 80km/h.

[Rockyca]

FYI... The new g20 allows the motor to lug down to below 1000RPM, around 750-800 when booting around town. I believe it is all in an effort to conserve fuel / emissions.

[GreenF30N26]

Originally Posted by benny888

what i found out is that when i drive at around 80km/h at highway, with bm3 8at tune, it will go lower rpm compare to stock (eco mode tested), i think this is due to bm3 tune will go upto 8th gear while stock only goes upto 7th, plus i also find that the steer wheel will vibrate when i want to put more gas to takeover at around 80km/h.

Yes exactly the same i get in either eco or comfort. If you try cruising @ 60km/h it will slip into 7th when it should be 6th. You are right stock doesn't allow it to slip up that extra gear to lower rpm's

[GreenF30N26]

Originally Posted by Rockyca

FYI... The new g20 allows the motor to lug down to below 1000RPM, around 750-800 when booting around town. I believe it is all in an effort to conserve fuel / emissions.

really? that's horrific. BMW, and I am sure other auto makers as well, do all kinds of weird stuff to meet dumb standards. But this really confirms that BMW really only cares that the cars last the length of the warranty. unfortunate

[VipinLJ]

Originally Posted by Rockyca

FYI... The new g20 allows the motor to lug down to below 1000RPM, around 750-800 when booting around town. I believe it is all in an effort to conserve fuel / emissions.

Really? The M340i? My G20 330i doesn't do that. Or at least, mine doesn't. Lowest I've seen it fall in eco pro with shifter in D was around 1100-1200RPMs?

[Rockyca]

Originally Posted by VipinLJ

Really? The M340i? My G20 330i doesn't do that. Or at least, mine doesn't. Lowest I've seen it fall in eco pro with shifter in D was around 1100-1200RPMs?

This was in a 2021 g20 loaner I had. I didn’t notice this in the 2020s I’ve been in.

[VipinLJ]

Originally Posted by Rockyca

This was in a 2021 g20 loaner I had. I didn’t notice this in the 2020s I’ve been in.

Ahhh. They might be re-tuned the 2021. I wouldn't ever want my car to lug. Which is why I always drive in S instead of D.

[Rockyca]

My 340 lugs a bit but not below 1000-1100 rpm and that thing has some grunt down low. My 320 doesn’t lug at all because it’s a 6spd!

[SFV818]

Has PTF fixed this issue at all yet? Should I just do a stage 2 and not do the transmission flash?

[GreenF30N26]

Originally Posted by SFV818

Has PTF fixed this issue at all yet? Should I just do a stage 2 and not do the transmission flash?

There is no formal fix. You can open a case with PTF and they will ask for a log from 3-5 gear WOT and they will make changes to your tunes to help.

[atpenney]

Originally Posted by GreenF30N26

There is no formal fix. You can open a case with PTF and they will ask for a log from 3-5 gear WOT and they will make changes to your tunes to help.

I have this same issue with lugging at low speeds. Not sure why the tune wants to be in 7th gear at 50km/h. Makes me want to flash back to stock for city driving. I thought my spark plugs were toast but they were perfectly fine so I guess the tune is to blame.

[GreenF30N26]

Originally Posted by atpenney

I have this same issue with lugging at low speeds. Not sure why the tune wants to be in 7th gear at 50km/h. Makes me want to flash back to stock for city driving. I thought my spark plugs were toast but they were perfectly fine so I guess the tune is to blame.

I think if everyone impacted opens a case with PTF we could get some momentum for them to change the tune. Agreed it doesn't make sense to have the gears up-shift the way they do on comfort.

[SFV818]

Originally Posted by GreenF30N26

I think if everyone impacted opens a case with PTF we could get some momentum for them to change the tune. Agreed it doesn't make sense to have the gears up-shift the way they do on comfort.

So for someone who hasn't flashed BM3 yet (me)... it sounds like i should avoid flashing the transmission for now. I will stick with just a stage 2 flash. I am often at slow city speeds so I do not want to run into this lug issue people are talking about.

[atpenney]

Originally Posted by GreenF30N26

I think if everyone impacted opens a case with PTF we could get some momentum for them to change the tune. Agreed it doesn't make sense to have the gears up-shift the way they do on comfort.

I opened a support ticket with ptf and Dzenan asked for a datalog. When I asked him what gear or speed he wanted the log at he sent me the how to datalog link. Not sure how a 3rd gear pull starting at 2500rpm would point out our issue...Nevertheless I'll do the datalog anyway just in case he's able to revise the tune

[GreenF30N26]

Originally Posted by atpenney

I opened a support ticket with ptf and Dzenan asked for a datalog. When I asked him what gear or speed he wanted the log at he sent me the how to datalog link. Not sure how a 3rd gear pull starting at 2500rpm would point out our issue...Nevertheless I'll do the datalog anyway just in case he's able to revise the tune

ya they asked me for a datalog from 3rd to 5th WOT which I didn't understand also why they would need that to determine the transmission tune is upshifting too many gears are cruising speed. Also, don't want to lose my car if I get caught going WOT into 5th gear.

let us know how it goes

[GreenF30N26]

Originally Posted by SFV818

So for someone who hasn't flashed BM3 yet (me)... it sounds like i should avoid flashing the transmission for now. I will stick with just a stage 2 flash. I am often at slow city speeds so I do not want to run into this lug issue people are talking about.

Couple lines of thought here.
1) The trans tune helps support the stage 2 tune with better clamping during shifts. This should benefit the longevity of the transmission with the stage 2 tune. No alternative to this if you don't use the trans tune, but many people have run the stage 2 tune without the trans tune so it may not be necessary.

2) Trans tune causes upshift while cruising in city in comfort mode which leads to lugging. Obviously not good, but you can avoid this by changing comfort to sport or sport+ mode or moving trans shifter into sport. Allows you to keep the trans tune but you will lose some gas mileage since you can run comfort mode in city.

3) Tune both then take logs and work with PTF to see if they can fix the trans tune shifting. Likely the best option since you should datalog and get them to review after you flash stage 2 to ensure everything is clean.

[SFV818]

Originally Posted by GreenF30N26

Couple lines of thought here.
1) The trans tune helps support the stage 2 tune with better clamping during shifts. This should benefit the longevity of the transmission with the stage 2 tune. No alternative to this if you don't use the trans tune, but many people have run the stage 2 tune without the trans tune so it may not be necessary.

2) Trans tune causes upshift while cruising in city in comfort mode which leads to lugging. Obviously not good, but you can avoid this by changing comfort to sport or sport+ mode or moving trans shifter into sport. Allows you to keep the trans tune but you will lose some gas mileage since you can run comfort mode in city.

3) Tune both then take logs and work with PTF to see if they can fix the trans tune shifting. Likely the best option since you should datalog and get them to review after you flash stage 2 to ensure everything is clean.

Sorry if this is a dumb question, but what do you mean by "better clamping during shifts"?