[fatlo23]

Hi, I have a 2018 340i with the B58 motor with an mhd stage 2 93 octane tune. Under low to medium load at low rpms my car will start to surge as if the throttle is opening and closing. I data logged(Can provide if needed) while it was happening and the throttle is actually opening and closing quickly causing the surging. Does anyone have any idea on what might be causing it or how to fix it?

[T_H_O_M_A_S]

i experience the same issue . but i yet have to log it when it happens ,

it feels like lots of wastegate action to me , but if you have logs to share pls do

it happens when i use comfort mode and mild to low acceleration without downshifts

[T_H_O_M_A_S]

https://datazap.me/u/thomas/throttle...ata=3-20-24-33

tried to capture it

[G.Newt]

Oscillating overboost. Your boost PSI is constantly over target, then the DME tries to correct by closing the throttle. It repeats over and over.

[Skyhigh]

@G.Newt
Caused by what...?

[kern417]

Could be poor boost control in the tune but if it just started happening then i'd check for boost/vacuum leaks, damaged wastegate actuator, etc.

[weehe126]

I have the same issue. Only happens below 2500rpms and 30-40% throttle. Pretty sure it is just poor boost control from the OTS maps. When it happens I just give it a little more/less throttle

[Skyhigh]

And MHD wouldn't know/bother, if it is a widely
spread tune issue....? 🤔

[T_H_O_M_A_S]

im waiting on a testmap from fabian to resolve the problem , on an fb page from mhd , the testtune worked well with someone who had the same problem , mhd prolly update their ots later on after some more feedback upon the problem , make sure to send them a message if you have the same problem

[T_H_O_M_A_S]

https://datazap.me/u/thomas/ots-osci...ata=3-20-24-33

this is a lot better already , surging feeling is negligible . might be between the ears aswell

[G.Newt]

Originally Posted by T_H_O_M_A_S

https://datazap.me/u/thomas/ots-osci...ata=3-20-24-33

this is a lot better already , surging feeling is negligible . might be between the ears aswell

This was a log only going up to 2,500rpm. Not sure this tell us anything. It's only targeting between 2-4psi with less than 50% pedal.
Your last log didn't show problems until 2,800 rpm lol.

[T_H_O_M_A_S]

the problems are noticable at low load in comfort ,
i dont think people drive wot all the time ,
that was already written a few posts ago

[weehe126]

So you had to get a custom tune to fix it?

[T_H_O_M_A_S]

its a testmap , i will receive more ,

then they will rollout a new ots maps after decent feedback from many clients

[T_H_O_M_A_S]

https://datazap.me/u/thomas/ots-osci...=1&data=3-4-20

update with test map 2 , three logs , low to mild boost levels

[T_H_O_M_A_S]

mhd ots maps updated

[Skyhigh]

Good job - both from you and MHD!
I am more and more attracted to trying out MHD soon.

[bartbes]

Originally Posted by T_H_O_M_A_S

mhd ots maps updated

Did the update, throttle is improved,
monitoring still crashes as soon as the dials show
both with cable or WiFi

[T_H_O_M_A_S]

i have some wifi disconnects too when im using the monitor .
it will be resolved over time

[bartbes]

MHD stated the problem is caused by using my ak motion display at the same time.

However i had everything working together before flashing.
Ill try a few things out and we’ll see

Edit: switching off the ak motion display solved the problem.

[Robs335iproblems]

I'm having this same surging issue that's no better with the updated MHD Map. I've read that there's a setting in the JB4 related to load or something else, that when changed (doubled), it eliminates the surging (I can't find the thread that I read it in). It seems that if MHD had the same customizable setting, that might solve the issue. Is there anything in the OTS tune that I can alter to replicate what the JB4 is doing?

[Skyhigh]

How about contacting MHD directly and sharing a log with them to diagnose the issue….?