Sluggish throttle response - choking/gurgling

[Froglet]

I have an E90 M3 DCT and I noticed that sometimes the throttle response is pretty sluggish. I get this, maybe obviously in D2, but I also noticed that sometimes when driving with D4/D5 it's still pretty slow. In D4/5 I would expect it to respond pretty quickly to when I slightly touch the accelerator and it does appear to want to do something, but it seems to choke/gurgle and if I press the accelerator a bit more it all of a sudden takes off like crazy which could be pretty dangerous in some situations.

I have read about throttle actuators but I don't seem to have any other symptoms (like car stalling when stopping for a traffic light, having irregular rpms at cold start or getting error codes - I read those are some symptoms...). When I drive using the paddles/stick and accelerate in any gear it responds very well to whatever I do with the accelerator... Any ideas?

Could it be the rod bearings?........ Just kidding

[Helmsman]

Power button engaged yeah..?

[LIMITLESS_M3]

Originally Posted by Froglet

I have an E90 M3 DCT and I noticed that sometimes the throttle response is pretty sluggish. I get this, maybe obviously in D2, but I also noticed that sometimes when driving with D4/D5 it's still pretty slow. In D4/5 I would expect it to respond pretty quickly to when I slightly touch the accelerator and it does appear to want to do something, but it seems to choke/gurgle and if I press the accelerator a bit more it all of a sudden takes off like crazy which could be pretty dangerous in some situations.

I have read about throttle actuators but I don't seem to have any other symptoms (like car stalling when stopping for a traffic light, having irregular rpms at cold start or getting error codes - I read those are some symptoms...). When I drive using the paddles/stick and accelerate in any gear it responds very well to whatever I do with the accelerator... Any ideas?

Could it be the rod bearings?........ Just kidding

I have observed the same. The power delivery can be quite inconsistent.
I have my own theory. If you drive the car above 60 mph for 45 min it will respond much more favorably after that. Unfortunately the DME continuously adapts the engine map correction factors to your driving style and shoots for minimum emissions, and preserving engine wear, not performance (even with power plus mode which only scales the throttle). Unless you floor it that mid level performance is ellusive.
If you do normal driving like you would in most road driving, the DME tries to protect the engine by running rich and giving you shitty performance at in moderate engagements. Highway driving will make it run more lean and bring back more performance in transitional driving.
So the only solution I found is to make some weekend trips. Unfortunately the effect dissipates after a few days.

note that this layer of control is lower lever and no remap or tune will stop the DME from doing that. I hate those software adaptation that are taking control away from the human driver. Same thing creeped in dct.

[Froglet]

But if it were normal, I guess more people would have been complaining about it though...

[Helmsman]

Hi Froglet, indeed there has been quite a lot if discussions on this DME "adaption" if you search. It does makes sense, but for instance in my case I've never noticed it.

[LIMITLESS_M3]

Originally Posted by Helmsman

Hi Froglet, indeed there has been quite a lot if discussions on this DME "adaption" if you search. It does makes sense, but for instance in my case I've never noticed it.

the e46 had it, the e39 had it, and there is no question the e92 has it, it's only getting more and more pervasive with more embeded computing power in cars.
At least in the e46 there was a known way to "reset" back those adaptive correction factors to factory settings but a.f.a.i.k in the e92 m3 you have to have some bmw oem writting tools equipment, and even then it's never turned off, so you have to regularly reset it.

Plenty of people won't complain, they'll assume it's a mechanical limitation of the engine, it's not ! Also because it doesn't affect the top end (full throttle) when you floor it, but anything less on the throttle and the DME will hold back and overprotect the engine and act like a stinky banker not letting you withdraw money from your own account unless you shout at him.

Why do you think some people have complained the s65 is lacking torque ? The dyno curve (at full throttle) is in contradiction with that statement, but dynos are taken at full throttle a situation in which the DME is clearly being told to STFU and not mess up power delivery. But in daily driving when people are expecting a brisk take off at mid-level throttle, the DME is in full action and interferes and makes the engine responds like a slug they'll assume the s65 is torque less. It really is a DME adaptation interfering issue.

I think keen drivers that have a knack for knowing their engines in every driving situation and corners are the ones who will have noticed it. Average M3 drivers (the majority) will just lament how the s65 is undertorqued (wrong conclusion). Unfortunately the DME hard coded software is an integral part of an engine development and one that is not writable, just like a computer operating system. Only BMW could upgrade it, but they have zero incentive to do so. No level of tuning can over write those low level of code.

Personally i have observed unmistakenly, like i said that if you go on a long trip, in the following days the engine will be more 'eager' in those mid-level acceleration (no hesitation, no gargling). I don't know why but it seems to neutralize the adaptation for a few days and then it's back to normal.

Maybe it would be best described with an animal comparison. With the DME adapting the car feels like an aged lion, lethargic at lower speeds it does not use its power unless the chance/reward factor is high, only then does it go crazy fast.
Without DME adaptation interfering the car is like a mangoose a low speed, fast to react and nervous and a cheetah at fast speed.