N54 Advanced Throttle Response Mystery

[KClemente]

Long story short, my brother and I just did a whole overhaul on his E61 N54 which involved a manual swap and upgraded hybrids. I haven't flashed my custom tune for him yet but I did notice that his throttle response (Response time between accel pedal setpoint and throttle setpoint) was near instantaneous on his wagon versus my own car.

I'd already performed a complete manual swap which involved resetting "variant adaption" on the DME. His torque request tables on his current tune are actually a tiny bit less aggressive than mine

Driving his wagon feels like my dad's E90 M3, and if anyone's ever driven an S65, the throttle response is absolutely amazing

I've attached a couple screenshots of my car and my brothers wagon, I can also upload the logs if needed. You can see on the delayed throttle picture that the throttle body actually waits before operating

If we as a collective can figure out the gradient limitations and response times of the throttle body, it will completely change how our cars drive and react to pedal changes. @carabuser @jyamona @chrisdfv @AzNdevil @RSL @anyone

Last note: I am on JB4 currently which may or may not change the responsiveness as it has it's own built in rudimentary throttle mapping. Also both cars already have the throttle correction changes applied. If someone on flash only can take a log of cruising going from 0-50% throttle (with throttle correction applied), I'd greatly appreciate it. I can provide our torque request maps if needed.

 

[KClemente]

Here's a screenshot of PeterY's throttle sensitivity thread which highlights the differences between a stock IJ and a stock IK DME.

 

[JohnDaviz]

I got curious about your information so I checked my logs. I zeroed all cells in the throttle response maps in those maps also with the existing XDF files.

I compared an IJE0S and INA0S map with stock map sensor and one INA0S map with N20 sensor just for your reference.

Delay in IJE0S nearly 0 bot at command of opening the throttle plate and 100% request

INA0S stock MAP sensor with a delay in reaction of 0.1s

INA0S N20 Sensor with a delay of 0.3s of opening the throttle plate but at 100% open command there is no delay visible

You can clearly see the initial delay of opening request but faster opening of the plate compared to the other logs.

 

[KClemente]

@JohnDaviz thanks for being very informative. All three of those tests are super interesting in how the throttle plate reacts differently.

Now it may not seem like much, but that 0.3 of a second is actually a really long delay when you take in the fact that the average human reaction time is about 150-300 milliseconds.

The faster plate speed on the IN N20 car is also interesting because there are maps and calibrations to actually slow the plate down and prevent the throttle body from actually actuating that fast, which explains the first two photos

Attached are some of the calibrations I am going to test out tomorrow, the gradient limitation having a Min/Max of 0° and 119.5°. Also attached is a diagram briefly showing how these limitations are implemented.

c_tps_sp_tol has a stock limitation of 78° and c_tps_sp_bol has a stock limitation of 4°

lgrd_stop/tot is also clearly visible on each log you and I attached

And if anyone else has any ideas, feel free to jump in and I'll do my best to try them out. I'll do my best to define any map for anyone to try out

 

[carabuser]

I'll have a look and see if anything obvious shows up.

Your brothers car is just stock IJE0S?

There is some logic dedicated to anti-jerk in the DME and also load shock damping. I've turned it off in the past while playing around and it certainly made things feel different but in a bad way. Made shifts really abusive. The values vary greatly between different transmission options.

If you wanted to try them out on INA0S I have exported them and attached them here. The options are in the description of each.

 

[carabuser]

From reading through the documentation it looks like the pedal value filtering tables that have already been defined are the ones you are after.

There are some gradient tables, C_TPS_SP_LGRD_STOP and C_TPS_SP_LGRD_TOT that could be increased to allow a faster moving throttle but I don't think they are causing the delay you are chasing. It could be coming from the BMW layer where the throttle setpoint originates, the pedal value is filtered by the tables already mentioned and that is passed to the BMW layer where it's used to generate a torque request, that then ends up as a target airmass flow which is is used to generate a requested throttle angle which is then passed back to the Continental layer where it uses the tables I mentioned above to filter the value before the request is sent to the throttle.

There's separate tables for each MT, AT and DCT in the throttle correction XDF. Are you sure you have them zeroed out for your correct trans? I would just set them all the same just in case.

Also the JB4 won't be helping, I'd bin that first before changing anything else.

 

[KClemente]

@carabuser His IJ currently has a custom tune I made for him for his stock turbos. He no longer has stock turbos but before I want to reflash it for his hybrids, he mentioned how insanely fast his throttle response is, even at very little pedal input. Due to special circumstances ie: manual swap, I can't replicate it on my car, but it happened right after I reset the variant adaptation in INPA.

I'm interested in the anti-jerk feature in the DME and never found it until you sent over that xdf. I've always disabled them in MS43's and even MSS60's with success.

I'll try porting that xdf over to I8 and get to testing them immediately with my manual trans.

 

[KClemente]

Also what's interesting that I just realized is that, his car also has a near instantaneous fuel cut. I set his timer to 1.6 seconds in his bin, and in the log with his throttle response, its more like 100-200 milliseconds.

You can definitely feel the car jerk when you press the throttle, and feel the car lean forward when you release the throttle. Kind of like an old bike or a drive by cable car.

 

[KClemente]

Okay @carabuser I think you nailed it right on the head.

Porting the dashpot and LSD configuration over was simple as the bits lined up and was easy to spot. Zeroed both configs out and took it for a test drive and knew it was it immediately. My car now responds immediately to any throttle input and instantly closes the throttle blade as soon as the accel pedal is lifted.

I could see how DCT and Auto cars will not respond nicely to this. My car does buck forward upon lifting the throttle pedal as torque is instantly removed.

Attached is a quick test down my street. I'll do a more extensive test in a bit.

I'm now looking at any calibration that ends in _AR which has the nice nomenclature of Antiruckel, or Anti Jerk.

Note: because of the polling rate of the JB4, it shows that the pedal and throttle have a little delay in it, but I assure that there is absolutely zero delay. I'll test it out on cars with flash only soon

 

[carabuser]

Also what's interesting that I just realized is that, his car also has a near instantaneous fuel cut. I set his timer to 1.6 seconds in his bin, and in the log with his throttle response, its more like 100-200 milliseconds.

You can definitely feel the car jerk when you press the throttle, and feel the car lean forward when you release the throttle. Kind of like an old bike or a drive by cable car.

There's a few different fuel cut timers depending on conditions. The main two when driving are ip_t_min_pu_n_tco in Normal mode and ip_t_min_pu_rng_l__n__tco in Sport.

 

[carabuser]

Okay @carabuser I think you nailed it right on the head.

Porting the dashpot and LSD configuration over was simple as the bits lined up and was easy to spot. Zeroed both configs out and took it for a test drive and knew it was it immediately. My car now responds immediately to any throttle input and instantly closes the throttle blade as soon as the accel pedal is lifted.

I could see how DCT and Auto cars will not respond nicely to this. My car does buck forward upon lifting the throttle pedal as torque is instantly removed.

Attached is a quick test down my street. I'll do a more extensive test in a bit.

I'm now looking at any calibration that ends in _AR which has the nice nomenclature of Antiruckel, or Anti Jerk.

Note: because of the polling rate of the JB4, it shows that the pedal and throttle have a little delay in it, but I assure that there is absolutely zero delay. I'll test it out on cars with flash only soon

If that's the case then the delay in logs is just a result of the torque management routine adding the damping factor to the torque request.

There's a lot more toggles and tables relating to those LSD, Dashpot and AJ functions but I only ever just tested disabling them. It does feel very raw and instant but I quite like a bit of smoothing from the DME. My thought was that having it instant like that would just cause undue wear and tear on the drivetrain and bushings. It did make the DCT shifts even more ridiculous when in drivelogic mode 6, just like a proper sequential box.

 

[RSL]

Maybe someday I'll get notified of the tag.

Torque controls are probably the actual driver and TPS is a side effect. PV/correction tables work somewhat because they modify the input side, which effects everything after, but will still be limited by output controls.

For MT swap, might just be clutch switch or some status bit value missing or lack of any TCU controls altogether now. I doubt there is any radical difference in IJ's that would account for it, the major change was taking the TCU and the more cumbersome AT itself out of the loop.

 

[KClemente]

Maybe someday I'll get notified of the tag.

Torque controls are probably the actual driver and TPS is a side effect. PV/correction tables work somewhat because they modify the input side, which effects everything after, but will still be limited by output controls.

For MT swap, might just be clutch switch or some status bit value missing or lack of any TCU controls altogether now. I doubt there is any radical difference in IJ's that would account for it, the major change was taking the TCU and the more cumbersome AT itself out of the loop.

From what i've found, a retune of the dme usually fixes the issue and gives normal throttle operation. It was my second manual swap so far and the first one had the same "issue" until I reflashed the dme.

Reading the technical documents a little more, LSD or Load Shock Dampening is for positive load change, while DASH or Dashpot, is for negative load change.

I disabled both on my current car as I personally enjoy the raw engine feeling at the cost of more driveline stress

@carabuser any other calibrations or bits I should try since I'm manual? I'll have a look at more BMW Layer calibrations in the damos later

 

[carabuser]

It would be possible to change the settings of the damping rather than turn it off but I haven't defined them.

I have lots of stuff that i've experimented with, not sure how much is of interest, you could try the cat efficiency monitoring tables that I can send you that might help you pass readiness.

 

[JohnDaviz]

It would be possible to change the settings of the damping rather than turn it off but I haven't defined them.

I have lots of stuff that i've experimented with, not sure how much is of interest, you could try the cat efficiency monitoring tables that I can send you that might help you pass readiness.

I am highly interested. Could you share these tables with me?

Both the dampening and cat efficiency monitoring

I would love to test reducing the dampening.

 

[KClemente]

I am highly interested. Could you share these tables with me?

Both the dampening and cat efficiency monitoring

I would love to test reducing the dampening.

It would be possible to change the settings of the damping rather than turn it off but I haven't defined them.

I have lots of stuff that i've experimented with, not sure how much is of interest, you could try the cat efficiency monitoring tables that I can send you that might help you pass readiness.

I've already experimented with the cat efficiency about a year ago. With the right settings it'll work just fine. No more dp fix needed forever

That said, tampering with emissions products to pass state testing is hyper illegal and I don't endorse it

 

[carabuser]

I've already experimented with the cat efficiency about a year ago. With the right settings it'll work just fine. No more dp fix needed forever

That said, tampering with emissions products to pass state testing is hyper illegal and I don't endorse it

I've heard that a few times, everyone is worried about the legal aspects of it but it's no different than using a DP fix.

I just did it out of curiosity, there's no readiness testing in the UK.

 

[AzNdevil]

iirc the anti-jerk related stuff messes with the timing when you lift off the accelerator pedal, it smoothes out signifigant timing reductions in the map and doesnt throw you around. with it disabled, imagine you are in a 90s jap car with a manual transmission, drive in 1st, accelerate then lift off the accelerator pedal, get back on it

i am running antijerk disabled (theres a coolant temp and a rpm threshold) and zeroed out thorttle correction tables, it makes the throttle very responsive just like a cable throttle at the cost of comfort and drivetrain stress

this would be fine on a 6mt but it may potentially cause issues with 6at/dct boxes as the throttle correction tables may be part of the strategy to smooth out gear changes

 

[Bf33meister]

Could someone please direct me to where I can find an .XDF with the throttle tables that are in the tunerpro screenshot in post #4 by KClemente, I have tried searching around but haven't found anything. I have attached a screenshot of the tables I have in my .XDF, it is missing many of the tables that seem to control the throttle actuation. I have already used the Throttle Correction .XDF and it seems to have helped but there are still scenarios where the throttle seems very delayed, mainly when the tires are spinning and I lift off the throttle, it continues to spin like I'm still on the pedal for another .25 to .5 of a second before it does a gentle roll off. It can be quite scary and dangerous depending on the conditions and generally takes away from my confidence in the car. My car is a '10 335i 6mt. Apologies in advance for the slight hijack and big thanks to all who are helping advance the platform.

 

[General.Massacre]

Hi there, attached is the IKM0S Throttle Correction tables

EDIT: I didnt really pay attention to the above, but some XDF are not public and will not be available to everyone but a select few.