Throttle sensitivity tables for n55?

[wheela]

A while back, they discovered throttle sensitivity tables for n54, which fixed the slow revving issue (it wasn't due to "heavy" stock flywheel, it was due to this table intentionally slowing things down). Here's a thread with details:

N54 Throttle Sensitivity Discovery thread

N54 Throttle Sensitivity Discovery thread

www.e90post.com

I understand that MHD has since built in flash time options (for n54) to adjust these tables for customizing how quickly your engine responds to inputs from your right foot.

Is anybody aware of analogous tables for n55? I've searched a bit for threads about this for n55, but haven't had any luck.

Please note - these are NOT pedal mapping tables; these would be different tables that control how quickly the targets in pedal mapping are reached (sensitivity of how quickly the engine reacts to inputs from the accelerator).

Anybody know anything?

 

[carabuser]

The throttle response is two part thing. The rate at which the throttle plate moves is quite minor and only really alters the pedal response at low load since above a 100% load request the throttle will be commanded fully open anyway. The torque target rate of change is the main thing you'll notice when hunting for pedal sensitivity changes.

The overview of pedal mapping is:
1. Table that translates the pedal position to a torque request
2. Routine that converts that torque request into individual torque requests for a) ignition timing and b) air (boost target and throttle position)
3. Routine that handles the rate of change of those variables. So how fast the target torque for ignition can increase.

As you can imagine, there's quite a lot of tables in there. For example, in step 3 there are about 20 tables that handle that rate of change.

 

[wheela]

Thanks for that information. It seemed like people were getting good results just by modifying the tables listed in that thread, but it sounds like there has been a lot of learning since then. Would you lump the tables in that thread into step 3 above? Are there now better ways to improve throttle response (or more accurately torque response) than just modifying the tables in that thread?

For me, I'm 6at transmission, and the biggest behavior I'd like to change is hitting the accelerator from a stop. Slowly leaning into the pedal seems to get the best response (little perceived delay from pedal inputs) - vs. pushing the pedal quickly seems to add delay/damping proportional to how quickly your press the pedal. So the faster you push, it feels like a bigger delay in getting torque.

I haven't found any threads where people have discovered how to address this with n55.

 

[carabuser]

I think both the throttle rate of change and torque damping tables are both useful that that purpose. That's how BMW did it with the 1M.

I don't have a disassembly for the n55 but i might be able to find some of the tables you need if you send your bin file.

 

[Traf]

I think both the throttle rate of change and torque damping tables are both useful that that purpose. That's how BMW did it with the 1M.

I don't have a disassembly for the n55 but i might be able to find some of the tables you need if you send your bin file.

Thats what i wanted to say, when i switched to IKM0S en zeroed all the throttle corrections tables the difference was insane. Zero filtering on the pedal.
Speakig of which, @carabuser do you happen to have the torque damping xdf for I8 and IJ ?

 

[wheela]

I think both the throttle rate of change and torque damping tables are both useful that that purpose. That's how BMW did it with the 1M.

I don't have a disassembly for the n55 but i might be able to find some of the tables you need if you send your bin file.

Thanks for the offer! I'll send you over my bin

 

[wheela]

@carabuser Here is my stock bin and XDF from the MHD github. Thanks again for offering to take a peak at this!

 

[carabuser]

That bin looks quite a lot different to the N54. I forgot that Bosch made the N55 DME. All the Siemens DMEs are all so similar that you can find the tables between them quite easily just by looking at the disassembled code but you'd just have to start from scartch with that one.

I think there is a S55 Funktionsrahmen and A2L are public so if you can find it there it should be straight-forward to find it in the N55.

 

[wheela]

That bin looks quite a lot different to the N54. I forgot that Bosch made the N55 DME. All the Siemens DMEs are all so similar that you can find the tables between them quite easily just by looking at the disassembled code but you'd just have to start from scartch with that one.

I think there is a S55 Funktionsrahmen and A2L are public so if you can find it there it should be straight-forward to find it in the N55.

Thanks for taking a peak

 

[carabuser]

I will take a look when I get a quiet weekend. Might be a bit trial and error though as I'm less familiar.

With the Siemens logic you can just compare the normal comfort orientated BIN files from a 335i with the sportier Z4 and 1M variants to see what they adjusted. Is there any similar variations in the N55 world?

 

[fstbtstr]

Thanks for taking a peak

I'd add that you will need to look at the BMW layer N54 FR (or N55 if you have a BMW layer FR for it, I couldn't find one), Bosch layer N55/S55 FR doesn't have this info. Most of the important stuff is not done in the generic Bosch functions, so that S55 FR will not be too helpful in this case.
P.S. I'm not sure if all the requested driver's torque filtering is done in the BMW layer in case of N54, something could be done in the Siemens layer. In that case these functions might be not 100% equivalent

 

[wheela]

I will take a look when I get a quiet weekend. Might be a bit trial and error though as I'm less familiar.

With the Siemens logic you can just compare the normal comfort orientated BIN files from a 335i with the sportier Z4 and 1M variants to see what they adjusted. Is there any similar variations in the N55 world?

Thanks again! I guess the f87 M2 may be a good comparison, as that's an M car and is n55 powered.