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Old Thu, Jan-16-2014, 04:22:58 AM   #1
p0lar
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Default Throttle Response Modification Howto

This howto will explain how to alter the drive-by-wire pedal to throttle response mapping on the E46 M3 and E39 M5.

The first thing to understand is where to find the configuration values for these variables within your DME. To do this, you MUST know what version your DME is. Please see this thread about how to make that determination.

There are three throttle response curves, Limp, Sport and Comfort, in that order when found in the DME's parameter space. Their locations are listed in the table below.

VersionDME TypeLimp OffsetSport OffsetComfort Offset
211321000502MSS520x414C0x41760x41A0
211321000901MSS520x414C0x41760x41A0
211321001301MSS520x414C0x41760x41A0
211321001401MSS520x414C0x41760x41A0
211321001501MSS520x414C0x41760x41A0
211321001601MSS520x414C0x41760x41A0
211321001701MSS520x414C0x41760x41A0
211322000701MSS54n/an/an/a
211322000901MSS540x41480x41720x419C
211322001101MSS540x414A0x41740x419E
211322001301MSS540x414A0x41740x419E
211322001501MSS540x414A0x41740x419E
211322001701MSS540x414A0x41740x419E
211322002101MSS540x414A0x41740x419E
211322002401MSS540x414A0x41740x419E
211322002601MSS540x414A0x41740x419E
211322002801MSS540x414A0x41740x419E
211323001601MSS54HP0x81FE0x82280x8252
211323001801MSS54HP0x81FE0x82280x8252
211323001901MSS54HP0x81FE0x82280x8252
211323002001MSS54HP0x81FE0x82280x8252
211323002501MSS54HP0x81FE0x82280x8252
211323002701MSS54HP0x81FE0x82280x8252
211325000301MSS54HP {csl}0x81FE0x82280x8252
211325000401MSS54HP {csl}0x81FE0x82280x8252

Typical limp mode curve for the E46 M3:
Code:
0A 00 00 03 00 64 00 C8 01 2C 01 90 01 F4 02 58 
02 BC 03 20 03 E8 00 00 00 2A 00 52 00 78 00 A7 
00 E2 01 2B 01 5E 01 91 01 F4
Typical sport mode curve for the E46 M3:
Code:
0A 00 00 0A 00 32 00 64 00 C8 01 2C 01 90 01 F4 
02 8A 03 20 03 E8 00 00 00 3C 00 8C 01 40 01 EA 
02 80 03 02 03 70 03 B6 03 E8
Typical comfort mode curve for the E46 M3:
Code:
0A 00 00 0A 00 32 00 64 00 C8 01 2C 01 90 01 F4
02 8A 03 20 03 E8 00 00 00 17 00 3A 00 98 01 11 
01 9A 02 18 02 B8 03 44 03 E8
Let's examine the sport mode curve since it's most often complained about. To simplify the meaning of this curve, let's look at it in a more organized fashion:
Code:
0A 00 
000A 0032 0064 00C8 012C 0190 01F4 028A 0320 03E8 
0000 003C 008C 0140 01EA 0280 0302 0370 03B6 03E8
The first '0A 00' denotes the size of the table, meaning it has 10 "x" components and 0 "y" components. Don't worry about this bit, it won't change and is used internally by the DME.

The second line has 10 data points that indicate the location of the pedal in percent from zero to fully-actuated. They are calculated by converting the hex to decimal and then dividing by 10, thus the data points are as follows:
Code:
000A =   10 / 10 =   1%
0032 =   50 / 10 =   5%
0064 =  100 / 10 =  10%
00C8 =  200 / 10 =  20%
012C =  300 / 10 =  30%
0190 =  400 / 10 =  40%
01F4 =  500 / 10 =  50%
028A =  650 / 10 =  65%
0320 =  800 / 10 =  80%
03E8 = 1000 / 10 = 100%
The third line has 10 data points that indicate the location of the throttle with respect to the equivalent pedal point. They are calculated by converting the hex to decimal and then dividing by 10, thus the data points are as follows:
Code:
0000 =    0 / 10 =   0%
003C =   60 / 10 =   6%
008C =  140 / 10 =  14%
0140 =  320 / 10 =  32%
01EA =  490 / 10 =  49%
0280 =  640 / 10 =  64%
0302 =  770 / 10 =  77%
0370 =  880 / 10 =  88%
03B6 =  950 / 10 =  95%
03E8 = 1000 / 10 = 100%
Combined, they might look something like this:

Pedal %Throttle %
1%0%
5%6%
10%14%
20%32%
30%49%
40%64%
50%77%
65%88%
80%95%
100%100%

So, as you can see, at 50% of the pedal, the throttle is being told to actuate at 77%. The following graphic illustrates a typical E46 M3 throttle response curve for all three curves.



The largest complaint that we hear is that "Sport mode is too sensitive!" Usually followed quickly by "Comfort mode feels like I'm stepping on a wet sponge."

To fix both these complaints, all it takes is a bit of modification to the third line, the throttle response %.

Here's a throttle response curve that I worked up for comfort mode that eliminates a bit of the 'bottom end sponginess':
Code:
0A 00 
000A 0032 0064 00C8 012C 0190 01F4 028A 0320 03E8
0000 001E 0050 00B4 0122 019A 0218 02B8 0344 03E8
Here's a throttle response curve for sport mode that reduces the sensitivity just enough to make it vastly more useful:
Code:
0A 00 
000A 0032 0064 00C8 012C 0190 01F4 028A 0320 03E8 
0000 0028 0064 00F0 0186 021C 0294 0316 0384 03E8
Both of those modifications can be illustrated by the following chart:



Feel free to experiment with these curves to determine what works best for you, and don't hesitate to post your curves!

------------- ERRATA -----------

There are other influencing factors on the response of the throttle opening amounts other than simply the pedal actuator; thus, simply because the pedal to throttle position curve is modified does not necessarily mean the throttles will be open at that percentage. They are further modified by other algorithms that are tuned for optimal engine operation, such as KF_EGAS_WDK, which will be discussed in greater lengths soon.
Attached Images
File Type: jpg tscurve.jpg (91.8 KB, 1146 views)
File Type: jpg tscurve_modified.jpg (92.3 KB, 1146 views)

Last edited by p0lar; Wed, Feb-05-2014 at 10:43:50 PM.
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Old Sun, Apr-05-2015, 12:30:21 AM   #2
rilla
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Default Re: Throttle Response Modification Howto

Quote:
Originally Posted by p0lar View Post
------------- ERRATA -----------

There are other influencing factors on the response of the throttle opening amounts other than simply the pedal actuator; thus, simply because the pedal to throttle position curve is modified does not necessarily mean the throttles will be open at that percentage. They are further modified by other algorithms that are tuned for optimal engine operation, such as KF_EGAS_WDK, which will be discussed in greater lengths soon.
I loaded both of your maps and really like the feel of the revised comfort mode. It's a subtle difference but noticeably more linear that stock. Regarding your statement above, I expect that two modes do open the throttle to the specified percentage but the sport mode just reacts faster without as much smoothing effect as comfort mode.
Even with the toned down sport curve, I still find that mode too twitchy. I may experiment with the same curve for each mode and see how different sport mode feels.
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Old Sun, Apr-19-2015, 09:07:25 AM   #3
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Default Re: Throttle Response Modification Howto

Quote:
Originally Posted by rilla View Post
I loaded both of your maps and really like the feel of the revised comfort mode. It's a subtle difference but noticeably more linear that stock. Regarding your statement above, I expect that two modes do open the throttle to the specified percentage but the sport mode just reacts faster without as much smoothing effect as comfort mode.
Even with the toned down sport curve, I still find that mode too twitchy. I may experiment with the same curve for each mode and see how different sport mode feels.
I agree the comfort mode is much better with this change. Sport mode seems a lot better too, but I never really had any problems with it in the first place, it does feel a lot smoother now though.
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Old Tue, Jun-09-2015, 02:13:50 AM   #4
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Default Re: Throttle Response Modification Howto

I drive in sports mode all the time with these mods, much better than stock. Thanks for the excellent work
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Old Sun, Jun-21-2015, 12:50:41 PM   #5
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Default Re: Throttle Response Modification Howto

any one got a custom throttle map that provides more sensitive linear response. the map above doesn't have that initial kick. seems like it takes a second to really kick in..
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Old Sun, Jun-21-2015, 02:26:54 PM   #6
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Default Re: Throttle Response Modification Howto

Why not just create your own?
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Old Sun, Jun-21-2015, 07:31:12 PM   #7
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Default Re: Throttle Response Modification Howto

That's an option. Saw the tool you created that could be used to easily do this. Wanted to see if anyone had a preferred map before I go through the trials.
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Old Sun, Jul-05-2015, 07:19:53 PM   #8
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Default Re: Throttle Response Modification Howto

Thanks for this P0lar
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Old Fri, Aug-07-2015, 11:55:10 AM   #9
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Default Re: Throttle Response Modification Howto

This is only throttle demand mapping, is there anyway to get to the FWB actuation tables?
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Old Thu, Aug-20-2015, 01:16:24 PM   #10
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Default Re: Throttle Response Modification Howto

Hi, when looking to make the comfort mode as close to linear as possible, I noticed the 1% pedal is equivalent to 0% throttle. Any particular reason for this, why not 1% throttle?
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Discussing Throttle Response Modification Howto in the Coding and Tuning Forum - Discuss all avenues of coding and tuning here! at BMW M3 Forum.com (E30 M3 | E36 M3 | E46 M3 | E92 M3 | F80/X)