A little knowledge is a dangerous thing. When paired with Ebay purchases and free dodgy software downloads the combination borders on insanity - but I hope that some folk may find the following informative. 18 months ago when I was having problems with my stock BHC car wheel-spinning on damp roads (crap budget front tyres when bought as well as urgently needed new front shocks) I was discussing remaps with Paul (@depronman of this parish) - who is knowledgeable in this area and asked a question about the possibility to knock up a map that would reduce likelihood of a Tdi breaking traction in slippery conditions - effectively a 'winter' mode. His considered response was that a torque limiter (fuel injection quantity vs rpm) tweak may well be the direction to go if that was the aim. Once I fitted decent tyres that proved to grip in 90% of the conditions encountered here in Scotland, I never went further with the discussion or idea last year but the seed was sown.
Having downloaded the various bits of software (MPPS v13 for transferring maps to and from the EDC15 Tdi ECU, and another one to open them, interpret and make modifications) - and bought the MPPS v13 ODB/USB dongle that allows a PC laptop to transfer maps to and from the ECU I started mucking about the other day with the AMF map from my project car. Again - thanks to Paul for a lot of advice on the following.
The EDC15 (Tdi ECU) has enough memory for two code blocks - ie the extensive sets of maps covering all parameters, normally allocated notionally for manual and automatic vehicles. As supplied, the AMF and BHC have both halves programmed identically, but the ECU is supplied programmed into "code block 2" for manual. And if untinkered with, so it stays.
However, with VCDS or some plug-in readers, it is possible to switch the car over to "code block 5" as if it was an automatic, and make use of the other programme. If you've tinkered with the other programme, then you have the option of swapping between the two relatively quickly (simpler than a full remap that takes probably 10 minutes in ideal circumstances getting equipment into the car and the laptop to speak to the car safely).
I took the original map for my car (downloaded from the vehicle), and having opened this up on the laptop, approached the torque limiter map in code block 5, and took the normal bell-curve-shaped injection quantity giving the normal surge of acceleration from 2000-3000rpm down to a flat line quantity of 35mg fuel per injection unit across the range.
This altered the predicted torque and power curves from the bell shape peaking over 200nM at 2300-2800rpm with power peaking at 82 (75 officially) hp we normally expect down to a ~140nM flatline from idle to red-line, and a linear power delivery curve peaking at 62hp at 3900.
I then uploaded this to the car, and initially ran it in the code block 2. Car ran completely normally (as one would hope). Then switched the car over to code block 5. Car started up completely normally. In local commuting the car drives completely normally part throttle at <40mph - as the driver wish (throttle) map mostly requests fuel injection quantities lower than the torque limiter graph until you get above 80% throttle input across the rev range whereupon the torque limit curve is the red line for injection quantity. The only difference you notice is that when accelerating up a slip-road in wet conditions now giving it some welly, it is a fair bit slower and a lot more linear in terms of gaining revs, and there is no torque-steer at all. Still able to run up to 60/70mph on the local dual carriageway - but obviously, accelerating into a space or another lane to effect a quick overtake is no longer a given. Reminds me of driving an old late 80s Transit 2.3 diesel minibus at University - it will get you there but it takes a bit more planning and looking at your mirrors.
This isn't the most exciting achievement in the remap world - I will openly admit. I'm waiting to see if this has any positive effect on fuel economy (unlikely as I only uploaded it half way through a month running an uprated AMF map to begin with and am also working on fuel gauge calibration - and I'm not Audi's technical centre who optimised the original maps as far as they could have done with the benefit of actually knowing what they are doing). However, I have now answered my initial question - whether it is possible to generate a map that mitigates the potential of the AMF / BHC to break traction in slippery conditions whilst maintaining basic driveability?
The answer is that it is, but I'm having to balance the satisfaction of achieving what I aimed to do with the tedium of turning an A2 into an 80s Transit as far as the fun quotient is concerned.
Having downloaded the various bits of software (MPPS v13 for transferring maps to and from the EDC15 Tdi ECU, and another one to open them, interpret and make modifications) - and bought the MPPS v13 ODB/USB dongle that allows a PC laptop to transfer maps to and from the ECU I started mucking about the other day with the AMF map from my project car. Again - thanks to Paul for a lot of advice on the following.
The EDC15 (Tdi ECU) has enough memory for two code blocks - ie the extensive sets of maps covering all parameters, normally allocated notionally for manual and automatic vehicles. As supplied, the AMF and BHC have both halves programmed identically, but the ECU is supplied programmed into "code block 2" for manual. And if untinkered with, so it stays.
However, with VCDS or some plug-in readers, it is possible to switch the car over to "code block 5" as if it was an automatic, and make use of the other programme. If you've tinkered with the other programme, then you have the option of swapping between the two relatively quickly (simpler than a full remap that takes probably 10 minutes in ideal circumstances getting equipment into the car and the laptop to speak to the car safely).
I took the original map for my car (downloaded from the vehicle), and having opened this up on the laptop, approached the torque limiter map in code block 5, and took the normal bell-curve-shaped injection quantity giving the normal surge of acceleration from 2000-3000rpm down to a flat line quantity of 35mg fuel per injection unit across the range.
This altered the predicted torque and power curves from the bell shape peaking over 200nM at 2300-2800rpm with power peaking at 82 (75 officially) hp we normally expect down to a ~140nM flatline from idle to red-line, and a linear power delivery curve peaking at 62hp at 3900.
I then uploaded this to the car, and initially ran it in the code block 2. Car ran completely normally (as one would hope). Then switched the car over to code block 5. Car started up completely normally. In local commuting the car drives completely normally part throttle at <40mph - as the driver wish (throttle) map mostly requests fuel injection quantities lower than the torque limiter graph until you get above 80% throttle input across the rev range whereupon the torque limit curve is the red line for injection quantity. The only difference you notice is that when accelerating up a slip-road in wet conditions now giving it some welly, it is a fair bit slower and a lot more linear in terms of gaining revs, and there is no torque-steer at all. Still able to run up to 60/70mph on the local dual carriageway - but obviously, accelerating into a space or another lane to effect a quick overtake is no longer a given. Reminds me of driving an old late 80s Transit 2.3 diesel minibus at University - it will get you there but it takes a bit more planning and looking at your mirrors.
This isn't the most exciting achievement in the remap world - I will openly admit. I'm waiting to see if this has any positive effect on fuel economy (unlikely as I only uploaded it half way through a month running an uprated AMF map to begin with and am also working on fuel gauge calibration - and I'm not Audi's technical centre who optimised the original maps as far as they could have done with the benefit of actually knowing what they are doing). However, I have now answered my initial question - whether it is possible to generate a map that mitigates the potential of the AMF / BHC to break traction in slippery conditions whilst maintaining basic driveability?
The answer is that it is, but I'm having to balance the satisfaction of achieving what I aimed to do with the tedium of turning an A2 into an 80s Transit as far as the fun quotient is concerned.