I've been trying to figure out if its possible and how to delay the torque convertor from locking up slightly. I'm hoping yrktreg will cover this off in the performance tune that his been working on which will be the best outcome really 
however If for any reason the performance tune cannot alter TC lock up logic then what would be the best way around controlling it by the means of bypassing and delaying the original TC lockup signal until a speed greater than what is already set?
Since owning the Touareg I've found the TC lockup is really spoiling the drivability of the car, on low to moderate acceleration the TC locks up at around 30-32kms which is almost immediately after shifting into 3rd gear and is far to early in my opinion and creates lug and unnecessary vibration (I'm sure this is all emissions related) . Once the TC has locked and if you put your foot down to accelerate the engine is no where near as responsive as what it can be and lugs as the TC is reluctant to unlock. The result is you waiting for the engine rpm to increase before the engine starts making a decent amount of boost and torque. Currently where the TC locks its exactly at the speed where its most noticeable during slow speed city driving when you are on and off the throttle often, or whilst taking turns in motion or just needing to put your foot down to accelerate whilst in 3rd. This creates a huge amount of lag in 3rd gear if the rpm is low and the TC cannot stall and flare.
I did a short test today to confirm what the acceleration improvements would be like if the TC lockup signal was intercepted, I had removed pins #5 and #6 on the 8 pin transmission plug connector so no current was supplied to the N443 torque convertor PWM solenoid valve. The result was exactly how I thought it would be, no more lag in 3rd gear when the rpm's are low, if you mash the pedal the torque convertor flares to 2900-3000rpm and the Touareg accelerates effortlessly.
Disconnecting the TC solenoid is not what I'm after permanently as that has its own separate issues. There would be more fuel consumption, higher trans oil temps on longer journeys, no engine braking effect and not to mention the trans fault eventually being displayed on the dash for the P2757 after a few key cycles of driving. Some of the logs I had done on VCDS around the TC lock up status shows that the TC solenoid is used a lot more than what I thought displaying, (open = convertor unlocked, slip = modulated to control a certain amount of slip and closed = converter locked.) I observed through gear shifts the TCC solenoid would allow slip during the gear changes above 3rd gear which no doubt smooths the gear changes even further.
So back to it, really what I am after is trying to delay the TC from locking up at a speed greater than what it's currently commanding. As mentioned above during low to moderate accelerator input the TC locks up at around 30-32km and almost immediately after shifting into 3rd. I would much prefer the TC locking around 50km between 4th and 5th gear and hopefully have the flexibility to easily adjust this and find the sweet spot.
I thought about a speed sensing change over relay that monitors VSS, and doesn't allow the original pwm TCC signal to pass until a speed greater than 50km, so anything greater than this speed the TCM would have full control of the TCC open/slip/closed control to maintain the smooth gear changes and control lockup where needed and engine braking ect. The change over relay would also need to have either a resistor or perhaps another N443 solenoid installed so when the speed is less than 50kms the original TCC signal is directed to a dummy N443 solenoid so no fault code is flagged and the convertor can remain unlocked.
Thinking about it more I thought it would have been nice to monitor pedal position so it would only allow the original TCC signal to pass on low pedal input but this might start getting to complex.
Ultimately I hope Joe gets all this covered off in his performance tune so this is more for thinking outside the box and if there is potentially another solution that will control just the torque convertor control side of things.
however If for any reason the performance tune cannot alter TC lock up logic then what would be the best way around controlling it by the means of bypassing and delaying the original TC lockup signal until a speed greater than what is already set? Since owning the Touareg I've found the TC lockup is really spoiling the drivability of the car, on low to moderate acceleration the TC locks up at around 30-32kms which is almost immediately after shifting into 3rd gear and is far to early in my opinion and creates lug and unnecessary vibration (I'm sure this is all emissions related) . Once the TC has locked and if you put your foot down to accelerate the engine is no where near as responsive as what it can be and lugs as the TC is reluctant to unlock. The result is you waiting for the engine rpm to increase before the engine starts making a decent amount of boost and torque. Currently where the TC locks its exactly at the speed where its most noticeable during slow speed city driving when you are on and off the throttle often, or whilst taking turns in motion or just needing to put your foot down to accelerate whilst in 3rd. This creates a huge amount of lag in 3rd gear if the rpm is low and the TC cannot stall and flare.
I did a short test today to confirm what the acceleration improvements would be like if the TC lockup signal was intercepted, I had removed pins #5 and #6 on the 8 pin transmission plug connector so no current was supplied to the N443 torque convertor PWM solenoid valve. The result was exactly how I thought it would be, no more lag in 3rd gear when the rpm's are low, if you mash the pedal the torque convertor flares to 2900-3000rpm and the Touareg accelerates effortlessly.
Disconnecting the TC solenoid is not what I'm after permanently as that has its own separate issues. There would be more fuel consumption, higher trans oil temps on longer journeys, no engine braking effect and not to mention the trans fault eventually being displayed on the dash for the P2757 after a few key cycles of driving. Some of the logs I had done on VCDS around the TC lock up status shows that the TC solenoid is used a lot more than what I thought displaying, (open = convertor unlocked, slip = modulated to control a certain amount of slip and closed = converter locked.) I observed through gear shifts the TCC solenoid would allow slip during the gear changes above 3rd gear which no doubt smooths the gear changes even further.
So back to it, really what I am after is trying to delay the TC from locking up at a speed greater than what it's currently commanding. As mentioned above during low to moderate accelerator input the TC locks up at around 30-32km and almost immediately after shifting into 3rd. I would much prefer the TC locking around 50km between 4th and 5th gear and hopefully have the flexibility to easily adjust this and find the sweet spot.
I thought about a speed sensing change over relay that monitors VSS, and doesn't allow the original pwm TCC signal to pass until a speed greater than 50km, so anything greater than this speed the TCM would have full control of the TCC open/slip/closed control to maintain the smooth gear changes and control lockup where needed and engine braking ect. The change over relay would also need to have either a resistor or perhaps another N443 solenoid installed so when the speed is less than 50kms the original TCC signal is directed to a dummy N443 solenoid so no fault code is flagged and the convertor can remain unlocked.
Thinking about it more I thought it would have been nice to monitor pedal position so it would only allow the original TCC signal to pass on low pedal input but this might start getting to complex.
Ultimately I hope Joe gets all this covered off in his performance tune so this is more for thinking outside the box and if there is potentially another solution that will control just the torque convertor control side of things.
