I've been thinking about launch control on the stock ECU for some time but couldnt think of a way to get it to work. i had discovered some information about the coding plug near the ECU AKA the one that normally has a jumper in the USA URS4/URS6 cars for the speed limiter. what i had learned is that if you ground one of the other pins in the connector it makes the ECU switch to a different ignition map! this got my gears turning because i used to do the same thing with digifant 1 ECU's to have launch control on them. i dug out my moates rom emulator and started tracing the maps to see what map the ECU would trace when i grounded different pins in the connector and i found it. my next step was to retard the timing from the set RPM point (4500RPM) so i loaded up tunerproRT and winOLS. after looking at the map in winOLS i decided to make roughly half the map that the ECU referenced 00. once i did that i corrected the checksum with winOLS and saved the new modified file. than i loaded the new modified file into my emulator and tested it out. i got the results i was looking for! so my next step was to figure out a way to ground this pin when i wanted to use the launch control. i remembered how i had setup the launch control in my old GTI using the cruise control button and switch on the wiper stalk along with a clutch switch which i used an old brake light switch for my clutch switch. when i wired it up in the audi it worked just the way i had planned it to, when you hold the set button on the stalk and clutch in the map is switched and launch control is enabled also when you flip on the cruise on switch and clutch in it enables the launch control but also allows you to have a no lift shifting feature as well because the timing is retarded the whole way from the set point AKA 4500RPM the whole way to the end of the map.
Here is a more in depth description of how to do this and what you'll need to get it done.
For starters you must have a modified ECU that has chip sockets installed to do this. I posted in this thread what you have to do to get setup and socket you ECU.
[url]http://www.s2forum.com/forum/showthread.php?t=63826"]http://www.s2forum.com/forum/showthread.php?t=63826[/url]
The next piece of hardware you are going to need is an EEPROM programmer and a electronically erasable EEPROM. i used SST27SF512 chips as they are readily available and cheap.
on the software end your going to need winOLS to correct your checksum or some form of checksum correction for that matter. also i suggest having tunerproRT and the XDF to go along with your revision. in my case i have 4A0 907 551AA ECU and firmware.
to modify the BIN file for the 551AA ECU fire up winOLS and load your binary that you want to use. once you do that locate hex offset 0x955F, this is the map that is used when the pin in the coding plug is grounded.
Here is what the map looks like before changes are made.
you have to figure out where you want to start cutting ignition and thats where i used tunerPRO RT and my XDF file.
Here is the same map in a more easily viewable form before the changes are made.
i looked at the map in both programs and figured out where i wanted my ignition to be cut at and this is what i ended up with. to retard the timing take where you want you launch control to start and make the binary 00 from that point the whole way to the end of the map.
My timing map after i made changes in winOLS.
Here is the real world value and the values in hex in tunerPRO RT just so you can see what changed.
Dont forget to correct your checksum!!!!!! car gets angry without it being right!
with that being said you need to get your new binary on to a chip so this is where the EEPROM programmer comes into play so get the BIN file burned to the chip and install it in your ECU. dont forget to make sure the chip is in the socket the right way, if its backwards your car will not run and could damage your ECU or the chip. with the chip burned and it installed in its new home plug your ECU back in start your car just to make sure everything went well.
The next step is to tie in a wire to the pin in the coding plug. The picture below shows the plug and the pin we need to ground to make the map switch.
What i did was modify an old speed limiter plug so that i didnt have to cut into my harness. This is what the speed limiter plug plug looks like together and taken apart.
This is the plug taken apart and modified.
With that done i plugged it into the coding plug and tied a wire that i ran across the car to my clutch switch AKA an old brake light switch, than from there up to my cruise control switches on my turn signal stalk and than to the grounding crown above my fuse box on the drivers side. you can wire this up however you want to suit what your doing, i just shared how i set mine up because of the sequence you have to go through to enable and disable the feature. my way doesnt mess with normal daily driving if you have the cruise switch off or your not pressing the set button on the stalk. to make launch work you have to press and hold the set button and have the clutch in. to have no lift shift and launch control all you have to do is turn the cruise switch on and clutch in. with the switch on there is no need to hold the set button for launch control.
This is a wiring diagram i created real quick to share exactly how to wire the WOT BOX into URS4 and URS6 cars.
Here is a video of mine functioning on this setup. i have mine set to -22.50 degrees of timing which is the most retard you can get also its set to kick in a 4500RPM. Im making 8 to 10 PSI on this so far but im using the stock K24 as well so that might have something to do with it also i would venture to say the boost chip mapping plays a role in how much boost you can make on this setup.
lastly i hold no responsibility for what could happen to your car during the process of adding/enabling this feature or what using this feature will do to your car. this form of launch control is hard on your car as it basically causes fuel to ignite inside your turbo manifold and turbo thus creating load on the engine and and creating boost while standing still. This will raise EGT's very rapidly which can crack or break your turbo manifold and damage your turbo. If you have a stock exhaust with a cat i suggest you not use this feature as it will most likely melt your cat and or blow the exhaust off of your car. The more free flowing the exhaust the better. The backfiring is extremely loud and will probably make your neighbors and law enforcement very angry with you so use this wisely. with all of that said enjoy having the big bang launch control with your OEM ECU without spending big bucks on a stanalone ECU.
If you have any questions please feel free to ask and i'll try my best to help you out. as for other versions of the I5 20V turbo ECU im not sure which map has to be modified to allow this work. all of the different revisions have different map offsets but if your capable of figuring out how to do this than you can most likely locate the map offset for your specific ECU. also i dont know if this is possible with the distributor driven engines as i dont have one at my disposal to mess with. if it is possible im sure you could figure it out with the info i provided here.
I am from germany and followed you post very interested, here and in the s2-forum.