A8 D3 4.2TDI remap

[ainarssems]

Before I get on to D3 I will start with a bit of background.

My first adventure into the remap was with C5 A6 in 2011. It was a bit of the task as the EDC 15VM+M ECU found in 2.5TDI is not well documented and also the engine is not known to be most reliable. Anyhow after the lot of time spent researching and lot of trial but not that much of error I did tune it to estimated 225HP and 445Nm from the stock 180 and 370, it was never tested and verified so could have well been a lot less. The way I tuned it and asked some more experienced tuners to review it definitely raised some eyebrows and many said it's a sure way to blow up the engine or melt turbo.
I made it more like petrol engine and raised rpm, the stock max torque is 370 Nm 1.5k rpm to 2.5k rpm, I made it about 445Nm 2.5k to 4.4k and the stock was severely cutting power at after 4.4k but my tune was still going strong to 5k and then cutting at 5.3k. Here I am 9 years later still running fine with 100k on the engine since the tune and almost 250k total which is almost unheard for early V6 2.5TDI without roller rocker arms on the factory camshafts as most fail well before 150k and many even before 100k. Obviously cam wear has nothing to do with tune but still great effort from the engine and while the cams are quite worn by now I have again modified tune slightly to help with air delivery and also lowered smoke limiter to help with torque before the turbos kick in as I do not really care now if the car blows up as it's £500 worth at best now and I would rather send it off with fireworks than scrap it because it cannot pass MOT because of rust or too much suspension problems.

Now back to D3. I have looked at several options including tuning box, generic remap, custom over net, rolling road map and DIY. I am not going into too much detail at the moment but that's a possibility if anyone wants to hear about my thought process. DIY or semi DIY was always the front runner because of cost. I had to upgrade my tool as my last £6 tool I used on A6 would not do D3 so I bought a clone FG Tech V54 for £38. Just to be clear I am not promoting any pirated/clone tools and anyone should decide for themselves and realise that if something goes wrong you are on your own. But paying £700-4000 for a genuine tool is also not what you want to do for 1or 2 of your own cars so may be better to take them to professionals.

Anyhow I have secured several tuning files for 4.2TDI for different soft versions (attached). I have 382247 in my car, I have attached stock and stage1 files for this from online tuner, the tuned file cost me £15, the tuned file should be good for 770Nm, 370HP. The other soft version 392905 tuned by Swiftec should be good for 800Nm, 380HP, I got this online for free.

I have had a quick look at both and I do see some differences in approach between both in boost pressure and also fuel rail pressure. I have not spent much time reviewing them. But I will certainly be combining info from both and then pushing it a bit. The 382247 stage1 provider suggested 750Nm and 370HP is the limit for the exhaust and DPF and while he offered a custom map for £45 he said if I push it higher at stock the pressure and
EGT will rise and ECU will cut back fuel and power if EGT gets too high. He can modify EGT maps to ignore it but that could severely reduce life of items on exhaust side like turbo. I obviously take any suggestions on board but there is a difference between going full throttle for 5 sec at 80mph or trying to set a new record on Nürburgring so I will definitely push the limits and aim for 400+HP and 890-900Nm while keeping all stock.