The ATD could have bigger nozzle and different camshaft injector lobe shape than the BEW.
Before to tune the BEW ECU for the ATD I would look at an ATD ECU for injector duration and timing map.
BUMP for an old thread. Haven't visited this thread in a while.
I don't think the camshaft is any different. I'm not sure about the stock injectors (bodies + nozzles) but the stock rated hp and torque are supposedly identical or similar to the stock BEW ratings (100 hp, 177 lb-ft). The ATD runs just fine with BEW mappings and performance tunes designed for the BEW.
An ATD PD engine is a good way to go as a replacement for a BEW PD engine. Aside from having to swap a few BEW specific parts over to the ATD to complete the installation and make it work with a BEW's ECU, it's a plug and play swap.
The 05 ATD PD JWagen has been running great. It's got around 148k miles on it, 72k miles on the ATD PD engine. At 60k on the engine, I had
mrchill do a timing belt change on it. The ATD uses the same timing belt and associated parts that the BEW uses. I'm keeping the interval conservative because I really don't want ANOTHER

TB failure. To add insult to injury, VW supposedly issued a TSB for the BEW PD engine, recommending the TB change interval be shortened from 100k miles to 80k miles. My BEW's TB shredded at 76k miles and gave zero warning before failure.
Upgrades done since the BEW to ATD PD engine swap:
PD150 intake: I had the PD150 intake installed orginally but had to use the original BEW intake for a while to pass OBD-II to get thru NH inspection. I was later able to install it again (see below).
RC2+ tune upgraded to RC3: The tune was updated at the NJ Dyno Day event in 2010 that was actually just over the state line into NY. I was able to do a dyno before and after the RC upgrade. There was little to no improvement on the dyno due the ATD's stock injectors being maxed out, exactly as Jeff warned me. The tune also took care of OBD-II issues that would allow me to use the PD150 intake again. The PD150 intake was installed when
mrchill recently did the timing belt at 140k miles.
R783 injector nozzles: The car is currently at
mrchill's shop getting R783 nozzles installed, in preparation for New England Dyno Day 2012 (NEDD12) coming up on 11/17. Hopefully I won't need the tune tweaked to dial back fueling to control smoke for normal driving. There's next to zero smoke with the current setup before the nozzle upgrade.
I'm looking forward to getting the car back soon to enjoy the weapons-grade TORQUE.
