The issue is that almost everything is different between early 2.5 v6 tdi driveline on the b6 and 3.0 tdi on the b7 platform. Different gearbox, different wiring loom, different ecu’s, ABS pumps, etc. physical fitting of parts is just one part of the problem. The 2.5 tdi has also massive tuning potential, 300 Bhp is just a turbo + nozzle swap away. In the OPThe B7 is almost identical to the B6 platform and it houses the 3.0TDI V6 i have a B6 2.5TDI and i think that you will be able to squeeze the 3.0TDI in as it"s size is very similar to the 2.5TDI. And the 3.0TDI has got huge tuning potential as it"s common rail and has got quite a big displacement. I wish you all luck with the project and looking forward to the build thread.
The 2.5Tdi is a very strong engine but the injection pump VP44 is very limited it can't supplie more then 55mg/str because it's limited by the IP ecu. You can put bigger turbo on and bigger nozzles but it want be the same as a commonrail where you can easily adjust the injection quantity.The issue is that almost everything is different between early 2.5 v6 tdi driveline on the b6 and 3.0 tdi on the b7 platform. Different gearbox, different wiring loom, different ecu’s, ABS pumps, etc. physical fitting of parts is just one part of the problem. The 2.5 tdi has also massive tuning potential, 300 Bhp is just a turbo + nozzle swap away. In the OP
Case jumping from a 8 cyl Petrol engine to a 4 pot diesel engine then to a 6 cyl diesel lump is quite a feat ! Hats off to you...
Maybe you could modify the 3.3TDI V8 common rail injection system to work on the 2.5TDI the 3.3TDI V8 is basically just a extended 2.5tdi block it uses the same pistons the heads are longer but the same and the injectors should fit in the 2.5TDI heads you would need to block off the 2 injector ports on the fuel rail and install the high pressure pump in place of the VP44 and modify the ecu system a bit.European B7s (atleast with engines ASB/BKN) 3.0tdis came with Getrag upgraded 466 as under name vag code 0A3, holds holds at least same power and has better syncros compared to 01E. I wouldnt be worried about that. Weaker link IMO is the DMF, since it starts usually stutter past 550nm. Also euro versions ASB and BKN use bosch edc16cp, so siemens probably for over seas or maybe not.
What comes to vp44 its just newer pumps that have heavy duration limiter on their ecu.
It's quite a shame nobody cracked the vp44-ecus since pumps itself are capable well over 600hp. Even with the smallest 6mm plungers 400hp+ is no joke. I like more 2.5tdis since they are more lively and rev happy compared long stroked big brothers. Cr system in 2.5tdi would be something beyond awesome.
You could use a set of 3.0tdi fuel rails and cp3 or cp1 pump. The only problem then would be the ecu because the 3.3tdi uses dual ecu setup and each ecu controls 4 injectors the ecus are identical to what the 2.5tdi uses so you would need to do some rewiring and remaping and it should work in my opinion.
What is the issue the allroad engine doesn’t run ? As diff as mentioned, vp44 pumps can be easily repaired and with 3 plungers head and larger injector nozzles they can inject a lot of fuel. No dpf to worry about, simple electrics, clutches that can cope with over 500 Bhp are readily available but let down by the DMF-it starts to rumble as torque increases. Add a pair of cam roller heads, a modern turbo and a solid inter cooler/4 bar map sensor and it becomes a very nimble car !This is my 2.5 tdi allroad this is one of the only Allroad 2.5 in North America the engine I got was brand new crate engine from Germany it has zero kilometers on it so I figured it should be good for 200,000 kilometers before any serious issues and I will keep the oil changed every 5000 kms with synthetic
I don"t know if the 2.5tdi ecu has the injector drivers but the 3.3tdi injectors are solenoid based but they are working on 80V instead on 12V so each ECU is only able to control 4 injectors. I think that you could use the same dual ECUs on the 2.5tdi because most of the sensors are the same on both engines you would just need to disable two injectors so that there wouldn"t be any fault codes. You can find more about the 3.3tdi engine and injection system here https://drive.google.com/open?id=1t9fJyDA7i5skdw0IisPgTDcT5nva0FlD https://drive.google.com/open?id=1Cie5mY2GKRNhk2blALXiA8qjr1sHfdKXDoes the 2.5 TDI ECU have injector drivers thou ? As it's not required for a rotary pump technically I may be wrong 3.3 TDI injectors I'm assuming or solenoid based so they be easier to control
Later AKE injector pump require immo matching, YOU will need immo code and follow the procedure from Rostech website... you should get it to work...The issue is I swap the car I haven't been able to get it running the injection pump on it was also brand new but this motor sat for 17 years with stale fuel ..... the car is throwing dtc codes for pump communication errors and measuring block 18 shows 0 pump volts also my ECU immobilizer has been deleted so I don't believe they require syncing the pump ???