AAZ Vanagon finally going TDI but which one AFN or AHU? - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• AAZ Vanagon finally going TDI but which one AFN or AHU? by RockOcean on 14 Feb, 2026 17:01
• Hi ya'll been awhile. Some might remember my AAZ rebuild while broke down in Maine wow 14 years ago now.
  
  Well I am ready to finally make the jump to a TDI. Now living in Southwest Montana the AAZ just isn't enough for me going up all the high passes so often.
  
  I am debating on weather to go with an AHU or AFN TDI and have few questions mostly if I go AFN.
  
  If going AFN will the VNT turbo work with the motor mount that I have? In the past it was commented on that I have the best mount for running bigger turbos. But I do not remember the exact details on what was said about it.
  
  Here it is if someone could tell me if a VNT will work with this mount without any modifications or what makes it better then others?
  
  Vanagon Diesel Mount by RockOcean.com, on Flickr
  
  
  If running a VNT turbo needs a custom mount or a bunch of other custom work could I just run my AAZ K03 Turbo on it? I know this will reduce it's performance but I am just wondering if it would work? If I wanted to go that easier route instead of doing a bunch of other custom work for right now. Later in the year I would do the custom work for sure. But I wanna drive across the country in two months so I don't have too much time to get this done.
  
  I think that I want to go the ECU route since finding a reliable mTDI pump for under $1000 seems to be a hard thing to do?
  
  If I do go ECU will an AHU ECU and wiring harness work on the AFN? And can it be tuned for whatever setup I end up going with?
  
  I feel like just going AHU would be the easiest route since I could use my turbo and not worry about other custom work needing to be done. But I can't resist going AFN so I can get the better turbo, injectors, and pump for 22% more power to move my brick up mountain passes.
  
  If I did go mTDI Pump what all is needed for that again? I have the bigger hole AAZ Pump Bracket which I think is needed? What else would I need? Do the AFN/AHU fuel lines work?
  
  I think that's it - if there is anything else I need to look out for or any other recommendations for a  AAZ Vanagon to TDI upgrade please let me know :~ )
• #1 by ORCoaster on 14 Feb, 2026 17:26
• Can’t be of much help to you as I have not dipped toes into this pool. Just nice to see some old members coming back after their given sabbatical.
• #2 by fatmobile on 16 Feb, 2026 22:25
• There are some picture of a VNT-15 on a rabbit in this post:
  https://vwdiesel.net/forum/index.php/topic,47136.msg366436.html#msg366436
  
  Should give you some idea.
  Hard to tell how far forward or back your turbo sits from that picture.
  The VNT-15 does hit the rear motor mount on a MK2, and it bolts to the same place on the block as your mount.
  
  And there's a picture of the special mount I had to make for the VNT-15 in a MK2 in this post:
  https://vwdiesel.net/forum/index.php/topic,46467.0.html
• #3 by BleachedBora on 24 Feb, 2026 11:10
• Completely different beasts. AFN has the VNT style turbo, and you need an updated ECU as well as the boost regulation (N75's) from an AFN. It's cool, has better fuel economy, more power potential, but definitely more work to make happen.
  
  I'd personally say go with AHU, super easy management, everyone knows them, and you'll have less overall headaches.
  -BB
• #4 by RockOcean on 24 Feb, 2026 11:25
• Hiya!
  
  As an update I ended up going with a JX manifold with an adaptor plate (by Tim Shettle) to run the VNT15 or VNT17 turbo in the future. This will clear my early diesel carrier bars and work with the mount bracket that I have. Also will use the Turbo Exhaust Adaptors (also by Tim Shettle) so I can run the stock JX downpipe (sideways pipe on a Vanagon lol) which I am going to run straight out the back thru the bumper like a school bus.
  
  I'm doing a stand alone wiring harness from Fast Forward Automotive in Canada using an ALH ECU tuned for 122hp & 200ft/lbs
  
  I am hoping to run a Mk4 TDI instrument cluster from Andy and Syncro Sport in the UK but can not get a hold of them. I love this since I drove a 2003 Eurovan 10 years before I bought my Vanagon so that will be nostalgic for me :~ )
  
  Also doing the TDI Input Shaft so I can run the Mk4 DMF and Clutch .
  
  Will share photos of the build when the parts start rolling in. Engine gets here on Thursday!
• #5 by fatmobile on 25 Feb, 2026 18:14
• Nice, looking forward to pictures.
  So which engine did you decide to start with?
  
• #6 by RockOcean on 25 Feb, 2026 18:44
• I went with the AFN for the better injector nozzles, VNT15, and stouter IP.
  
  It arrived from Quality German Auto Parts in LA to Southwest Montana in 2 days!
  
  I had it shipped to my grocery store in town. And a friend picked it up for me. Will unpack it tomorrow!
  
  ae7622ff-8e4e-4e6a-9873-60b8442d6736 by RockOcean.com, on Flickr
  
  88649ca0-9912-4ca2-974d-16ac2ff097b8 by RockOcean.com, on Flickr