TheSamba.com :: View topic - Cost estimate and parts list for Vanagon AHU TDI conversion?

Sat Nov 10, 2012 9:45 pm

I am currently looking to buy a diesel Vanagon and would like to eventually swap in an AHU TDI engine. I've done some research and decided on that engine over the AAZ or ALH for a few reasons. The AAZ is less powerful and efficient and the ALH requires a new oil pan and engine mounts and modifying the engine cover. I am looking for a ballpark cost estimate and parts list to convert. I plan on running a mechanical "hybrid" injection pump (mTDI) to avoid having to deal with electronics and will likely do most, if not all, the engine swapping myself.

Besides the engine, a 80-83 vanagon air cooled transmission, and a converted injection pump what else would I need? Oil pump? Clutch? Pressure plate? Flywheel? What existing parts from the vanagon or tdi donor engine would technically work for now to get the vehicle running and could be upgrading or swapped out in the near future?

How reliable are the AHU TDI engines? I've heard they can be reliable as long as your on top of the maintenance, but I've also heard they aren't that reliable. I'm used to japanese cars that are super reliable.

If there are any existing posts or other forum topics that discuss this please direct me there. I'm looking for as much if as possible.

Thanks for your input!

Sat Nov 10, 2012 10:59 pm

It all depends on how far you want to go. I have over $10,000 into my AHU Tdi swap doing everything myself but I rebuilt every single part of the system along the way. Injection pump, engine was rebuilt (paid to have this redone by a TDI only shop), clutch, transmission, axles, carrier bars, bellhousing, braided oil lines, water intercooler, ecu tunes etc. My goal was to do it right the first time. My donor AHU passat was only $750 but it still added up. You will be surprised at how it adds up. My estimate was $8k but I went over. I don't really care, this is my recreation and I learned a lot and it was fun.

The air cooled tranny is not geared well enough for the TDI. You NEED a .70 4th gear if you want to cruise comfortably at 72-75MPH. I have large tires and would still do a lower 4th if they made one. I ran a DK trans (air cooled) on a 2.0 gas ABA swapped westy I had and it was great there....not a TDI.

In my opinion the AHU is about as reliable as it gets. It is the perfect mix between electronics and old school. I have owned 4 AHU Tdi powered cars and am buying another one this week as my daily driver jetta was recently totalled.

EDIT - I forgot to add that the K03 Turbo that comes on the AHU engine is pretty small. I have run one on my westy for 60k miles now with a very aggressive tune for a K03. It works and is much faster than any suby 2.5 I have been in but it runs out of juice at higher rpms. I have a VNT15 turbo from a B5.5 passat that is going in soon. I think this will be a great match. Malone tuning can alter your ECU so it can control a VNT for a few hundred dollars. I wish I went this way from the start.

Sun Nov 11, 2012 9:49 am

R.J. wrote: I am currently looking to buy a diesel Vanagon and would like to eventually swap in an AHU TDI engine. I've done some research and decided on that engine over the AAZ or ALH for a few reasons. The AAZ is less powerful and efficient and the ALH requires a new oil pan and engine mounts and modifying the engine cover. I am looking for a ballpark cost estimate and parts list to convert. I plan on running a mechanical "hybrid" injection pump (mTDI) to avoid having to deal with electronics and will likely do most, if not all, the engine swapping myself.

Are you planning on building the pump yourself? If not, then be sure to get one from someone who knows what they are doing (prothe/hans diesel is not recommended).

Quote: Besides the engine, a 80-83 vanagon air cooled transmission, and a converted injection pump what else would I need? Oil pump? Clutch? Pressure plate? Flywheel? What existing parts from the vanagon or tdi donor engine would technically work for now to get the vehicle running and could be upgrading or swapped out in the near future?

As outwesty mentioned, the stock geared DK trans may not be what you want longer term. You can use the TDI flywheel/pressure plate and a WBX 228mm disc. Get the correct 36mm oil pump. Other than the existing vanagon mounting/cooling system parts (assuming they are all in good condition) you will need to fab a custom intake, custom intercooler system and custom exhaust.

Quote: How reliable are the AHU TDI engines? I've heard they can be reliable as long as your on top of the maintenance, but I've also heard they aren't that reliable. I'm used to japanese cars that are super reliable.

The AHU is bombproof unless you do something stupid. Performance, fuel economy and maintenance costs are excellent. IMO it is the best engine to install in a vanagon with the possible exception of the ALH if you don't mind messing with the rear deck height. It can be tuned for enough power to wreck the transmission, installed in minimal time and for minimal cost (aside from trans regearing) and gets way better fuel economy than anything else that remotely compares wrt power/cost of install.

Quote: If there are any existing posts or other forum topics that discuss this please direct me there. I'm looking for as much if as possible.

Thanks for your input!

There are many. The search is your friend - it's easier for me if you do it...

outwesty wrote: EDIT - I forgot to add that the K03 Turbo that comes on the AHU engine is pretty small. I have run one on my westy for 60k miles now with a very aggressive tune for a K03. It works and is much faster than any suby 2.5 I have been in but it runs out of juice at higher rpms. I have a VNT15 turbo from a B5.5 passat that is going in soon. I think this will be a great match. Malone tuning can alter your ECU so it can control a VNT for a few hundred dollars. I wish I went this way from the start.

While the VNT15 is a huge improvement over the K03, I still think it's a bit small for an AHU in a vanagon. A VNT17 is a better match, IMO. Spool time is not perceptibly extended, but at full boost the 17 is less labored.

Bear in mind when going with a VNT that, as with all turbos, the center section should be clocked to within 15° of vertical for the supply and return. This is somewhat challenging on a wastegated turbo due to the need for modifying both the supply and return, but it is much more challenging on a VNT because the vane carrier is bolted to the turbine housing and pinned to the center section. For my vanagon VNT installs I made a jig in order to fabricate an adapter that places the separate manifold versions at the proper angle. If using one of the integral manifold VNTs, IMO the easiest way is to drill and tap three new holes into the turbine housing for mounting the vane carrier at the proper angle. Accurate measuring and drilling is essential. Even so, the setting for the max closed position may be altered and need adjustment. Quite tricky. Also, the integral manifold VNT is a severe interference with the stock driver's side engine bracket.

Sun Nov 11, 2012 10:36 am

I have a brand new 1749VA non-integral manifold waiting to go on. I am going run an adapter off of an aaz manifold so I can leave the drivers side mount as is. I have not even taken it out of the box yet but are you saying the center section is pinned ? I was not aware of that so I'm glad you posted.

Sun Nov 11, 2012 11:27 am

That's a VNT17, not 15. Good show.

Yes, center section is pinned to the vane carrier which is pinned to the vane carrier which is bolted to the turbine. As I mentioned, I built a jig to go from the AAZ/1.6TD trapezoidal manifold to the non-integral VNT15/17 and it places the turbo at the correct angle. I also made it so the turbo is flipped around so the compressor is to the front and the exhaust is to the rear (made for easier exhaust plumbing).

Sun Nov 11, 2012 11:30 am

I'm sorry I have the 1749V, not VA which is a VNT15. Should I sell it and get the VA ?

Sun Nov 11, 2012 11:32 am

If it's the actual one you have pictured it's the 17.

Sun Nov 11, 2012 11:41 am

Andrew A. Libby wrote: If it's the actual one you have pictured it's the 17.

I just found that photo on google images thinking it was the one. I have the V, not VA.

Sun Nov 11, 2012 12:08 pm

VA is better. How hard are you going to push it?

Sun Nov 11, 2012 12:15 pm

When I purchased it a year ago I went with the 15 thinking it would be less powerful and easier on the trans. Now I am thinking if I am going through all the trouble of fitting it I should just go with the 17 and try not to drive like an a hole. I do a ton of mountain driving.

I was researching the BV43 turbo and it seems guys are pulling 200HP out of the AHU with them....crazy. What do you think ?

Sun Nov 11, 2012 12:38 pm

Since we're in full bore hijack mode, I have a question for the turbo gurus. I have a KKK turbo originally installed on an OM606 engine that appears to be entirely too small for that application in modified form. I've been considering using it on an mTDI install, but I can't find any specs. Does anyone know anything about this guy? There are no decipherable identifying KKK marks other than MB part #s.

Here you can see how tiny it is compared to a T3 from an OM603:

I've already converted it over to a boost activated wastegate:

Sun Nov 11, 2012 1:00 pm

oops Yeah I did hack this thread. Maybe we should start a TDI turbo options thread.

Sun Nov 11, 2012 10:36 pm

Quote: Are you planning on building the pump yourself? If not, then be sure to get one from someone who knows what they are doing (prothe/hans diesel is not recommended).

I am not building the pump myself. I will have someone do it for me. I've heard Libby Diesel at vwdiesel.net does a good job. Anyone know what he charges?

Quote: As outwesty mentioned, the stock geared DK trans may not be what you want longer term. You can use the TDI flywheel/pressure plate and a WBX 228mm disc. Get the correct 36mm oil pump. Other than the existing vanagon mounting/cooling system parts (assuming they are all in good condition) you will need to fab a custom intake, custom intercooler system and custom exhaust.

Am I better off sticking with the stock diesel transmission and switching out 3rd and 4th or do I need the DK trans and then swap out 4th? What vehicle is the 36mm oil pump from and how much are they?

Are any modifications to the intake or exhaust manifold or turbo needed to fit into a DV?

Assuming I can find a good condition AHU, are there any must-do maintenance things I should do before swapping in the engine?

Sun Nov 11, 2012 10:55 pm

I am Libbydiesel on vwdiesel.net. :D I'll send you a PM with details.

Sun Nov 11, 2012 11:06 pm

Here is the link to the first page of my ALH project: http://forums.tdiclub.com/showthread.php?t=276798
Lots of pictures .......... hours to go thru it all.

And, here is the link to the "feeler" for sale of the 4-speed tranny in the above project. http://www.thesamba.com/vw/classifieds/detail.php?id=1387364

Project cost, rough estimates:
1. Engine and everything that's necessary to do a full blown conversion $3,200 with 129k miles on it (rebuild not necessary). It come out of an '02 Jetta wreck.
2. Transmission upgrade, about $1,200.00 (selling price too)
3. Miscelleanous, about $1,000.00.
4. Other to Van, about $1,200. (tires, wheels, suspension maintenance, etc.)
5. Cost of Van, $530.00 off Ebay.......... Non-Westy!

Mon Nov 12, 2012 7:47 am

Quote: I was researching the BV43 turbo and it seems guys are pulling 200HP out of the AHU with them....crazy. What do you think ?

The numbers are realistic, but I don't believe if you want a reliable vanagon that you should shoot that high. Especially if it is a fully loaded camper. Increasing power always exposes the next weakest link. The vanagon is about as aero as a shoebox and is a bit heavy. Those higher numbers are more suited to lighter aero vehicles. A stock tdi in a vanagon with proper gearing has no problem keeping up with traffic or climbing mountains.

Andy, you did not mention the hours you have in yours. To the thread starter. If you just purchased this vanagon, most likely it will need a ton of other things beyond the conversion. I think the figure of 10K for a completely finished road worthy conversion is realistic for any engine choice. The small parts really add up quickly. Post pictures or it never happened.

Mon Nov 12, 2012 10:10 am

AndyBees wrote:
Project cost, rough estimates:
1. Engine and everything that's necessary to do a full blown conversion $3,200 with 129k miles on it (rebuild not necessary). It come out of an '02 Jetta wreck.
2. Transmission upgrade, about $1,200.00 (selling price too)
3. Miscelleanous, about $1,000.00.
4. Other to Van, about $1,200. (tires, wheels, suspension maintenance, etc.)
5. Cost of Van, $530.00 off Ebay.......... Non-Westy!

You forgot to add the 1000 hours of you time Andy!!!! Just imagine if you had to pay someone for that :lol:

Mon Nov 12, 2012 10:21 am

R.J. wrote: I am currently looking to buy a diesel Vanagon and would like to eventually swap in an AHU TDI engine. I've done some research and decided on that engine over the AAZ or ALH for a few reasons. The AAZ is less powerful and efficient and the ALH requires a new oil pan and engine mounts and modifying the engine cover. I am looking for a ballpark cost estimate and parts list to convert. I plan on running a mechanical "hybrid" injection pump (mTDI) to avoid having to deal with electronics and will likely do most, if not all, the engine swapping myself.

Thanks for your input!

The AAZ is less powerful and efficient because it has a mechanical pump and no computer.

Guess what happens to the AHU when you give it a mechanical pump and no computer.

Get an AAZ and adjust the injection pump. Instructions on vwdiesel.net will easily put you over 100 HP.

Mon Nov 12, 2012 10:26 am

I figure I was about 150 hours in two months to get my ALH conversion driveable. I still have stuff to complete on it but have well over 1000 miles on it so far. It will definitely nickle and dime you to death!

But when I watch my scangauge on the dash read 30+ MPG at freeway speeds, I forget all about the long nights spent working on it.

Mon Nov 12, 2012 12:18 pm

fredn wrote: The AAZ is less powerful and efficient because it has a mechanical pump and no computer.

Guess what happens to the AHU when you give it a mechanical pump and no computer.

That is incorrect in the extreme. The AAZ is less powerful because it is lacking an intercooler and has a DETUNED injection pump fitted which does not give proper boost fuel enrichment. It is less efficient because it is an IDI (indirect injection) engine instead of a DI (direct injection) engine and so suffers an increased heat loss of approx 15% of it's heat energy to the cooling system of the cylinder head resulting in a 10-15% drop in engine efficiency. That 15% of energy is turned into useful work with the T-DI(direct injection) engines.

A properly built mTDI injection pump will deliver as good or better power than the stock e-TDI engine. My AHU in my High Top vanagon gives noticeably better performance than a stock AHU jetta. In fact, the mTDI pumps have the ability to accommodate proper fueling for enough power to destroy vanagon transaxles or even jeopardize the rods of the AHU engine. The mechanical TDI injection pump is certainly NOT the limiting factor for power in a vanagon. I do believe that the electronically controlled engine can deliver slightly better efficiency with it's on-the-fly timing and boost adjustment, but the difference is negligible if the mechanical pump is well-tuned.

If an AHU is fitted with a properly built/tuned mTDI pump and matched up against an AAZ fitted with a properly built/tuned pump and fitted with an intercooler, you will see similar max power from both engines. The AHU will produce that power 10-15% sooner and consume 10-15% less fuel doing so. The AAZ will have the ability to rev higher. They are both great engines. The only real advantage that the AAZ has over the AHU in a vanagon installation is the fact that with its greater rpm range, it is much better suited to stock vanagon gearing matched with larger tires. The downside is it's increased fuel consumption which is unavoidable due to the added surface area and accompanying heat loss of the pre-combustion chamber.