TDI conversion

[Eric S]

*raises hand*

Well, not *done* doing my own, but currently own a converted car. (see sig).

David Marshall (the guy who does the harness conversions) is hands down
one of the most knowledgeable guys in the wiring department of these
engines.  There ARE some considerations that can make it difficult or
easy.  Last I heard though, David is refusing to do harnesses for anything
but Vanagons now, so you'd be on your own adapting the TDI harness to your
car.

Contrary to what someone else posted, you don't have to change the fuel
lines or tank...just need to find a filler neck with large enough hole, or
cut out (as some have done) the stock restrictor in your filler neck. 
Remove the stock fuel pump and just plumb some straight through line in
place of the pump/accumulator, add a fuel filter, rip out all stock gas
emissions equipment, etc.  Its not as terrible as it sounds, cause you are
mostly removing uneeded items.

Now, obviously, you'd need to start with a 4cyl car, since the trannies
have different bellhousings...though there were some 5cyl TDIs (the AEL
code from euro audis) for sale here in the states recently.  Cost of a
good used 4 cyl TDI is around $2000-2500 including everything you need
(later TDIs will require aquiring the instrument cluster, key and key
reader from the donor car...anti theft system).  Easiest motor to swap is
the 96-97 Passat and 97-98 Jetta engines, engine code AHU.  Those lack the
anti-theft annoyances of the later engines, and have a few different
things on them that make them  more reliable in my book (normal wastegated
turbo instead of a VNT, non-Bosch MAF).

So, as for your cost question, that all depends on if you want used or
new, but ranges from $2000 (low side, high mileage used 4cyl) to $5500
(new 4 cyl or used 5 cyl).

Wiring:  You are not on your own, lots of good people over on
"TDI-conversion at yahoogroups.com" to ask about wiring, including David
Marshall posting there daily.   But, that will be one of the harder things
of the swap, just have to be careful and work through the harness in a
methodical manner and hook things to the right places on your harness.

Gearing, someone else mentioned this.  This could be a large issue for
you.  You need to find gearing that keeps you at 3000 rpm or so while at
highway speeds in top gear.  The TDI redlines at 4500, and isn't making
didly for power after 4000.  Many of the vanagon guys just put taller
tires on to make up gearing...don't know how feasable that would be on
whatever Audi you are considering the swap into.

Lastly, performance:

Yes, there are lots of easy things to do to get more power.  Chip alone
will not get you to 130hp...close, but not quite.  My Corrado is running
the euro .205 injectors (from 110hp motor) and the 11mm injection pump
from a US Automatic TDI....getting around 130-140 with that combo, no
chip.  Able to out run VR6 and G60s with ease, while getting 47mpg
average.  Learning to shift at 3000 rpm is a little difficult, but results
in best mileage and acceleration.

-- 
Eric
www.vintagewatercooleds.com

1981 Scirocco S (TDI swap project)
1988 Audi 90 Quattro
1990 Corrado TDI
1991 Cabriolet (2.0 crossflow 8v project)

David.Payne at brinksinc.com said:
> If anyone has done a TDI conversion on a gas engined car?  What kind of
> cost and electronic headaches?  What rpms is the TDI happiest?  I've found
> a vanagon specialist in Canada that does conversion harnesses.  It
> wouldn't
> be hard to equal the 130 hp that my 10v 90q has and should get 40+ mpg
> plus
> 170+ lbs/ft.
> Feel free to contact me off list.
> Dave.
>
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