How to: GTI Swap
Several list members have asked me questions concerning this conversion, so
here it is.
I used an 82 Vanagon diesel Westfallia and an 86 Jetta GL. I am very pleased
with my results. In the past I have owned a 1980, 2.0 liter aircooled Vanagon
for about a year and a half, and I drove the 82 diesel for about a year and a
half. The Vanagon/Jetta has alot more power and torque than either of these
two vans. Last week I purchased my first wasserboxer, an 87 Vanagon GL.
Right now I am in the middle of rebuilding the 87 Vanagon engine. I have
cleaned and torn down the engine and all the parts for reassembelly will be
here tomorrow. I have never driven or owned a wasserboxer before and I am
really looking forward to it.
If you do this project I recommend buying an entire Golf or Jetta if you can.
This way you know that you will have everything you need for the swap. If
you can't do this you want to make sure you get ALL the pieces ie. fuel
injection system, ignition control unit, idle boost control unit,
relays,computer, etc. Make sure you get everything you will need.
I used the CIS-E fuel injection system. This is alot harder to setup than the
CIS injection system but, if you can do it you will get better performance out
of the engine. This is why alot of people who do the swap use the 83 & 84
GTI, because it uses the CIS system and it is easier. However, the basic part
of CIS-E is mechanical, electronic control regulates a large part of the fuel
pressures and fuel mixture and consequently the running condition (Haynes,
93). Behind the left tail light on that little shelf l mounted the fuel
injection relay, idle boost control relay, fuel pump relay, ignition control
unit, and the computer. I also put a junction box on that shelf which
connects all of the electrical connections. I bought it from NAPA and it is
the perfect box for this job.
The battery in the diesel van is located in the engine compartment. I moved
it up front, under the passenger seat to create more room in the back. You
will need all the room you can get in the engine compartment. In the right
rear I cut out the battery tray and lowered it, making a shelf that I put the
fuel distributor on (Front is Front). Placement of the fuel distributor will
depend on which intake manifold you use.
The fuel lines were a big headache! You need five lines, four form the fuel
distributor to the injectors and one from the fuel distributor to the cold
start valve. All the lines from the Jetta are to short from where you need to
put the fuel distributor. So you need to have them made or make them
yourself. To have them made it was going to cost me close to $200. I made
them myself. The Jetta lines are plastic with a metal braid wrapped around
the line. I Peeled back the metal braid, cut the plastic and pulled out the
banjo and injector connections. I found some high pressure line at Mustang
shop. This line had a metal braid on the outside with a rubber core. This
stuff is not easy to find and cost $8 a foot. I bought five feet and had them
cut it into ten six inch sections. Using the ten pieces of fuel line that l
had bought, I placed the ten banjo and injector connections into each of the
pieces. I used brake line for the length of the injection line and shaped the
brake line in a neat, orderly fashion from the fuel distributor to the
injectors. On each side of the line I put a small clamp on the braided rubber
line where the brake line and connector were inserted. It works and looks
very good. These lines carry 65 PSI of gas. So you need to make sure you use
high pressure lines and you do a good job.
If you use an A1 Rabbit engine, like the 83-84 GTI, the throttlebody opening
will point to the front of the van. On the A2 intake manifold (models like
the 86) the throttlebody opens facing the rear of the van. I recommend using
an A2 intake manifold for a few reasons. The two best places for the fuel
distributor are in the right rear or the right front of the engine
compartment. If you use the A2 manifold place the fuel distributor in the
right rear conner. Use 3 inch PVC tubing, route it from the throttlebody to
the right rear, placing the tube tightly under the rear lip of the engine
compartment. When you check your oil you should be able to see the bottom
half of the tube. Using this setup place the resivor in the front right
corner. If you use the A1 intake manifold you will route the air duct from
the throttlebody over the transmission bellhousing to the front right corner.
If you do this you will need to find a new place for the resivor. Placing the
fuel distributor in the rear right and the resivor in the front right really
makes a great setup.
Now the subject of the throttle cable. The cable starts at the gas peddel,
travels under the van and the end of the cable points toward the rear. On the
A1 throttlebody the end of the cable needs to point toward the front of the
van for it to work properly. I guess you would rig up a pulley system. With
the A2 intake manifold no modifications are needed to direct the cable.
Reguardless of which manifold you use the cable will be to short. Get the
throttle cable from the Rabbit and use cable clamps to make it long enough. I
feel the A2 intake manifold makes for an easier, cleaner, and better layout
of the engine compartment.
Do not install the engine with the intake manifold bolted on. The angle that
the engine sits in the van the intake manifold will hit the left wall of the
engine compartment. It does not matter which intake manifold you use, it is
going to hit the wall. Install the engine and then put the intake manifold on
as best you can and see where it hits. I had to cut out a six inch by six
inch section. I also had to take out a three inch by three inch section in
the frame. More than likly you to will need to cut a hole in this wall. I
have talked to other people who have done this swap, and everyone I talked to
said that they had to cut a hole. Some people said they knew someone that
took a big hammer to the wall and dented it enough to make the fit. I tried
using the hammer first, it didn't work.
You can use the diesel exhaust manifold but, I don't recomend it. It is very
constrictive for the 1.8 engine. If you do use the diesel manifold the
exhaust system will bolt up without any modifications. The problem is where
the downpipe bolts to the manifold. On the diesel manifold the hole is very
small, about 3/4 of an inch smaller than the Jetta GL manifold. This may not
sound like alot but, 3/4 of an inch here will rob you of a handfull of horses.
The GL is the best manifold that will work for the conversion. The 4 into 2
GTI exhaust manifold has the best air flow. I tried to use it but it is to
bulkey and the engine support prevents it from bolting up. This is weird but,
some GTIs use the 4 into 2 manifold, and others use the same manifold that is
on the GL. I think it depends on which factory the car came from. With the
GL exhaust manifold you need to weld a new downpipe to the muffler. No big
deal, any good muffler shop should be able to do this.
The transmission to use comes from an aircooled Vanagon. This transmission
works very well for this conversion. The diesel transmission might work if
you change the fourth gear. If you use the diesel transmission get the specs
and compare them to the aircooled. If l remember correctly 1st through 3rd
gear are almost identical but, if you don't change 4th gear in the diesel,
your engine will turn something like 5500 RPMs on the highway. You will need
to use the diesel bellhousing, flywheel, clutch disk, pressure plate and input
shaft. Use the diesel input shaft because it is the correct length. Replace
the throwout bearing and...
Don't forget the pilot bearing! I did. The Jetta does not use one with it's
transaxel. The first time l drove the van it gushed transmission fluid from
the bellhousing. l took the transmission out and replaced the seal around the
input shaft. Again l ran the van and it leaked transmission fluid from the
bellhousing. Then l realized it was the pilot bearing. Don't forget the
The cooling system you can figure out on your own. I took the old hoses up to
NAPA, matched up the sections of hose that l needed. This worked for me. One
hose that you will need is the one that goes from the water pump to the
resivor. This hoes is bigger on one end than the other. I had a hard time
finding the hose that works here. It is from the VW Fox and it works perfect.
That is about it. Use the diesel oil pump and pan. You probably want to
change the timing belt and water pump when you have the engine out. I did a
complete rebuild job: main and rod bearings, rings, gaskets, seals, head work,
the whole nine yards. Since I had it out, it was going to be much easier to
do it now, than latter. This project was a little harder than I thought it
would be. That is because there were so many little things that I had to
figure out on my own. Once you get it set up properly its hard to beat it.
I really like the Rabbit engine. I feel it has proven itself as being both
strong and reliable, for it has been around close to twenty years. The thing
is nearly bulletproof and when it does break I can always fix it with relative
If you find yourself doing this conversion and need a little help feel free to
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