How to: GTI Swap

January 17,1998

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 pilot bearing.

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 ease.

If you find yourself doing this conversion and need a little help feel free to E-mail me.

David Hammontree

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Tom Carrington