I just "completed" my CQ to S2 Conversion. I thought it would be nice to compile my experience in one post with everything start to finish.
My goal with this project was to do a quick conversion using mostly OEM parts. The project was 100% funded by the sale of other car parts, non of my actual day job income was used to build this car (except for the cost of the CQ, which actually was funded by a car accident)
I started this project late April early May, however I had already started collecting parts before that time. It was "completed" just a few days ago (I say "completed" because everyone knows a project car is always changing and always upgraded, but the the car was up and running again so thats why I say completed)
Here is my shopping list:
1 Coupe Quattro (this is how it looked when I bought it)
Just before the swap
20vt Engine (I took mine from a URS4 that i picked up cheap and parted out to pay for itself)
ABY Wiring Harness (this is the European wiring harness for the later style S2, I sourced it from Europe along with all of the ABY parts)
ABY Oil feed and Return lines
ABY Oil Pan extension with return hole
ABY Cross Member and Intercooler
ABY Intake Manifold and Charge Pipes
3B Downpipe (I used the 3b because the ABY version has dual cats, 3b has the outlet in the same place as the stock coupe quattro)
Strebro Exhaust (not necessary, I had it in my garage already)
Spec 3+ Clutch and Pressure Plate (stock clutch can be used, but i figured I would upgrade since I had it all apart)
S2 Hubs (again not necessary, a good deal came along and I bought them)
034 Alu Subframe Mounts (not necessary, but again, while in there)
034 Motormounts (most mounts are dead unless they have already been replaced)
034 Silicone Boost hoses for RS2 (I needed hoses, I didn't want used hoses that would fail so i bought new, these work great but they do not include the hose to the DV from the charge side of the turbo, they have the hole for it, but no hose, kind of frustrating)
S2/V6 Front bumper (sourced from Europe, the later style v6 bumper is the same as the s2 but without headlight washers. This is necessary if you have the OEM crossmember and intercooler, it allows space for them)
RS2/ABY Fuel rail
7A Harmonic Balancer (I had a spare in my garage, but you can take yours from the stock engine)
7A Flywheel (you can use the AAN Flywheel, but it is a "Dual-Mass" you will need a spacer between your engine and the bell housing)
Custom Fuel Lines, I had VAP AKA Mance make mine
3B or ABY Water manifold+ 7A water housing (the silver guy above the alternator in this picture)
7A brackets for your accesories (PS Pump Bracket, Alternator Bracket, AC Bracket (if you go that way))
Random hoses, vacuum lines and lots of clamps.
Started by removing donor engine from donor car (left the cq untouched so I could still drive it)
Moved the engine to a stand for clean up and for mounting all of the correct manifolds/ accessories
I also installed an 034ms Phenolic Spacer, keeps temps down, it is really nice product.
with rail in place
Stripping the CQ:
I removed the Heaterbox, however this doesn't need to be done, I was swapping in a Manual Box since I hate the Auto CC that came in this car.
I later removed the Battery tray, that is where the intake charge pipe runs, so it is kinda in the way.
I relocated my battery to the trunk, i used the stock wiring from the URS4(the battery location for that is under the seat) this wiring actually has two main parts from the battery, one that runs to the fuse box, one that runs under the hood. the one that runs under the hood actually splits at the firewall and has a "positive post" to run power or for jump starts, and then the second wire runs to the starter.
Wiring, not fun but can be done. I contacted Paul of S2Central, and he ended up making a PDF File that shows every connection, and where it goes what it is for. It was a life saver http://s2central.net/main_frame.html
Honestly, the wiring was the part that scared me the most, however with the pdf file i talked about it was a breeze.
Once the engine was in its new home, I changed out the harmonic balancer, mine was over torqued and I didn't want to do it on the engine stand.
Everything hooked up as it should, in the engine bay the only thing that i needed to change was the connection for the reverse light, the transmission had a different size plug, i could have just cut and spliced, however I wanted to keep the harness in one piece so I actually made an adapter to go between the old connector on the transmission and the new connection on the harness. I ran a new ground wire from the block to the motor mount.
There are a few small connectors inside the car that did not hook up as planned, but it runs without them.
The water line to the turbo didn't match up, it was in the way of my PS pump so I had to make an adjustment:
This is how the stock aby hose is ran, you can actually see it cut out in the timing belt cover to make room for the hose to be re-routed.
After getting all of the wiring ran and in place, all of the fuse box back how it should look, and getting all of the random hoses and vacuum lines hooked up i attempted to start the car. I turned it quickly to see if the starter would spin, it did, so I turned off the car, turned it on a couple times without engaging the starter to prime the fuel pump and to refill the fuel lines, gave it a turn and it started on the first try. I was pretty surprised and very happy. I would strongly recommend going this route as it was affordable and easy, no drama and it has good results.
*this is a work in progress I'll update and probably change around a few things*