Turbo MC in 80q...My experiences (long)

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I'm sure all of you out there who have ever walked through a junkyard have
seen turbo motors in 5K series cars. If you were like me, you fantasized
about the extra horsepower and performance that the swap would give a small
bodied Audi Q. Well I can testify that the transplant has completely lived
up to the fantasy (with the exception of a few nightmare problems that I
ran into).

I actually bought my 88 80q with this swap in mind. I liked the fairly
modern (not to mention stealth) styling  of the 80/90 series cars. I
decided on an 80q because of the lower weight and less complexity than the
90 cars (80 series have no leather interior or ABS). Before starting the
swap, I wanted to make sure that the chassis was up to the increase in HP.
I went with Eibach/Koni sport. All new bushings and rubber mounts.
Fabricated 3/4" rear anti-roll bar and a Tilton adjustable brake
proportioning valve as well as upgraded pads. (4 pot calipers will be the
next project). I enjoyed the car for about a year with the stock
motor...great snowboarding car but definitely low on power. This post will
illustrate how I did my swap. There are always alternate routes, and
hindsight is 20/20, but for the low amount of money I spent, I'm extremely
happy with the results.

Re-locate the battery. This was needed to clear the wastegate. It also
really helps the balance of the car. I removed the whole battery box where
it is spot welded to the body. The battery fits well in the pass. side
trunk well. I found a battery hold down at the junkyard, drilled 2 holes in
the 80 and bolted it down. I ran the cable up the pass. side where the
carpet meets the plastic cover. It fits under the cover. Then I drilled a
hole under the A/C unit in the firewall. Use a good rubber grommet. Then
connect to a junction block and use to power all the systems.

Find an MC. I found a good running cheap 86 CS with 75,000 miles and great
compression. It was nice to have a running car, as I saved the costs of
towing. Also, I wanted to know what, if anything was wrong with the engine.
I was able to do a compression test and pull the codes BEFORE I bought it.
DO NOT attempt to perform the swap on an engine that doesn't run. You will
introduce so many new variables during the swap that you won't know what
you caused or what was pre-existing.

Prepare to remove the MC. I worked on the 5K for about 2 weekends before I
was ready to pull the motor. I had it steam cleaned. Then I labled
EVERYTHING. A running car also allowed me to experiment with disconnecting
different harnesses to determine which ones were vital. I found in my car
the red and the yellow taped harnesses are critical. Label all connections
from these as a starting point. Then begin carefully removing the
harnesses. Don't leave the coolant after-run harness and equipment behind.

Pull the turbo motor. Hoist is recommended, but not necessary. You can pull
the motor straight out the front after removing the body front end pieces.
Once I had it out, I did the t-belt, w-pump etc.  Clean all the nooks and
crannys. Remove the auto tranny starter ring and pilot bushing. Use a slide
hammer for this. Remove the downpipe, alternator and A/C compressor.

Clutch: Major pain! You 4kt guys have it easy as your clutches are
interchangeable with 5k. 80/90 series clutches are not compatable. I found
out the hard way. Learn from my mistakes. The transmission input shaft is
larger on the 80 than the 5k. There are also offset and pilot bearing
issues to deal with. I ended up using the 80 flywheel, a new 80 pressure
plate, and a friction disk from a 90-91 Coupe Q! This actually worked out
well, as the Coupe disk has the correct splines and the 240mm diameter that
the turbo needs (especially after increasing the boost). The stock 80
pressure plate also has 240mm diameter (odd, because the stock 80 disk is
228mm.) I then had to have the flywheel surfaced to at least 240mm of area.
The final step is to have a Hall ignition timing dowel installed in the
flywheel. I measured very carefully based on where the original auto tranny
starter ring had it's timing dowel. You will need to have about 1/4" of
shoulder machined off of the 80 flywheel so you can install the Hall pin
deep enough toward the pilot bearing. Have the flywheel re-balanced after
all the surgery. Be sure to re-adjust the Hall pick-up unit clearance.
There might be a flywheel out there that has the Hall pin and compatibility
with the MC as well as the 80q tranny. Possibly a Coupe Q or S4? I didn't
even look into it though as I couldn't confirm what would work, and I was
afraid of the cost. My solution worked great for only abut $130 in machine
work. (The key component, the Coupe clutch disk, was $240.00! Ouch. I
didn't know a disk could cost that much! I feel for you Coupe guys. Is that
typical?)

Remove the 80 motor. I pulled mine out the front of the car with a floor
jack. With the motor out I was able to clean up the engine bay and repaint
the section where the battery box was. Don't break your plastic radiator
like I did. (oh well, I can probably use the extra cooling from the new
one.)

Replace the pass. side tie rod with one that clears the wastegate. I
ordered one from 2bennett. They wouldn't modify a used one...they would
only bend a new one. Took about 5 days. No complaints.

Pre-wire the car. You will need to drill about a 1" hole in the firewall
near where the A/C plumbing goes into the interior. This is for the pass.
side wiring harness. If you remove your A/C, you can probably feed the
wires through the remaining holes and wouldn't need to drill. I then
removed all the wiring that was used for the 80 engine. The only wires I
kept (that were in the harness with the CIS wires) were for the oil
pressure system, the cooling after-run system and brake and coolant
reservoir sensors. I had to pull the harness through, separate these
required wires, then re tape them as a small seperate harness. Finally,
install the MC harness in the 80. You need to feed at least the pass. side
harness through, as it is tough to do with easy access. I can't imagine
doing it with an engine in the way. The driver side harness feeds through
the stock hole with no problems.

Install the MC. You should use a hoist...very difficult to steady the I-5
on a floor jack during installation!  Lower it down and slide it onto the
gearbox. Don't tighten the motor mounts yet, as you will need to lift the
engine to fit and install the downpipe. Once the motor is in, you can start
attaching wires exactly as you had labeled them. Swap all parts that the 80
chassis needs like the thermostat cover, special engine/gearbox connector
bushings, engine mounts, etc. The passenger side mount bracket can be left
on, but you must use the driver's side from the 80 motor.

Wire the car. You will need diagrams for both cars. I used a Bentley for
the 80q and a Chilton for the 5k that had Bentley wiring reproductions ($10
at Pep Boys). I didn't find it necessary to remove the 80 dash...just take
out the instrument cluster. Snapping on connectors is the easy and fun
part. Install the coil and wastegate control unit. I slightly modified the
bracket so that these 2 could be mounted together using stock mounting
studs. I used a heavy duty junction box from the 5K to connect my battery
cable to the starter cable. The computer will just fit in the stock
computer mount behind the air conditioner (remove the spring metal clamp
from inside the plastic box and the box will slide right in...like it was
made for it!) I then fabricated some brackets to hold the computer in
place. The difficulty is in connecting MC wires to the 80 fusebox. The good
thing is that the fuseboxes appear identical. One critical connection is
the Black harness plug "B" (schwarz) that plugs into the underside of the
box. I had pulled the same connector from the MC harness intact. I then
removed each wire end from the MC plug and placed it in the 80 plug (after
removing it's matching wire). There are additional wires in the 80 plug, so
you can't just swap plugs. I found the wires were similar, but not exact
color matches. Double check EVERY connection with both diagrams. After that
is connected, another wire goes to the ign. switch (solder/splice) and
another plugs in under the fuel pump. I can't remember the colors, but I
had them clearly marked. Other connections include the temp gauge, tach and
check engine light. These are straight forward. Just determine the color
from the 80 dash, the corresponding color from the MC harness, and splice.
I used solder and shrink wrap, just to be on the safe side. Once
again...double check all connections. You don't want to blow up that
precious computer.

Exhaust. The stock down pipe didn't fit. I cut mine to almost the correct
length to meet up with the 80 cat. I then had it bent toward the center of
the car after the wastegate connection to avoid contact with the sub-frame.
A lot of trial and error. The clearance was so tight that I had to jack the
motor up to get the downpipe in. After getting the correct angle to meet up
with the 80 cat, I welded the flared end of the 5K downpipe on after
placing the floating clamp over the pipe.

Airbox. Either cheap and difficult or expensive and easy. There isn't
enough room to run the stock 5K airbox/rubber airduct and metal intake
tube.  Urq airbox top and air duct are both available...about $400.00 new
for both. I chose difficult and cheap. I took an airbox top from a 4k. I
cut the top section off, rotated it 180 degrees, and glued it back
together. Turning the metering head around gives you the clearance needed,
as it eliminates the metal intake tube. It also gives the added bonus of
shorter intake lengths and less lag. This took some work. I used marine
epoxy and fiberglass to stick it together and make it air tight. I only
used large sections of glass. They must be custom cut for each section of
the box. This is because nothing seems to stick to injection molded plastic
very well. I didn't want a small chunk of glass working it's way through
the intake system. The epoxy sticks pretty well...you really have to pull
on it to separate it. I sandwiched the plastic between epoxy on both sides.
So far it is holding up fine. I plan to keep an eye on this. If I see a
problem, I'll buy an Urq box top. Place the metering head on the airbox
with a new gasket. I used a rubber air duct from a Rabbit. It's a little
smaller, but it fits. I then fabricated a pipe from the Rabbit duct to the
turbo. All the VW guys will recognize the Rabbit duct, and the Audi guys
might snicker, but it works great. The most difficult part was cutting away
sheet metal from the hood latch vert. support pillar. This is needed to
allow the turbo inlet pipe clearance. The hood latch torsion spring gets
sacrificed, but a small coil spring easily takes it's place. I then
re-enforced the support pillar with fiber and epoxy...strong and light.

Fuel lines. Since I turned the metering head around, the fuel distributor
to injector line configuration had to change. I looped mine back around so
that they attach from the direction of the fender. There is plenty of line
length, so you won't kink the lines. The rest is just a matter of finding
the correct size and length line at the junkyard for the application you
need. There are many different CIS cars out there with different
configurations. It took about 3 trips to the junkyards to mix and match
what I needed.

Accelerator linkage. I was able to use the stock cable. I first removed the
head mounted linkage pivot bracket and the 2 link rods attached...No longer
needed. I then fabricated a bracket to hold the 80 cable/sleeve and to
allow ajustability. This is attached to the bracket that supports the
rubber cruise control unit and faces toward the pass. side strut. I then
removed the linkage pivot that bolts to the rear of the intake manifold and
modified it to accept an Audi cable guide end....that's the plastic device
that holds the end of the cable onto the throttle body on the 80. I left
the rod from the manifold pivot to the throttle body intact. Be careful not
to allow the new linkage action to hit the ISV that is bolted next to the
pivot.

Oil Cooler. Tight fit. There is a support tube between the frame and the
pass. side fender. This works well to hang the cooler from. I angled mine
so it fits inside the bumper cover. A cool air duct is then needed between
the cooler and the bumper opening. Holes in the front of the wheel well
help with air flow.

Intercooler. Very tight fit! It will fit behind the grill, but with major
mods. The aux. H2O cooler must go away or be re-located. Next, the hood
latch comes off. I then removed the vert. latch support piece that is spot
welded to the horiz. support. I re-enforced the horiz. piece with fiber and
epoxy. I kept shaving off metal until it no longer contacted the
intercooler. 2 rubber mount brackets need to be fabricated to hold the
intercooler. I bolted 1 on the large lower cross beam under the headlight.
The other bolted to the underside of the horiz. support piece. The grill
needed to have a little plastic shaved off the back to clear the
intercooler. Since I removed the vert. support, the painted trim piece that
fills the gap between the bumper and the headlights needs a new support.
Another bracket connects it to the large lower cross beam. It all barely
fits together, yet looks stock. The last step will be to find a place for a
safety latch. This shouldn't be too difficult.

After-run systems. Easier than I expected. The relay was bad on my 5k
system. So instead of replacing it, I ran my H2O pump off the 80 after-run
system. It has an 8 min. fail safe timer. I wired it from the timer relay
red/white wire. The low speed fan was already pre-wired. I then connected
the original 80 thermoswitch (air activated) wires to the MC after-run
thermoswitch (coolant activated). The injector cooling system was taken
intact from the 5K. Brackets are needed to hold the water pump and the fan.
I mounted the pump to the brake booster bracket. You need to get creative
with the coolant hoses. I used the stock 80 head to rad. hose, cut it in
half and fabricated a T line for the coolant pump. The fan is now bolted to
the head where the accelerator linkage bracket was (the bracket for this
was time consuming to fab. and weld). Test the fan by grounding the wire.
Test the pump by connecting the 2 thermoswitch wires together. (make sure
the ign. had been on recently or it won't work)

Start the car. Should start up almost immediately. If not, pull the codes.
My first try ended with a loud repeating metal on metal sound. That was the
hall ignition pin being bent to a 45 degree angle by the starter over-run
clutch. My mistake. Never would have anticipated it. That's how I learned
that 1/4 inch of flywheel material must be machined! So after pulling the
gearbox and flywheel, machining, re-pinning and re-installing (whew!), the
motor started on the first try. Run up to temp. and the fan should come on.
I had to track down a few annoying problems, but all seems O.K.. The car
feels really strong. I'll be upgrading the boost next, but it is very
enjoyable for now. It really transforms the car.

My project took about 5 months of down time, working every weekend. Much of
that was re-doing things I screwed up the first time. But even knowing what
I know now, it would still take at least 3 months of weekend work. It takes
time to fabricate custom parts, if you care about the final result. It was
a very enjoyable project. I hope my errors will help the next person enjoy
the project even more.

Cost breakdown (approx.):

MC             $1200
T-belt, w-pump etc. $100
Clutch assembly     $350
Flywheel mods       $130
Tie Rod             $110
Mounts              $120
Sub-frame bushings  $120
Control arm bushings     $40
Supplies       $100
               ____
Total               $2270

_____
Dave Close

Oakland, CA
88 Audi 80 Quattro Turbo
74 Lotus Europa Special