Audi UR quattro Rally Build

For a second there I thought you were going with a metric wheel, 15" wheels doesn't seem like a bad solution compared to those. There are a lot of good looking options in that list, I don't think you'll go wrong with whatever you choose.

I love popping over into the classic motorsports section and seeing this thread has been updated.

Adam

Thanks Adam,

You know, you could always "Favorite" the thread ;)

This project is amazing. I've wanted to dothis with a coupe quattro for the last 20 years. You've inspired me to the point where I just might do it!

Bleed242 said:

This project is amazing. I've wanted to dothis with a coupe quattro for the last 20 years. You've inspired me to the point where I just might do it!

If you have one already, do it!  I had thought about converting my 80q, but then decided against it.  I like beating up all the Honda's in the area on the street too much haha.

Installation was relatively simple as we kept all the hardware.



Then we remembered that we also have a broken reflector which we thought would be better used on this car rather than the pristine one that came off it as we are going to be wrapping it anyway a la Rothmans livery:





But how to fix the crack? It can be unsightly but has to be smooth as any hint of a crack will show up through the vinyl film. Fortunately one of our guys has a lot of experience with plastic adhesive and managed a nearly invisible repair.





Now we have to figure out how to wrap the black side pieces. As they have horizontal grooves running along their lengths they won't take vinyl very well. We could try to paint them but it might not match the vinyl and we'd be ruining a set. We have considered filling the grooves with body filler and sanding them flat. That would wrap easily but we'd still be ruining a set. Currently considering making new filler panels. Fortunately we don't have to decide for a while though.

(BULKHEAD)
More rear of the car projects. Another piece (two actually) that would be better stored in the car is the rear bulkhead. It comes in two parts: a lower and an upper. The upper part is essentially a parcel shelf as it is mostly horizontal but is definitely not flat. No parcels will be stored here. We think this will be just a test fit as it may be in and out a lot in the course of the build, though it will be going to paint with it fully installed. It will definitely need to come out to allow us to clean up the aperture edges. Looks like that was cut with a torch.

Both pieces clearly needed to go through the side window openings. The lower panel fell into place without much trouble.



But the upper one fought us hard. We even called the cage builder and the body shop; the last people to mess with it but they couldn't remember how they did it. At least we now had the confidence to know that it does fit so we continued to jiggle it around and look for a way in. This seemed like the way it wanted to go but it wouldn't slide any further back.





Eventually we sort of curved it as we slid it down the cage bars and then it fit nice and snug.







Now we have to get it out again!

(DASH)
Work continues on the dash, bit by bit. We bought an old rally computer that came off a Rothmans car in the middle east. It has no internal parts but we have another one that does and that may find its way into the car eventually. For now this one is easier to install.









Then we thought we'd have some fun.



We just need to repaint one of the 911s and get a Rothmans Quattro model (on order) and we'll have a perfect set!

FUEL TANK
While we seem to be working on the rear of the car we thought we'd throw in the fuel tank. It's big and takes up a lot of space on the parts shelf. What more rationalization do you need. Oh, we also want to see where the fuels lines exit the trunk area so we can figure out where to locate lines, pumps and filters etc.



It was a bit awkward to wrestle into location, but soon cooperated.







The fuel lines protrude through the trunk floor. Perhaps we can extended them through the lower rear bulkhead and mount the fuel pump/s in the cabin.

Acquisitions and (no) Mergers

Another long gap between updates, sorry. We have been traveling and working a lot and then there was the holidays to contend with. Still, we did manage quite a few parts acquisitions but we didn’t get to merge much of them with the car.

Our long awaited 20V engine arrived late last year. Thanks to Marc of EFI Express for assembling it for us. It’s a AAN engine out of an S4 or something like that. Marc tested and resealed it, replaced the head gasket, water pump, timing belt etc. Chipped the ECU, stripped the wiring harness and included an S4 down pipe. Then packed it in this amazing box.







We feel we can have a more reliable 350hp out of this 20V than trying to make the 10V do the same.

We had an oversized grill badge 3D printed by our friend Brandon Horsch.



During our travels we picked up some warning lights and switches from England. We did get to “merge these with the dash.





The dash just needs fuse panels and Dzus fasteners now..

Blower cover from Europe.



We also acquired some works of art from a fellow Audi rally enthusiast in England and couldn’t resist mocking one up.







We have now made it back into the workshop and have been busy refurbishing various parts. Hopefully our next update will be more about mergers than acquisitions. Stay tuned.

Rally Cars Need Heaters Too

We could have just wiped the dust of the heater box a bolted back in place but we are glad we took it apart as we found the heater core had been weeping or leaking. Besides, all the seals needed replacing and it was full of leaves inside.



We had also broken off a tab from the blower while removing it from the heater box so that needed to be glued back together.



The heater box consists of two halves held together by spring clips. It didn't take long to split it.





The leaky heater core and its replacement. These seem to have been used in every Audi, VW and Porsche made in the 80s so finding one was quite easy.





We broke a clip off the heater core lid but have already found a replacement on eBay. We'll pop that on after the dry build.



New seals and into the car with it and the cover we got from a fellow Quattro enthusiast.







It's nice to bolt things to the car. We get all warm and fuzzy inside, plus we'll be warm inside the car too.

We also took the opportunity to refinish our helper springs for the coilovers. Even though these have never been used most of the powder coating had already deteriorated. We decided to try Plasti-dip rather than re powder coating as this is way more flexible and will not crack. We will see how well that works one day in the future.





Wipers, tie rods and heater are next up. Don’t miss it.

DEFROST MANIFOLD

Now we had the heater in we thought it a good idea to install some of the ducting to spread that heat where it might be needed. The foot wells heat comes right out of the side of the heater box so we don’t have to deal with that, and the center and side vents are fed from flexible pipes so we can figure those out later. But the windshield defrost blows through the firewall bulkhead and into a distribution manifold that used to be part of the molded dash pad. Fortunately we hadn’t managed to throw the dash pad away.

This is the plastic distribution manifold on the underside of the dash pad.



From what we gleaned looking at hundreds of restoration pictures is that you cut the dash pad to leave just this front area containing the manifold and vents then remove all the molded on dash pad foam from the top and bolt it back into place. Of course our manifold was cracked so we had to disassemble the thing.





This is how the manifold interfaces with the bulkhead/dash tube once it’s all put back together. You can see the central feed from the heater box below the dash tube. 



Next we removed the excess dash pad material with a cutoff wheel and set about cleaning it up.







We covered up some excess holes that were previously blocked and painted it and the vents satin black.

Then we set about fixing the plastic manifold.



While the glue was setting up we riveted the vents back into place.





Then we applied some sealant before riveting the two parts back together.





And then popped it into place.





For some reason this was one of the most satisfying projects we have tackled so far. Next time we’ll restore and install the washer bottle and coolant reservoir. Maybe not so satisfying.

Cracking on with engine bay stuff we installed the clutch master cylinder. Remember, we have an 20V AAN engine just itching to try on this engine bay for size so we want to get as much engine bay stuff figured out before it crawls in there.



Not wanting to lose our bottle before the engine fit we also tested and installed the coolant reservoir. We rigged up this pressure test to see if it would hold 1.35 bar:





The reservoir didn’t leak but the cap let go at about 1.2 bar. We tried our cap from the 85 URQ and it held. We are going to need a new cap.



We cleaned it as best as we could and bolted it in place along with the washer bottle.



We should’ve thought about this earlier but after crawling under the front bumper all afternoon we decide it was time to take the front bumper and bumper bar off the car. Duh!





We now have a walk-in Quattro.





We know, not very exciting stuff but next we are going to work on the very trick twin master brake system with bias bar that we got from England! Riveting stuff! No, actually it bolts in.

BRAKE MASTER CYLINDERS 

We decided some time back that this car would dispense with the hydraulically powered brakes and employ dual master cylinders with a bias bar adjuster but were never quite sure how we'd accomplish that. Then a friend turned us on to Compbrake in England who have a bolt-in kit for the Quattro. How could we say "no"? 

So we ordered one up and it arrived in just a few days. Seems to be very comprehensive. It even has a bracket and lines for remote reservoirs. 

 

 

The first job was to figure out how to mate up its four bolts with three on the bulkhead. It was seemingly not as "bolt-in" as we'd hoped. We made a template and transferred it to the car and immediately discovered that the four required holes would interfere with the pedal mounts. Something did not seem quite right. 

 

 

 

Then a gentleman and fellow Quattro rally car builder called Frank pointed out that the kit is designed to bolt to the OE brake booster not the firewall. He also highlighted how far into the engine bay this would make the assembly protrude because he had installed one himself. However, he had engineered a solution by way of an interface ring that was only about an inch thick rather than the 5"-6" of the booster. A few more emails and some PayPal and one showed up at our shop. 

 

This made all the difference and we were able to mock it all up in short order: 

 

 

 

We then set about making it look nice by trimming it and painting it: 

 

 

 

 

Frank also included some DOM tubing to replace the 5/16" threaded rod that came with the kit as this linkage was going to end up quite long. The DOM would be much stiffer and didn't take much work to cut it to the correct length, thread it and attach a couple of short, threaded rods to each end. We will probably have this assembly plated before the too long. 

 

 

And here it all is installed. We attached the reservoirs directly to the cylinders for now as we don't yet know where everything else is going. The Group B cars had them mounted to the strut bar but we are not that particular. We'll see what seems the best location later in the build. 

 

 

 

Next on the list is engine prep. Look out for that one soon.

Those reservoirs... Do you think they are supported well enough, especailly in a car that could experience a lot of vibration and bouncing around?

Love your series.  By all means continue. 

Stu

stu67tiger said:

Those reservoirs... Do you think they are supported well enough, especailly in a car that could experience a lot of vibration and bouncing around?

Love your series.  By all means continue. 

Stu

Good point Stu. We haven't committed to them being there yet.

ENGINE Teardown 

Well, this is a big step forward for the project. It’s time to take the engine off its pallet and get it into the car. Of course it is not that simple. We have lots of ways to make it complicated. 

 

As we’ve previously discussed, we decided to go with a fairly stock later AAN 20 valve engine rather than try to wring extra power from the original 10 valve that came with the car. We should be able to see 300hp from this without creating a stressed out monster nor breaking the bank. Purists may scoff but they aren’t paying the bills. 

We sourced this one from Marc over at EFI Express. They are huge Audi fans and know a lot about these engines. This is a tested and resealed, good engine, basically ready to bolt in. Marc chipped the ECU and stripped the harness of all unnecessary body wiring. 

However, our aesthetic bar has been raised somewhat over the course of the build so now we feel we need to strip it down externally and clean, paint a re-plate every last nut and washer. We will try to restrain ourselves however. It’s just an engine and this is supposed to be a rally car. Let’s see how this goes. 

First step was to get the thing in the air and on to our engine stand but before we could do that we wanted to remove the clutch and flywheel. This revealed a new crankshaft seal as expected but a bonus stage 3 CenterForce clutch that looked like it might even be serviceable. Thanks Marc. 

 

 

 

 

We were always going to have to replace or modify the intake manifold as the stock location of the throttle body will interfere with our side mounted radiator, so we started dismantling the intake side of the engine first. Getting at the ten Allen bolts that held it on was a big PITA. It would have been easier if we’d realised there are access holes going through the manifold before we started rather than after we’d finished DOH! 

 

 

 

 

We also needed to delete the AC compressor so the belt and all the ancillaries came off. 

 

 

 

Unfortunately we decided the idler and belt tensioner pulley bearings were both near the end of their useful life so we’ll add those to the list of refurbishments. 

We also discovered our engine came without the front engine mount; the one that stops it moving up and down when you get on the gas, so we’ll have to source or make one of these. 

 

We are also going to need some different senders and sensors to drive our non-stock VDO gauges. At least they’ll be clean and shiny. 

 

We believe the turbo is good and are reluctant to open up this rabbit hole so we think we will just clean up the exhaust side in situ. Let’s see how that goes. 

 

 

So check back later to see if we manage to not replace, repaint or re-plate every last piece of this engine. 

 

SIGNATURE 

WHEELS

Halfway through our engine tear down our new wheels showed up. Yes, they did distract us.



We chose these from BRAID’s catalogue because they look very similar to the BBS wheels the Rothmans (and some others) rally Quattros ran back in the day. Look:



Specs are:
- BRAID Serie 4 RC
- 15x10
- Et0
- 5x112
- 57.1 center bore

As far as our research suggests, the same as the originals.

Of course we took lots of pictures.











Then, we installed a couple of our TB5 tires to make sure the wheel and tire package would actually work.









Nailed it!



In case you weren’t paying attention earlier these tires are Michelin TB5 historic tarmac rally tires in size 265/40-15 and are just 23.3” overall diameter. Again, the same size these cars ran in period, at least in tarmac trim.

Next week back to the engine, we promise.

We promised you an engine-based post this week so here you are.

As we mentioned in an earlier post we were supposed to just bolt this in but have recently gotten carried away with cleaning and polishing everything on this car so let's see how nuts we can go with an engine. Is there therapy available for this stuff? We need help.

So we started by painting the block, even though nobody will ever see it once it's in the car. It's not like it didn't have paint on before. Jeez!



Then we turned our attention to refurbishing the cluster of accessories we previously took off.

We decided to reduce the size of the AC and alternator bracket as we are deleting the AC. We could have just found a non-AC bracket but they were expemsive and all in Europe because Americans can't drive without the windows up (electric) and the AC on.



We couldn't make ours quite the same shape but we did cut a sizable chunk off the rear:





The idler pulley bearing was noisy and NLA so we just replaced the pulley with a GM something or other.



About the same size but has the bearing in the pulley like a normal one not inside the bracket like an Audi one. Consequently some re-engineering was required.





It turned out pretty nice, if that's not a pun.



We also blasted and painted the engine mount brackets because, well, we're sick. Next week we'l probably paint something else; maybe gold! Stay tuned.

ENGINE REFURB 2 

We know, engine stuff. (Focus TIM). But look what arrived this week! 

 

We could have just tried to convince you that we had a surge of enthusiasm and finished the car but that wouldn't be right. 

We did paint something though, as promised: 

 

Gold too! 

 

and red! 

 

We also had a go at cleaning up the oil pan. It's not obvious in the pictures but it did make quite a bit of difference. 

 
 
 

Enough that we think we might want to have another go at the transmission case with this stuff. 

The last thing we worked on this week is only peripherally related to the engine but, as we were about to send a load of parts to the platers we wanted to include the power steering lines fittings. This is the 83 URQ's lines and oil tank along with the AAN's pump. The gap on the lower run is where the accumulator would go for the power brakes but as we are not using power brakes we can dispense with that. That means we need to come up with one continuous high pressure line and also some fittings for the pump end. 

 

We sourced a high pressure line from a servo boosted car as it's fitting routes better around the steering rack because it does not have to go first to the accumulator. Then we cut out all the fittings and sand blasted them ready for plating. 

 
 
 

Quattro Rally Project - Hot Side Engine Refurb

This week we turned our attention to the hot side of the engine and removed the turbo, exhaust manifold and waste gate. The turbo will be sent out to be refurbished, the exhaust manifold will be replaced with a slightly better one and the waste gate will be, well, we are not sure. We know we are not keen on the red cover however.





This is the eBay special $85 exhaust manifold we got. If nothing else it doesn't need sand blasting! When the turbo comes back we will have to decide whether and how to refinish it.





Inspired by our gold coil cover we finished the rest of the valve cover. We know, it's a bit flash but it is rather reminiscent of the Group B 10 valve engines so we feel good about it.





Then we got distracted again and made a fake license plate. It's the little things...

Turbo Trouble & Fuse Dash Panel

We received some bad news from our turbo shop, G-Pop Shop this week. Our turbo is bad. Exhaust turbine ate something that didn’t agree with it.





We got on the blower to our engine supplier, EFI Express and they soon had another core sent out. This one turned out to be fine. The other good news is that the bad turbo was never on our engine, it was just one of many EFI Express had on the shelf so whatever did the damage almost certainly did not pass through our engine. PHEW. Can’t wait to get the refurbished turbo back now.

While that was all playing out we reassembled our belt tensioner. These are NLA and ours had a bad bearing. We sourced and new bearing but had to make our own rivets to put the pulley back together around it, followed by a lick of paint of course.



We also continued to work on our dash mounted fuse panel design. The original works cars had three fuse blocks holding ceramic fuses mounted through the center removable panel. We want to use three similarly sized panels but with more modern blade fuses. You’d think that would be quite simple but it’s proving quite difficult. We can find side entry versions but our wires have to come in from the rear.

Group B fuse blocks:



The collection of candidates we have assembled so far:



The one on the bottom right would be perfect if it held 12 fuses instead of 8. You’d think that were available wouldn’t you. Nope. We may have to compromise.

Now we have the wheels on the car the only thing stopping us putting it on the ground was the lack of springs. That and a good reason to actually do so. Undaunted we installed the springs.

Quattro Rally Build - More Engine Bay Work

More distraction this week but look at it! Wouldn't you be distracted?



Some of this is for the engine refurb but some has been holding up some ancillary stuff so we got busy. We installed the wipers (can you spot the long awaited plated parts?)





This piece of automotive jewelry holds the blower motor resistor!



Alternator fan (that's engine related)



Power steering rack fittings.



and the front left tie rod adjusters.





We even got our anti-roll bar clamps back.





So we got to cross a ton of stuff off the list; all be it, little stuff. Still, it's all progress, right? Got to keep moving forward.

It's Time to Get Serious - Cold Side Engine Reassembly

This week we started on the serious reassembly of the engine. We’ll try not to get distracted. We started on the intake side as that has the most shiny bits ready to go. First up the modified alternator mount:



Then the coolant adapter. We were advised to get a straight one in metal for better fitment:



Then we installed the alternator, power steering pump and belt tensioner:





We still need to find a shorter accessory belt but that’s not what’s stopping us completing the intake side of the engine; we need an intake manifold solution. Because the radiator on the UR Quattro sits the side of the engine, the AAN throttle body would interfere with it because that is located on the center of the AAN intake plenum:



We either need to modify our stock one or source an aftermarket version with the throttle body on the front. We favor the aftermarket options from BST, Wagner or whoever else sells one. Unfortunately finding one is proving troublesome as they are basically NLA. Let’s see what we come up with.

Hey, look, we didn’t get distracted. Next week’s topic will depend on what shows up first: a refurbished turbo or a cool intake manifold.

Refurbished Turbo - Hot Side Engine Reassembly

The turbo won. Turns out it takes longer to find a unicorn aftermarket intake manifold than it does to refurbish a turbo. Well it does if you are a professional outfit like G-Pop Shop https://gpopshop.com/







So we’re going to assemble the exhaust side next. First we’ll need a heat shield:



Our new exhaust manifold fit well but we did have to shorten some studs to get the nuts on.



The rest was easy bolt on stuff. New gaskets of course.







And we think we’ve found an intake manifold. Subscribe if you want to find out what kind.

Didn't want to use an RS2 exhaust manifold?  Did you have the turbo rebuilt to RS2 specs?

Solving Intake Manifold Challenges

We found an intake manifold!



It’s a new old stock from Wagner Tuning. A fellow Audi nut had it in his stash and no longer had plans for it. We do! This thing should be plug and play and make moving forward very easy. We test fitted it with the 034 Motorsport phenolic spacer kit and it fit perfectly! Trouble is, nothing else would fit to it. Firstly, the throttle body and power steering pump now want to occupy the same space:





And the fuel rail won’t fit and has nothing to bolt to. At least the injectors line up with the injector holes and there are no inserts to source.





Time to get creative……….

Solutions for our beautiful intake manifold

Last time we conversed we were reveling on the beauty of our aftermarket intake manifold and despairing at the frustration that nothing would fit around it. Now we think we have solved all these issues. Read on:

First we made a throttle body adapter to place the throttle body above the power steering pump:

Then we started to hack up the OE fuel rail. We stripped off all the brackets and fuel lines to verify that we could use it. The injector holes lined up and the rail snuggled up nicely against the intake runners.



Then we created fuel lines and incorporated an aftermarket fuel pressure regulator, a fuel pressure gauge and even a fuel sampling port!









And somehow during this process the manifold itself got painted gold to match the valve cover.

We also came up with a way to secure the now floppy dip stick tube.



We feel quite good about solving these problems. Of course there are a few minor details to work out such as the throttle cable angle of attack and mounting of ancillary items but they should be easy to figure out. At least now we feel it is time to introduce the engine to it’s new home so they can get acquainted. We do need to run brake lines and a few other bits and bobs around the engine bay before we bolt it in but it’s nice to have the engine out of the workshop.