Audi Quattro Turbo Diesel Build - Now with video!

[rabbid79]

Got the car running a few nights ago.  After priming and a new battery, it started right up.  I must say, the sound of diesel emanating from this thing is so strange.  Put the front end together and drove it for the first time today.  I've put about 25 miles on it since.  I was going to head out for a celebratory shake (milk, not diesel ) this evening, but when I went out to the garage, I was greeted by a rather large puddle of coolant under the right-hand side of the car.  I think my block heater came partially out.  It's the only thing on that side of the engine that could leak coolant.  There aren't any other coolant lines on that side.  With a flashlight, it looks like the block heater is crooked.  I have had the engine up to operating temperature a couple of times before, but this was the first time I parked it in the garage with the hood closed after driving.  I think I'll have to remove the down pipe to fix it, but that shouldn't be any big deal.

Giles was right, this pump puts out a lot of fuel.  I need more boost to clean things up.  The smoke isn't bad as long as I keep my foot out of it.  The turbo makes a beautiful whistling sound pretty much all the time.  Before I touch the boost I need to break it in and get the boost gauge/pyrometer installed.

The clutch is a little bit grabby, but not bad.  I like the positive engagement.  I took some measurements of the ride height before and after the engine swap.  It rides about 5mm lower in the front with the heavier diesel engine.

I can't really comment on the power since it's not broken-in and I'm at stock boost (~10 PSI) with no intercooler.  But I can tell you it's a hell of a lot quicker than the gas engine that was in it previously.

I'll try to get a video of it running in the next couple of days.


Needed to make a spacer to keep the over-run clutch on the starter from hitting the back side of the flywheel.  You can also see the wires from the EGT thermocouple waiting to be connect to a pyrometer:



Custom crank case breather hose, air filter, and heat insulation for the large battery wire:



Custom glow plug relay installation:



I was able to get some new Hellas for a good price, so I installed them at the same time I put the front end back together:

[TPW]

Why is there no intercooler?

[rabbid79]

Why is there no intercooler?

The intercooler is "phase 2", along with the tachometer, cold-start advance, gauges, etc.  I just wanted to get it to the point where I could start driving it on a daily basis.  I don't have all of the parts I need for the intercooler installation yet.

[lord_verminaard]

Looks amazing.  You are definitely doing this right.  Can't wait to hear what it feels like at 20 psi intercooled.    Might make me rethink my engine swap in my CQ. 

Good work and I look forward to the updates.

Brendan

[rabbid79]

Thanks for the compliments.

It was indeed the block heater that popped partially out.  A word of advice for whoever installs a block heater:  Make sure to pull on it to make sure it's snug.  Don't just go off of how much torque you put to the tightening screw.

One of the next orders of business will be to bypass the cruise control vacuum pump to run the HVAC controls.  The Bentley mentions a way to jumper the connector for testing purposes so that the pump always runs.  It's just a matter of making sure that it doesn't always run, and only runs with key turned to "On".

[vwjunkie53]

Nice build! Maybe I missed it, but what size head did Giles use for your pump?  11 or 12 mm?

Jason

[rabbid79]

Hi Jason, I honestly don't know.  As far as I know it's the same 10mm head as before.  He said it's good for 250 HP at 30 lbs of boost, that's all I know.  I assume that means the boost pin and spring are set up to linearly deliver fuel up to that much pressure.

[rabbid79]

A few updates:
I have a little over 3000 miles on the engine now, and it runs pretty well.  I think there's a slight miss at part throttle, but maybe I'm just being overly sensitive.

I did a couple of cold start tests just to see how it would perform.  We had an 8*F morning last month.  I left the car out overnight the night before just to make sure it was cold-soaked.  I cycled the plugs twice and it started right up.  Granted, it missed for the first 20-30 seconds, but was fine after that.  It also gets up to operating temperature regardless of the outside temp.

I've had two oil leaks since the swap.  One was from the VC gasket because it wasn't torqued down tight enough, and the other was from a leaky o-ring on the tube that connects to the intake manifold.  The specific o-ring from Audi was NLA, and I couldn't find a suitable replacement, so I remedied the problem by sanding down the area on the tube that has the o-ring seat, and just installed a throttle body gasket from a turbo-gas car.

I've only completed two fuel economy tests, and am working on a third one right now.  The first one averaged 31.75 MPG w/ stock all-season tires and conservative driving.  The second one was 30.25 MPG w/ more spirited driving (Quattro + Snow = Fun).  I changed a few things before the third test.  I set the air pressure in the tires to 44 PSI, disconnected the LDA, turned the fuel screw 3/4 turn CCW, added Diesel Service to the tank, fixed the intake manifold/boost leak, and am keeping the car plugged in more at night.  I get more than 600 miles out of a tank so it takes a while to compete one of these test, but so far it's looking good.  When all is said and done, I think I'll be up 1-2 MPG over my first test.

I'll be glad when this test is done so I can reconnect the LDA and get some power back.  Before I turned out the fuel screw, I was getting a lot of black smoke at medium-to-full throttle at low RPMs.  It's just a light haze now.  I do miss being able to smoke-screen jerks who are tail gating me though.

Messy intake manifold from boost/oil leak.


Modified intake pipe.  This won't be around for long though.  Intercooler install in progress...


A couple of before and after engine swap shots.  I really love the simplicity that comes from swapping from gas to diesel.

[rabbitman]

Man that diesel looks way better!!

Good job

[rabbid79]

Man that diesel looks way better!!

Good job

Thanks.  Latest fuel economy numbers are in:  32.6 MPG.  Not as high as I had hoped, but considering this is 100% city driving in a 3400 lb. AWD car with less than ideal gearing, I guess it's ok.  I may try one more fuel economy test (i.e. intentionally keeping my foot out of it) in a couple of months once the weather warms up a bit and I have the intercooler installed.  I need to do it while I still have these skinny all-seasons on.  Once the wide/heavy summer tires are on, it will be too late.

Speaking of intercoolers, here's the NOS one I purchased recently.  The core is 7 x 13.25 x 3.5.  I also bought a silicone "michelin man" hose.  The factory rubber hoses don't last long, esp. at higher than stock boost.  I just need a couple more parts and then it should be pretty much a bolt-on affiar.

These factory intercoolers have a reputation for blowing off the crimped end tanks at high pressure.  I've even had it happen to me once.  I was running about 16 lbs. of boost on an '86 5KTQ and blew the tanks off during a 1-2 shift.  The Audi 5000s didn't have pop-off valves, so there was nowhere else for the pressure to go once the throttle body slammed shut.  I don't think I'll have a problem running this at 20 lbs. on a diesel.  I actually have a used spare intercooler that I may test my theory with initially...  just in case.

[TDIMeister]

Sweet project, such a clean and well-cared for car!  It looks like it's in better shape than my `94 S4! 

[dankcorey22]

You got any videos of it running yet? I and everyone else would love to see it 

[rabbid79]

Thanks guys.  No video yet.  I'd like to wait until I have the tachometer working and the intercooler, boost gauge, and EGT gauge installed.  Then I'd like to have it dyno'd up in Salt Lake where there's a 4-wheel dyno.  Probably get a video of it then.

[zagarus]

Sooooooo clean!  The detail you've put into this build is amazing keep up the good work!

[macka]

One word, Sexy