The Project Pad

I swapped turbos the other day as part of a methodical process to address a pattern of poor and inconsistent acceleration characteristics. The AAZ based K14 turbo I've been using for the past year and a half is just not working well. I would guess the waste gate isn't sealing, is stuck or something else. The replacement turbo is also a K14 but it's from a VW EcoDiesel which has a different CHRA, smaller comp wheel and stock WG set for 8psi. They look virtually identical but have few common parts. This "new" (from 1992) turbo has 20k original miles and is in perfect condition. The car now pulls strong up to 15psi with a boost valve and has more importantly, a much smoother power delivery. I used this turbo when I first put the car on the road and switched to the bigger 1.9 AAZ K14 when the engine was broken in. It's possible the old turbo never ran correctly the whole time. The waste gate function cannot be observed unless disassembled. I think eventually I will switch to a more modern WG turbo like a GT2052. I swear if I didn't have this car to tinker with I don't know what I'd do; stable cold fusion maybe. I changed the oil today @ 8mos & 4800 miles using Rotella T6. The odometer says 189,500 now, 23,000 since swap.

Cool glad to hear.

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I'm still trying to break 50mpg. I've been exploring the range of pump timing and narrowing it down. Running up through the gears testing acceleration works against good mileage though. The way to get the best #'s is to stay out of boost and maintain minimal throttle lever position. It's harder in the colder months to get good accurate data. The pump timing is now @ .85mm; it starts and runs smoothly. I bought and installed a programmable wiper relay last week. It came stock in many VWs and Audis just none I've ever owned. It works great.

Go 50-55mph

chaloux wrote:Go 50-55mph

That is what I need to do. After the first 49.1mpg tank I tried to improve on it with timing changes but I neglected to record the baseline timing. My driving habits have been too varied lately for consistent data. I've defined the upper and lower range of timing by moving the pump in .05mm and/or .1mm increments and checking mileage and perceived acceleration. If I have to blow the tires up to 60lbs and duct tape cardboard over the wheel wells this is car getting to 50mpg. :-)

Is that relay 99 you're talking about?

PRY4SNO wrote:Is that relay 99 you're talking about?

Yes. That's the one I have. There's 2 relays available out there; the 99 is NLA except used. The newer one uses the washer switch to set; old one uses intermittent/off.
http://www.audiworld.com/forums/audi-90 ... d-2123066/

99 is much better IMHO.. have had both and prefer 99 hands down.

The last tank was 47.5mpg during the last coldest weather. The timing is now set to .92mm. The mileage seems to decrease above and below this setting. It runs and drives well with no issues. This car has the best heat of any car I've owned. I removed the A/C evaporator when I changed the heater core and put new foam on the blend doors.

awesome rich. I have been daily driving an 03 ahu jetta and it had demotivated me from working on my 90 because the stock TDI was so damn slow!!
I just put a 2.5" straight pipe, 520 injectors and a malone stage 3 tune in it with EGR removed. Now I am motivated again. Its not fast but it has a nice gob of torque I can see being very fun in a quattro.
That is seriously impressive mileage for the winter. I cant get my mk4 over 38 in the winter.

I've had a starting problem recently. It turns out my 30 year old glow plug relay wasn't glowing long enough and had a pitted contact inside. This car has always started well at 0º and I was surprised and concerned when it didn't. I put in a BN relay I've had in the glove box for 2 years as a spare. It has a distinctly longer glow when it's cold, up to 20 seconds. It now fires up like always. I improved the GP wiring, eliminating the fuses and used better connectors. I swapped a tire plug for a sliver of steel in my left rear tire during a snow storm last week. It's tolerable if you have everything you need with you; compressor, jack, plug kit.

Solid update!

Three things finished this weekend. First was installing Weatherguard side window deflectors. The instructions were a little vague but they installed easily. One major beef I've had with these cars is that rain/snow pours in with the window opened a crack while driving or sitting. Next up was to change the 2 year old and 20k miles fuel filter. I drained a few cc's from the bottom and it was cloudy with wax pieces floating on top. There was no solid water globules; more of an emulsion/cloudiness. I use a spin-on Baldwin filter BF7772 @ 2 microns. The steering damper was last; delivered by FedEx @ 6:30 pm yesterday right to my door; a new Mercedes part # 1244630432 from GAP. They had a choice of 2 dampers; one made by Febi/Bilstein and the other Stabilus. I chose the Stabilus because it was $10 more and looked more well made. It took 5 minutes to replace with the battery removed and fit exactly as the old one. I reinstalled the previously mentioned GP relay after I filed, polished and cleaned the pitted contacts inside. Time to start cleaning it up to prepare for the trip to Carlisle.

The mileage is creeping back up; 47.7 last tank. This current tank is 520 miles still touching the half tank mark. This might be the record breaker. I raised the boost to 15 psi, set the pump timing to .945mm, changed the LDA boost diaphragm adjustments to decrease and delay fueling onset slightly. I finished my afterglow timer circuit last month and it works exactly as planned. I used a 5 minute mechanical timer switch, a large terminal 50 amp relay from an ABS pump, and a lighted rocker switch. I have an LED wired to the glow plug harness so I now know when the plugs are actually on. There's 2 other switches wired to relays for the coolant glow plugs for quick heat and warm-up in the very cold weather (like last winter). I'm leaving for Carlisle in the AM for the first long trip in the "oil_can" over 100 miles. See you all there.

Such an awesome build! A true inspiration! Well done.

deaner wrote:Such an awesome build! A true inspiration! Well done.

Thanks, the comments and support from you and everyone else who posts on this thread continues to inspire me and makes it all worth it.

I fueled up near my home on the way to Carlisle, I got the best fuel mileage ever (EVAR!) in this car, 11.8 gal for 593 miles = 50.3mpg. I now understand I must have set the pump timing to .95mm back in September to achieve that 49.1 mpg I recorded. The car ran beautifully for the 580 mile round trip. No smokiness, no temp issues, cruise control at 75mph, boost at a steady 12psi up those hills in PA without effort. I pushed the car hard at times going 80+ but the RR wheel is bent slightly so no faster. The car seems a little smoother and subtly quieter after the trip. I know I blew the stink off it. I had a great time meeting the Audi contingent at Carlisle. I will return again for sure. The first time is overwhelming in the best way. It was amazing to hear the love for these cars coming from actual voices. You are all cool, excellent people.
Rich

Good to actually meet and talk with you Rich! That's great mileage!

It was great to meet you Rich. Glad you made the trip, hopefully we will see you next year too!

2nd...awesome to finally meet you and see the car. Really good work!

I warped my rotor(s) in a panic stop this am. I declined the offer of a 15 lb turkey as a hood ornament. It appeared as the wipers were cleaning off quickly forming condensation on the windshield while negotiating a steep downhill. I locked hard and left tire marks on the road. Probably left some turkey crap as well judging from its rapid departure from the scene. The brake pedal now throbs up and down like an ABS pump, making the car undriveable really. These were new pads & rotors last year and have less than 10k on them. I am aware that I did not bed my brakes in properly initially from what I am now reading. I tend to drive with minimal braking which is part of this problem. This has never happened to me in all my years of driving. I'm going to replace the right caliper to match the rebuild on the left as one of the pistons is sticky/stiff. Is it worth getting the rotors cut slightly or are they done? Do I now need pads & rotors? Any helpful info or suggestions is welcome. I'm going out to pull it apart now. Once I get the wheel off that is stuck.

Have the rotors turned... the "warping" you speak of is a pad deposit. You'll find out at that time if it's too much to reuse your rotors. In theory you should be able to use your old pads and re-bed everything but you'll want to measure them first.

PRY4SNO wrote:Have the rotors turned... the "warping" you speak of is a pad deposit. You'll find out at that time if it's too much to reuse your rotors. In theory you should be able to use your old pads and re-bed everything but you'll want to measure them first.

Thank you for the reply. I've decided to get new rotors, a rebuilt right caliper to match the left and chalk it up to experience. I was so obsessed with the mileage I wasn't thinking about the brakes. This is the first car I've owned with 2 piston calipers capable of stopping more quickly than I'm used to. I was pretty unaware of the importance of bedding brakes and the actual process that takes place.
http://www.stoptech.com/technical-suppo ... ther-myths
http://www.stoptech.com/technical-suppo ... tem-bed-in

That's the exact white paper I was basing my comments off

I tend NOT to drive like it's stolen; I drive like I want my car to last a long time. Driving with kids, dogs, shi**y roads and LEOs also have a way of making one more of an adult driver. I got the stuck wheel off with PB Blaster and a new dead blow hammer. I'd been running without wheel covers through the winter and there was more corrosion than I expected on the hub. Unplanned car repairs are a great excuse for buying new tools.