The Project Pad

Nice work on the pedal, I would have left the oem and put the potentiomèter somewhere in the bay (driven by cable)

This project is so odd, I love it

LeafBox wrote:This project is so odd, I love it

thanks!

I dont find it too odd that someone who drives 700 miles a week in very bad conditions would want a quick, fuel efficient all wheel drive classic audi, but thats just me.

Foscora wrote:Nice work on the pedal, I would have left the oem and put the potentiomèter somewhere in the bay (driven by cable)

I spent a long time trying to do that, the feel was terrible. I built several different cams for the pot, but it still wasnt right. Mk4 pedal is a MUCH better solution.

Okay, good to know

This weekend I finished the wiring harness and put the dash in and took her on her first test drive. Still have LOTS of loose ends to tie up, but I can say that this car is going to be awesome.

I love this little holset, it spools right up, I really only drove about 5 miles, so didn't get a great feel for when it spools, but it is not laggy feeling at all. Its snotty and seems like it wants to pull hard in the mid and top, but I was pussyfooting around big time watching temps etc.

I did a couple very mild rips through first and second and I swear it feels like a chipped 20vt, its pretty damn awesome. Honestly the amount of power and the delivery is WAY better than I thought it would be.

Now for the not-so-good news, once I got about 4 miles on it, it started to run "funny". Tipping into the throttle would make it buck, pop, and smoke for a second then it would run alright. This happened every time I tipped into the throttle when going down a mild hill. I drove her home and brought it in the shop, where I realized that I wasnt able to check the timing with VAGCOM like I normally do. The "tdi timing" button does not appear.

To me it acted like the injection timing was VERY retarded, but the strange thing is it ran just fine at first (coolant temps around 155 when I started the drive, got up to maybe 165 while driving). Once I got it home, it stumbled hard whenever given throttle and started hard too. Not sure if fuel temp increased and retarded the timing, and thus the overall timing go retarded enough to run funny? It has always started right up instantly, but this is the first time I have ever really gotten any heat into it too.

Warning, boring diesel rambling ahead:

Too many variables to know yet. Compression still checks out well, mechanical timing of the belt cam and pump look right. Tonight I will retorque my head studs, reset timing mechanically and see if I can get the timing right with VAGCOM. I did some googling, and apaprently some tunes on the old TDI's will cause that timing button to go away. Apparently field two here is the timing, and it goes between 0 and 100, 50 being the factory setpoint. Mine says "003" here, so maybe its just WICKED RETADED. It did run like total ass when I hit "switch to basic settings".


Once I get this figured out, the car is going to be awesome and actually haul ass for what it is. I love the feel of the suspension and the light little 4 cylinder with a snotty attitude. I just hope I don't have a more serious problem like injection pump or injector probs.

Its hard to imagine it would start and run so well when mostly warmed up, and then go to shit when giving a bit of driving, but maybe.
Here is a quick vid of it when I first got back from the drive. You can hear it sort of pop and fart when revved. This is not how it has run in the past, but again, its never been warmed up fully. Its also very smokey, but my first tune is not scaled at all for boost, so its just 100% fueling based on throttle, so smoke is expected. It actually did not smoke at all when driving normally until the bad running started.
[youtube]https://www.youtube.com/watch?v=8jTfbV8WSdI[/youtube]

Dana,
I'm really excited to see the final product on this and see hear how it drives. I think a C4 100 Avant TDI swap may be in my future!

Though on the topic of your stumbling, have you checked for air leaks in your fuel system? I've had issues like this before that came from air leaking into my fuel lines, even if there's no visible fuel leaking out. Diesel fuel systems hate air...

Yea man, I am excited too. I was AMPED when I took my test drive. Like seriously really amped. I don't know what I was expecting, but I swear the thing is more responsive than my ALH car that has a tiny vnt15. Probably this is due to a much more aggressive fueling tune, but I was still amped. The power and response from the turbo were really looking hopeful. The running issue kind of took the wind out of my sails.

I reset all the timing today and checked it again, and I was able to get it to run decent and get a decent and steady timing number with the pump all the way advanced. My theory is that the timing mark on the flywheel in relation to the bellhousing might not be exactly right. The flywheel is from and audi 80, trans from a b5 a4 TDI, and the engine from a 98 jetta. I am going to try and re-time it with the crankshaft set back one tooth and see if I can get the timing dialed in. Currently its decent, but I would like a little more advance, and cannot get it. One tooth should put me right in the middle of the range so I can play with the timing some.

Dana do the hammer mod, don't mess with your static timing.

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scubagli wrote:Dana do the hammer mod, don't mess with your static timing.

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I'm not sure I follow. I thought the hammer mod referred to tapping the top cover one way or another to change the middle range of the quantity adjuster. My IQ is nice and solid at 3.6, so I dont think I need to adjust my IQ.

What I am trying to do is to set the injection timing like you would do after a timing belt.

Hammer mod is as you described Dana. Perhaps he means advancing timing in adaptation. However, you should be perfectly mechanically timed before doing that. It gives you a nice torque/economy bump by advancing the injection timing electrically. I did it on my ALH, makes it sound like a tractor. Can't do it on PD engines.

I swear, the 4 cylinder TDI in my S6 felt like a very strong stock AAN in the same chassis. When I had 5 guys in the car they couldn't really believe that it was so "fast" -especially with 5 guys in the car! My reasons were exactly the same as yours for doing the swap. And I would also like to note that I liked the way the 4 cylinder drove a lot better than the 5 TDI. It was just more torquey, probably due to the vnt.

I did the same thing with the mk4 pedal. It was actually very easy and I was also not looking forward to it lol. And it worked perfectly.

In retrospect I should have just fixed it. Oh well.

Yup sorry brain fart. Don't mind me.[SLEEPY FACE]

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I am going to try and verify real crankshaft TDC with the protruding end of my calipers through the #1 injection hole.

I have always verified TDC by just "feeling it out" with a screwdriver in hand. I can get it very close that way, this is how i originally verified the flywheel marks on this engine. There is a window of movement of the crank that I cannot detect with just my hands and will have to use something more precise.

My gut is that I could just advance the pump by one tooth and readjust using VAGCOM, but I would love to find that my method of finding flywheel TDC was slightly off. We shall see.

Maybe my pump is just really worn and needs to be fully advanced to get into the bottom of the spec. Certainly possible, but it gives no other warning signs of being bad. The shaft and nice and tight and it runs very quiet.

I'll know more tonight. I want to drive this again, i was super fun. I was giddy like a schoolgirl until i realized it was running WICKED RETAAADED.

always a good read Dana, i think i may try to do this into a a6 wagon if i can find one. but im thinking of trying to go full MTDI, simple throttle cable and mimimal wiring/no computer. I have not done much research yet but that is my idea.

the mtdi vs etdi is an endless debate. Its all personal preference. I will say that making a TDI run is very simple. It just about the same as making a 20vt audi run. Basically a couple power wires and a few outputs to the cluster. The most complicated thing was cruise control wiring and pedal switches, and that was really easy once I figured out what the ECU wanted.

I like the electronic controls, and I actually like reverse engineering wiring harnesses, other people love their mechanical controls. Not having to rely on someone else to do the tuning would be a BIG plus since there isn't much support for custom TDI applications, but there is some if you dig for it. Also, Rich's car is proof that an MTDI can be every bit as efficient as electronic, probably even more efficient when tuned by a competent person. I think he has gotten over 50 mpg with his 80, which is very impressive.

I'm not calling this car a success yet by any means, but my short test drive revealed that it actually is REALLY fun to drive and slide around on dirt roads. Sideways in the first 1/4 mile!

I still am not sure what is going on with my timing. I tried to verify my TDC mark on the flywheel and it seems very close. I had to advance the pump by one tooth after locking the crank and cam at TDC, and then i was able to dial injection timing right into where it should be.

Maybe my pump is worn out? Maybe the pump pulley slipped on the shaft some and sheared the key? I doubt that, but who knows. I suppose I will have to drive it some more to find out.

I drove it around with the timing set about where it should be, and HOLY SHIT this car is a hoot on muddy dirt roads. Good god, I build something awesome. Its loud and obnoxious and snarly. I'm sure its not blazing fast in a straight line, but it just begs to be tossed around. Winter will be very fun. It is so damn responsive, you would swear it has a vnt turbo. I am very pleased with that part of it, just not amped on the timing stangeness.

I even took it on the main paved road for a mile or so and got up to 60. Somehow the alignment doesnt seem insane, which is crazy since I have had every single part of the suspension off and replaced every single wear item. I guess my eyeball alignment isnt too bad.

My cruise control even works beautifully!

Really great job on the pedal. That took some serious thought and time.

I cant wait to work on a wiring job with no worry of "have to get it done today".

Dan McBoost wrote:Really great job on the pedal. That took some serious thought and time.

I cant wait to work on a wiring job with no worry of "have to get it done today".

Thanks man, its a little thing that is VERY important to get right. I was hooning this thing around so hard last night on muddy dirt mountain roads with bald tires and the pedal placement was just right for left foot braking fun.

Doing wiring harnesses is a fun challenge and super exciting to get it all working right. I enjoyed it on this car because I forced myself not to rush. Pushing the cruise control button and having it work perfectly was really awesome.

On a timing note, I found a bunch of threads on TDIClub forums where people with this particular flavor of TDI have to advance the injection pump by 1 tooth to get it to time correctly. Apparently its quite common, and no indication of any problem.

So screw it, I will proceed ahead with finalizing the project and continuing the mad dash to get it ready for Carlisle.

Also, there is some noticeable gear rattle at lower rpm's and at idle, which I more or less expected with a single mass flywheel. I converted my mk4 to single mass and it does this too, but the audi is more pronounced. Missing most of the interior makes it seem worse too.

I have heard some horror stories about a solid mass flywheel on a TDI breaking synchro rings in 01e transmissions. But I noticed all of these stories come from someone who sells flywheels and transmissions for 3x what I paid for mine in the same condition, so there may be some conflict of interest in that warning.

Time will tell, hopefully my setup holds together.

I've been a bit worried about that as well, hopi g the fluid damper helps..

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The gear chatter thing has been eating at me. I am going to call a couple clutch places and see if they can get me a sprung hub clutch that will hold 300-350ft/lbs and use a factory b5 1.8t DMF.

Apparently others have used the 1.8t DMF on TDI swaps with success. Emil has a heavy valeo SMF flywheel and clutch for a 1.8t and he says his makes no noise, but it looks like the clutch springs are much softer than what I have on my spec.

pulled the trigger, now it looks like i have a last minute clutch change to do before Carlisle.

So i got a new 228mm LUK dual mass flywheel for a 1.8t b5, and a southbend stage 3 daily clutch for that setup rated for 395 ft/lbs. The guys at southbend were very helpful and knowledgeable about TDI's and their vibrations. They were very confident that this setup would work well for me. Time will tell. Nothing like dropping money and hoping your making a good guess.

Car is going to have to travel with some primer and ugly trim I think. I wanted to get it all nice before its mainden voyage, but I think a good clutch and flywheel is more important.

Good call, no sense in risking your transmission.

FFFFFFFFFFF yeah. This makes me happy. Wanna do another one when you finish it up?

lets hope that poor DMF can hold up. Its so counter intuitive to add a DMF, I always take those things off and huck them into my scrap pile.

Hopefully a new, german made one will last a few years.

I mean they last until they don't on alh's. You should be fine.

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