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Author Topic: Petra Passat  (Read 17358 times)

Reply #30July 20, 2017, 07:53:00 pm

vanbcguy

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Re: Petra Passat
« Reply #30 on: July 20, 2017, 07:53:00 pm »
Made up a quick rubber patch and headed out to the fabricator that did my intercooler install this morning. They repaired the damaged pipe and spotted another bracket that had cracked, guess they aren't used to the vibrations of a diesel! The other bracket (which supports the air filter) was triangulated and is much stiffer now.

After all of that I finally got to drive with boost! Woohoo! I cranked my fueling down a bunch when I was driving without the turbo, my EGTs are peaking at under 600°C right now so there's room for more fuel. I have the boost dialed back a little too.

The noise of the air rushing through the K&N is down right irritating. It's LOUD, and not in the "turbo whistle" way, more in the "crazy amount of air rushing through a fine metal screen" sort of thing. I'm going to have to sort something else out. Really wish we could have kept the stock airbox... I need something that has its outlet closer to the bottom though.

Oh yeah, my boost controller appears to be working fine. I'm seeing the vanes fully closed a bit more than I remember with my Jetta - the FMIC vs the AWIC might have something to do with that. I also reclocked the turbo when I had the engine out so my actuator might need some adjustment. However it is certainly doing its job and keeping boost regulated well!

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« Last Edit: July 20, 2017, 07:56:26 pm by vanbcguy »
Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #31July 21, 2017, 09:21:51 am

air-cooled or diesel

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Re: Petra Passat
« Reply #31 on: July 21, 2017, 09:21:51 am »
The noise of the air rushing through the K&N is down right irritating. It's LOUD, and not in the "turbo whistle" way, more in the "crazy amount of air rushing through a fine metal screen" sort of thing. I'm going to have to sort something else out.

you can try to make another circuit board, this one you can put turbo whining sounds on it, adjust for rpm and vss, perhaps hook up to former ecm connectors so it can sense these. it would have to be like really "LOUD" (can you hear anything over this &the intake sound?), and hook it up to like your sound system. lol.

id say strategic sound deadening. perhaps at,near the base of the intake filter (area), put a type of contraption (its hard to print what im visualizing) that will go around (intake or filter,base) and is angled away from passenger cabin (cannt think of angle, ?running parallel to firewall?) perhaps with angles or tabs, again away from cabin, (or slightly in on its self) and add sound deadening, to deflect, lessen sound.

Reply #32July 21, 2017, 09:28:18 pm

vanbcguy

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Re: Petra Passat
« Reply #32 on: July 21, 2017, 09:28:18 pm »
I was looking at some ammo boxes today that might make good filter housings. The price was a bit dear so I left that for another day, but I could see it working. Of course the alternative is to spend a bunch of money, get some of the pipe work redone and use my factory airbox like I wanted to in the first place... I also thought about just cutting a hole in the factory airbox and putting the cone filter in there (the reason I can't run it is the top outlet, my turbo to IC pipe is in the way).

Did some more tuning and adjustment today. Messed with the actuator and stop screw settings; got the turbo in to the actual control range of the N75 under most circumstances. I think the stop screw could still come out another turn but that requires me getting the car in the air and yanking the belly pan so it won't be happening for a while. I could probably do with shortening the actuator rod a little too but I think I need to pull the turbo to do that. The actuator bracket had a little adjustment but it's at the end of its travel now, any further adjustment will have to be done with the turbo out of the car. Ugh.

Fuel screw went in about a full turn. Still virtually smoke free with the pedal to the floor and EGTs still below 650C so I can still push a fair bit harder. I think the FMIC is providing much better IATs than my AWIC was as I had no trouble hitting 850C in the Jetta. Now I have a heavier car and I'm running with about 5 PSI less boost but seeing lower temperatures. The fuel screw is almost to the collar now.

I think the stop screw must have been pretty wrong on the Jetta too as I'm fairly sure I cranked it out a half turn or so while I had the engine out, then another full turn today. That's a pretty big adjustment. The boost comes on pretty fast now, first time I've been pushed in to the seat since I bought the car however long ago now.

I fixed a few things in my Arduino code too which has allowed me to increase the sampling frequency. I think the VW N75 valve is faster acting than the GM one I was using too - I'm seeing much more immediate response from the turbo when the duty cycle changes. I'm having to remove some of the code I had previously to try and overcome lag in the control system.

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Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #33July 21, 2017, 11:54:46 pm

vanbcguy

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Re: Petra Passat
« Reply #33 on: July 21, 2017, 11:54:46 pm »


This is where I'm at. The actual control is pretty good, boost is pretty close to requested. However the duty cycle is jumping around a lot more than it needs to - that'll wear out the VNT mechanism in the long run if I don't calm it down. I need to make it a bit less aggressive.

The "stuttering" just over 5k RPM is actually the LDA control starting to vent pressure - I have it set to act somewhat like a rev limiter as well as limit EGTs. I actually didn't realize it was coming in to play, I need to turn it down a bit as I wasn't expecting it to have any impact till closer to 6k RPM.

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« Last Edit: July 21, 2017, 11:58:10 pm by vanbcguy »
Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #34July 28, 2017, 10:21:03 pm

vanbcguy

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Re: Petra Passat
« Reply #34 on: July 28, 2017, 10:21:03 pm »
1200 km of road trip later....



Lots of sustained high speed driving - limit is 120 km/h up the island highway, complete with the odd stoplight. Had a few opportunities to do WOT 0-120+ acceleration runs. Very fun. Nice tire squeak going in to second.

I somehow set out with my mini laptop with a dead battery so had no opportunities for tuning or logging. I know I need to make some tweaks still, I'm still having some flutter at 3k+ and my 29 PSI target. It'd not varying a ton but it's hunting around as detailed previously.

EGTs are great. The new intercooler is definitely doing a better job no two ways about it. It was hot today - 30+C. Uphill WOT  run up to 140 umm I mean 120 km/h and EGTs still safe. Oh yeah fully loaded down with camping gear including a full load on the roof! Well minus the 20L water jug that disappeared at some point along the way... Oops.

Yesterday was about 5 hours driving all together, all mountain highways. The car is a joy to drive in that scenario - it's what she's built for. Power delivery is super smooth. Mmmmm...

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Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #35August 02, 2017, 07:34:51 pm

vanbcguy

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Re: Petra Passat
« Reply #35 on: August 02, 2017, 07:34:51 pm »
Eureka!

I've been having issues stabilizing control over the turbo all the way back to my Jetta. Yesterday I figured out that there was a bug in my code - I wasn't actually acting on the latest data sample when I was making control decisions. Effectively I was setting the turbo to handle what I'd read 50-100 ms ago, not "now". Duh. It's leftover from me making some changes in the control logic that probably stretch back to the start of the damn project.

Well that's fixed now! I have stable control. Here's a solid pull through 3 gears...



A little overshoot but no big deal, hitting 2.15 bar with a 1.95 bar target. I can deal with that - I could probably tone it down but I'm good with it.

EGTs hit about 650°C and stay pretty much flat - that's awesome too. Means I can basically have it floored all day without having to worry.

Small stop screw adjustment on the turbo wouldn't be the worst thing, could close the vanes a hair more. I probably still could do with having the actuator rod just a wee bit shorter but I'm really not interested in pulling the turbo to do it.

Anyhow glad that's finally sorted. I'm sure my car will appreciate being used as a car eather than me just driving around in circles to the same highway on ramp again and again to go WOT.

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Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #36August 03, 2017, 07:08:15 pm

libbydiesel

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Re: Petra Passat
« Reply #36 on: August 03, 2017, 07:08:15 pm »
That looks awesome.

Reply #37August 08, 2017, 03:07:04 am

vanbcguy

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Re: Petra Passat
« Reply #37 on: August 08, 2017, 03:07:04 am »
Nice 8 hour drive Vancouver to Spokane, WA...



Everything is running well. Definitely a lot more fun to drive with the TDI vs the AAZ!

The astute might notice my new wheels. Liking them big time!

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« Last Edit: August 08, 2017, 03:10:18 am by vanbcguy »
Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #38August 08, 2017, 07:55:41 pm

air-cooled or diesel

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Re: Petra Passat
« Reply #38 on: August 08, 2017, 07:55:41 pm »
both the rims you have on this page in pics look good.

isnt this the last model that had the 4bolt weaker pattern. i had always thought the mk2 was a little big for a 4bolt wheel pattern, and the mk3s (&b4 models) were a good size too big for the 4 bolts. ive never had a problem with this, although know its a 'design defect'. wasnt it here where the whole industry went to a -minimum of the 5bolt pattern, except for certain small models. the 5 bolt pattern is at least 20% stronger @ the attachment.

Reply #39August 08, 2017, 08:01:19 pm

vanbcguy

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Re: Petra Passat
« Reply #39 on: August 08, 2017, 08:01:19 pm »
VW did 4-bolt on everything until they went for the VR6. The "load" of the car is taken up by the clamping force between the wheel and the hub, though the bolts are definitely involved in torque transfer. I always figured if a G60 Syncro could handle 4-bolt a TDI should be fine!

I liked my last rims looks wise but they were a no name brand and ended up bending quite easily. Never tagged a curb or anything, just whatever bumps and potholes I'd encountered in normal driving bent two of them.

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Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #40August 21, 2017, 07:55:11 pm

vanbcguy

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Re: Petra Passat
« Reply #40 on: August 21, 2017, 07:55:11 pm »
Turbo carnage!



When I swapped the engine in to the Passat I noticed a little nick in each of the primary compressor blades. I wasn't sure what was going on - at the time I thought since they were all pretty uniform it must have been made that way. Guess not!

Pretty sure I fatigued the turbo pretty good back when I had the engine in the Jetta. I know I hit 35+ PSI more than a few times. Add in the episode with the big hole in my boost pipe and I can explain why I wasn't seeing boost come on as quickly as I would have expected...

Ever since I got the control system together in the Passat I've been noticing it was taking a lot more N75 duty cycle to get the boost I was requesting than I was seeing in other people's logs. Over the past while I've been really noticing it wasn't behaving right at all - I was having trouble achieving my requested boost on some longer pulls where I would have expected overboost to be the issue. Then last week it finally gave up the ghost...



Boost suddenly dropped off, then the turbo started whining like crazy, though it was still producing boost. I prepared myself for a possible runaway and made my way back home. Opened it up today and found the carnage in the first photo.

Well, now I know why I was having to push the turbo so hard!

There was a bunch of grey fuzz and n the turbo outlet which I'm expecting is powdered turbo wheel. Going to have to clean out my IC for sure. Hopefully not too much made it in to the engine.

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Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #41August 22, 2017, 04:46:36 pm

vanbcguy

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Re: Petra Passat
« Reply #41 on: August 22, 2017, 04:46:36 pm »
Siiiiiiigh. From the "boy, do u feel stupid" department.....

Noticed when I was taking everything apart I was missing a rubber sealing ring from my air filter. Figured I must have not used it in the end (it was a thin ring to adapt the cleaner to the pipe I'm using but not strictly necessary). Welllll it isn't in the box. And the black fuzz that's all through my intake? Yeeaaaahhh I tried hitting a bit of it with my torch. Burns like rubber. Smells like rubber.

D'oh.

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Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #42August 23, 2017, 07:28:26 pm

libbydiesel

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Re: Petra Passat
« Reply #42 on: August 23, 2017, 07:28:26 pm »
Bummer!  Do you think that the missing sealing ring caused the damage or just over-speeding?

Reply #43August 23, 2017, 07:46:29 pm

vanbcguy

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Re: Petra Passat
« Reply #43 on: August 23, 2017, 07:46:29 pm »
It definitely caused the damage. There's shredded rubber everywhere. Now I'm not so sure anything happened beyond the ring getting loose, though I still think my turbo wasn't totally happy to begin with.

Expensive mistake but there you go. All I can do is blame the engineer, myself!

New turbo ordered...

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Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #44September 08, 2017, 09:22:09 pm

vanbcguy

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Re: Petra Passat
« Reply #44 on: September 08, 2017, 09:22:09 pm »
Finished getting the turbo swapped out today. Had to use both the compressor and turbine housing from my old turbo as they were both a bit different despite both turbos being a GTB1756VK.

The replacement turbo seems to be spooling quicker than the old one. I'm also seeing a lower (vanes more open) N75 duty cycle too. I only have one log that's just me driving around the neighbourhood but my cruising vane position is much better.

Expensive mistake to make. If anyone wants a GTB1756VK that needs a new compressor wheel hit me up!

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Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

 

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