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Author Topic: Petra Passat  (Read 17343 times)

Reply #45October 18, 2017, 04:21:45 am

air-cooled or diesel

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Re: Petra Passat
« Reply #45 on: October 18, 2017, 04:21:45 am »
so, i ve been meaning to ask a question in the m-TDI section. not really to you van, as your motor is rather hopped-up, but in a close to stock set up and/or some what extra output, perhaps some of it being a turbo. whats about the mileage? id prefer to go with a manual,mechanical wastegate set up.

Reply #46October 18, 2017, 11:25:42 am

vanbcguy

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Re: Petra Passat
« Reply #46 on: October 18, 2017, 11:25:42 am »
I've been getting around 5.5L/100km on my last few road trips (about 42mpg). I don't drive with a particularly light foot and that's been with bikes on the roof too...

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Bryn

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

Reply #47October 18, 2017, 12:23:28 pm

air-cooled or diesel

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Re: Petra Passat
« Reply #47 on: October 18, 2017, 12:23:28 pm »
ok so now i need more info, cause as you all know i have at least 1 mk3. and im getting about 40mpg w/o a light foot at hiway speeds, 70mph or so. so what i had heard was an m-TDI may get 35mpg, so what else are you doing? cause you have performance options, i for one figure 5 gear, youve swapped in a higher one.

Reply #48October 18, 2017, 02:24:23 pm

vanbcguy

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Re: Petra Passat
« Reply #48 on: October 18, 2017, 02:24:23 pm »
ok so now i need more info, cause as you all know i have at least 1 mk3. and im getting about 40mpg w/o a light foot at hiway speeds, 70mph or so. so what i had heard was an m-TDI may get 35mpg, so what else are you doing? cause you have performance options, i for one figure 5 gear, youve swapped in a higher one.
Transmission is a CTN code 02A from a TDI Passat... Nothing changed other than a rebuild and an LSD. Injectors are big honking 0.260 HFLOX. I have a large FMIC, decently free flowing exhaust (though it still has a muffler)... I have my pump set up to keep smoke to a minimum but she'll still blow black if I load it up before the turbo is ready and there's a decent haze behind me at full load.

I was 5.2L/100km on a trip mostly involving secondary highways across Washington state and BC - lots of mountain passes. 5.8L/100km on my last run to Portland and back on the I5 mostly 5-10 over the speed limit.

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Bryn

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

Reply #49October 21, 2017, 11:00:16 am

air-cooled or diesel

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Re: Petra Passat
« Reply #49 on: October 21, 2017, 11:00:16 am »
it had slipped my mind you had a passat. so its the same engine as the jetta, 1z, or ahu. the tune is the same, engine management. is the gearing the same? as the mk3 jetta? just to ask w/o doing research, perhaps the trans case has some differences. other than that its your m-TDI conversion, and turbo, i forget bigger turbo? along with some mods, and your tune.
getting some info together on this subject. for one my mk3 jetta, as is well known, has fuel mileage from 40-42.x mpg, in which case i have no idea why the passat has better mileage(as stock), and your m-TDI is killing it. in the future i have some options for a conversion(s).

Reply #50October 21, 2017, 02:13:40 pm

vanbcguy

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Re: Petra Passat
« Reply #50 on: October 21, 2017, 02:13:40 pm »
The engine itself is an AHU from a Jetta, but there's not really much left that makes it an AHU. Since mine is M-TDI there's no tune / engine management really. The injection pump handles everything fueling wise.

The head is still stock AHU. I have a Colt Stage 2 cam, ASV pistons (they're the same compression ratio and everything but they have a better setup for cooling the dome), Integrated Engineering rods... I can't really see any of that impacting FE much. The cam might help a little.

Turbo is definitely larger. Mine is a GTB1756VK which is a newer design than stock.

Really I think it comes down to having the car in overall good shape. Good alignment, wheel bearings have been done on all 4 corners, brakes are in good shape, I run legit summer tires in the summer... Tire inflation alone can knock you a few mpg either way.

I should add too that I don't get anything like those numbers driving around in town. Especially not if I'm romping on it a lot. Juiced up diesels like their fuel when you're pushing them hard.

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Bryn

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

 

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