TDI + flipped Passat trans upgrade

[markd89]

Great stuff!!

Having done the 091, I think the flipped trans is really the better way to go. The gear-shift which you came up with solves what seemed like the last remaining issue. If you go into business and make a kit, I'd be on the list for one When my very spendy 091 is worn out, I'd like to upgrade.

I'll be curious to see your MPG when done. I routinely see over 30 US MPG. What kills the mileage is higher speed 60-80 MPH. If I had a 5th gear to drop me down to 2200-2500 RPM, I suspect I could see a few more MPG overall.

Mark
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78 TDI Sunroof Bus
Los Angeles

[GfunkBus76]

Wish your photos still worked! Anywhere I can check them out? Going to watch your videos at least.

How's it been treating you?
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Gavin
1976 Westy - Customzation in slow-progress.
-8V TD swap
It Runs! -- http://youtu.be/kT5hOtwiOgk
And drives! - https://youtu.be/rVkoAgeOop0

[trevorbrady]

The photos worked until last week when photobucket killed the internet. I'm not going to pay their ransom so I'll have to figure out another way of hosting the pics

[vwwestyman]

Just upload them to The Samba gallery for free. That way they'll last as long as The Samba itself!
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Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[nemobuscaptain]

[KMT]

Any more updates? Looking forward to seeing the progress.
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Jamie Auch
The Kooky MathTeacher

'68 Panel
'78 Champagne Edition Westfalia
'89 Blue Star
‘90 Hightop TDI Vanagon
'90 AFN TDI Leisuredrive hightop
http://www.highcountrybusfestival.com
Pisgah Bus Rally

[trevorbrady]

I've rehosted the pictures, they should all work again

updates...

hmm... I have about 5000 miles done on the TDI conversion now and if I take it easy on the pedal (like 60MPH or less) I can get 45MPG. However, once I get on a motorway I just hit 80MPH and stay there all day! As a result I'm getting closer to 35MPG. Which isn't great for a TDI but at the moment I don't mind.

In the last 12 months or so since I completed the TDI conversion I've had thankfully few issues and haven't had to do too much more work on it. Most work has been due to the 20 year old parts on the TDI engine wearing out or coming to the end of their lives. For example the N75 valve gave up and it stopped boosting. A 10 minute replacement had it sorted. Just last week it burst a small hose off the back of the water pump. It took an hour to get the pipe off and a replacement on but that's put to bed now too.

I was getting a few small boost leaks in the DIY pipes and hoses I'd made up so I replaced all the rubber bits with silicone hoses and flared aluminium joiners. Problem solved.

I am now concerned that the intake air temperature is too high and that's due to the total lack of airflow to and through the intercooler. It's heat soaked. So the next modification I will make will be to get a smaller intercooler and position it in the airflow to the left of the engine. It should lower the IATs. They're hitting 90 degrees Celcius on a cool day here and I saw 100 degrees Celcius on a hard motorway run on a hot day during the summer.

The only alteration I've really made has been to lower the engine by 1" and replace all four CV joints. Even though the previous ones were new for the conversion, the engine was set just a shade too high and they were just in the "uncomfortable" region of their range. They wore out and were clicking. So lowering the engine an inch put them back in their comfortable range and replacing the CVs finished the resolution of the issue. There is only 5" under the sump now and TBH, it looks low when viewed from outside but it hasn't caught the ground once so I'm happy to carry on.

The van is being used regularly for camping, towing, touring etc

[skills@eurocarsplus]

your IAT's are insane....

there is no real useable airflow in the engine bay. your best be would be an air to water IC. yes, there is plumbing involved for sure, but there is plenty of space to do it.

a good friend of mine is using a killer chiller on his super charged monster...highest IAT's in 100* weather were 68* on a mile long blast @ 24 PSI.
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[markd89]

[vwwestyman]

Do you have the battery tray open? Fan underneath? If you do those things that should help lower the IATs somewhat. If that intercooler is just sitting there then you aren't getting any air flow at all so I can see why your IATs are so high.

I have a water to water intercooler and second Mark's thoughts on making sure everything is over spec'd for it to work well with a TDI in a Bus. I don't remember the original spec of the intercooler I used but it theoretically was for a significant amount of horsepower higher than I'm making.

That may be part of my problem, and also part of the problem is I undersized the radiator because I bought what would fit strapped to the front suspension on the right side (away from steering parts and all that) so it is too small.

I tried to add a little more surface area by plumbing in two copper manifolds on either side of the frame but that didn't make an appreciable difference.

Going down the interstate a few weeks ago, I saw temps up around 180 at times.

Unfortunately I don't think I have much of a record anywhere, but I think my long-trip intake temps with the current water setup are about the same as what I was seeing with my intercooler mounted like you've got yours, with a fan pulling air through it. I blocked that area off from the engine, so the fan was pulling air from the upper vent.

So I added a lot of complexity (intercooler, plumbing, pumps, more coolant to bleed, etc) for very little benefit.

Unfortunately I don't think the ice tank system Skills mentioned is as helpful on a TDI on a long road trip. Crazy how effective it is for a short run, though!

What are your engine RPMs at 60 MPH? Higher highway speeds? I don't ever see 45 MPH in my Golf, but I also don't drive it slow.
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[trevorbrady]

[richparker]

Athough I run a ACVW engine not a WC one, I do have my external cooler in the same location as your intercooler. My battery tray is cut out and the cooler sits in a custom mount, what a difference it it having air flow over the cooler and out the bottom. I would recommend putting the fan on top pushing the air instead of underneath pulling the air. This way the fan is out of the elements and there is a good chance the heat from the cooler can melt the fan if pulling. I also used a thick metal mesh to make a cover underneath the cooler to protect it.
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__________
’71 Westy build
Adventure thread
’65 Deluxe Build
’63 Deluxe Build

[markd89]

Dave, on your setup, it would be interesting to measure the water temp in the A2W setup vs. the air temp. I recall when I did this, I saw a big difference. That told me that my issue wasn't that the water wasn't getting cold enough (radiator issues) but that there was not enough heat transfer in the intercooler (hence the 2nd intercooler).

Rich is right. Making a hole and adding a fan will definitely help. I also tried this. I tried many things I don't remember what the numbers were but they were not great - I would guess 150 or 160 *F. Hence my original post (go BIG BIG on A2A which is what I would do today or go BIG with A2W like I did).

One thing I didn't do which would probably also work better than the battery tray hole- cut a hole in the side of the bus and route a duct to the intercooler with air exiting from another hole in the back of the bus (or maybe underneath). That would be dramatically more airflow than a fan will give, BUT at the price of a hole in the side of the bus. I wanted a stock appearance and so this was a non-starter for me.
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78 TDI Sunroof Bus
Los Angeles

[tristessa]

[vwwestyman]

[tristessa]

Just had a thought occur to me -- rather than cutting holes in the side (visible), why not tap into the natural higher-pressure air at the rear of the wheelwell behind the tire? I realize there's the potential for dirt/debris to come through, but...

[vwwestyman]

[Air_Cooled_Nut]

From what I've read and what is in this engineering paper, the higher pressure air region would be around the upper-leading area of the tire (right side of below text)

The upper trailing area would be a lower pressure region.

As further evidence of this, I know VW uses this area for intake induction on its Mk3 passenger cars. Other manufacturers have used this area as well.

So if one was going to place an intake or radiator about the tire I would think this area would be best. Personally, I wouldn't do this due to the great opportunity for debris to pop a hole into anything there or possible even pushing a tire into it if not sufficiently spaced.
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Toby http://www.aircoolednut.com/
Did I mention that I'm an original Darksider?
'72 VW Squareback, 2007cc, GB 5-speed, rag top; '76 VW Riviera Penthouse Sundowner 2.0L; 2015 Audi S5 Cabby w/Stage II APR; '06 Ducati Sport Classic 1000; '14 Ducati Diavel Strada
The First Invasion

[tristessa]

IAT's

I finally got off my ass and slapped a fan on my intercooler last night, wired to be on constantly while the key is on. This is a 20V 1.8t with the Passat trans not a TDI, and my intercooler sits on the passenger side near the battery in an area of little apparent airflow.

This afternoon coming home from work I had VCDS-lite logging (among other things) IAT's and coolant temps .. was going to log on the drive to work this morning but I forgot to hit the "log data" button.

Anyway, on my ~10 mile drive of mostly freeway in 98-99F temps, my IAT's with the fan on the intercooler never got over 137F (58.5C) and coolant temps stayed right at 195F (90C). I don't have any recent data on IAT's but I remember seeing 145-155F (65-68C) when running around monitoring things with VCDS-lite when I first got the motor in & running, and ambient temps then were more like 70-75F. So a fan definitely helps.

Next step on the IAT data gathering is to do the same drive in similar temps with the fan disconnected. Maybe tomorrow if I'm feeling ambitious.

[vwwestyman]

I happened across this thread while looking for something else a few days ago.

Anyway, I just drained some of the water in my system and refilled with coolant. Had some issues last summer on a trip and realized that it was mostly water...

It was sure a pain trying to get the air out and get coolant in there. I realized I sure need to get something better together. Whether that is improving the current system, or changing altogether, it is not that great right now. Something needs to change in my system.
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing