Vg turbo for 2.5 Di...a compromise

[andypdq]

Hi folks, We have recently bought a vw passat 1.9 tdi,1998 with vg turbo, and it has loads more bottom end pull than the trusty Audi 80 1.9 tdi which we had before. I am now considering fitting a vg turbo to my 2.5 di.
At present it has a Land Rover 200 tdi turbo fitted, ( I happened to have it lying around) on top of a modified na exhaust manifold, fitted upside down, feeding into banana inlet manifold, no intercooler, with bosch 145 pump and 100 hp brown spot injectors. This works well enough, but I would like as much low down torque as I can get, and I reckon a vg turbo would be better for this.
Question is, which one? I was thinking of fitting one off a 110 hp VW , same as the Passat, presumably it would be big enough, because 110 hp is more than the output of the di, so gas flow should be sufficient.
I'm not really a thrash merchant, so ultimate power is not my aim, I just want boost coming in as low as possible, with big mid range power, so presumably a smaller turbo is the one to go for.
Lastly, it has to be cheaply available secondhand, from a common vehicle ,loads about means easy to find, cheap replacements.
Your comments and sugestions for alternatives would be much appreciated.

Cheers.

[defi]

Trick is to get the turbo to spool up quickly with overspeeding.

[tlsjk]

go any pics of how it is at the mo

[andypdq]

Right, first a confession, I'm an imposter, its in a Sherpa, sorry about that! I reckon it would fit in a tranny ok though. Here are a couple of pics as it is now.

The exhaust manifold fits ok upside down, but because the mounting lugs aren't central you have to slot the holes to get the ports to line up, I then welded straps across the ends of the slots to strengthen it. I cut the mounting flange off the LR manifold and welded it to the Di manifold. Exhaust points forwards, it fit easier.

I like it with the turbo up high, everything is easy to get at!

Inlet was hooked up by butchering the egr mounting flange and pushing a bit of exhaust pipe through it, with lots of rtv sealant. I'm sure the banana manifold flows much better than the standard turbo one.

I had all the bits anyway, but had to get an oil feed pipe made, so it ended up costing me £35

[Mfr]

My only concern would be that it looks like the rubber air intake hose is in contact with the turbo outlet. To get round this I would keep the difficult engineering bit as is and fit an intercooler with the pipes away from the exhaust manifold. Nice project! I'd rather have a Sherpa than any modren' type van any day!

[andypdq]

The rubber hose clears the exhaust by about 3/4 inch, it's been running for about 7 months like this with no major problems and a massive performance increase, I'm really pleased with the results considering the whole thing was a scrapheap challenge type bodge.

However, the turbo oil seals are now on their way out, blue smoke on starting off, after it's been left ticking over for a minuite or two, serves me right for bolting worn out old junk on to it in the first place! So, something has to be done in the near future, thats how thoughts turned to VGT/VNT.

After a bit of research, it turns out, like most things, this will be a tad more complicated than I at first thought. To get optimum performance, vane control under differing load/throttle conditions is critical, much more complicated than a wastegate turbo. Pretty well all VNT's are fitted to electronic management system engines and the ecu looks after it. So, how to mechanically control? Fortunately someones already done it, a rather elegant solution it is too. Link, for anyone who's interested:

http://www.vwdieselparts.com/forum/view ... 2b3a95f9ee

I love the internet!

[Mfr]

Glad to hear! I managed to get a bit more oomph low down by replacing the wastegate actuator with a 10 psi one, fitting a k&n air filter, removing the cat and swapping the viscous fan for a electronic one, blanked the EGR and run with 250ml two stroke per tank. All adds up. I can't do more or I will upset the ECU. The turbo spools quicker than before and stays for a bit longer. Like yourself I'm not wanting to thrash about the place but its nice to be on a hill with the van full and leisurely move from brake to gas then pull away without grumbling. These mods only go so far, if you want more then a VNT might be they way forward but it looks quite difficult to do well. Would love to see a project similar to the one shown on a DI.

[F111ORY]

Hi Andypdq, I am new to this forum so forgive any errors.

I was interested to see you Di turbo set up using the landrover 200TDi unit. I have done exactly the same to a Transit Di in my series 3 landrover. Just like you fitting the transit manifold up side down and elongating the holes. I welded the landrover maniflod flange to the ford manifold and bolted the turbo to it. I fitted it facing the other way .



The torque boost towing is fantastic . I have now added an intercooler so I dont melt the pistons. I am just about to fit a standard transit turbo ( ebay) to my daily transport ( 1998 swb transit ) but first I have put it on a spare engine on a test bet and I am going to run it connected to the Dyno just to check the turbo has no oil leaks etc. Will put up a picture when i dyno it.

I also have a 1988 lwb transit camper and a bedford Cf cherry picker, both have the Ford 2.5 Di ! I plan to turbo the camper with a landrover turbo fitted above the manifold out the way of the second alternator.

Regards Rick

[øldabe]

here's another turbo-bodge in a landy. this one mounts exhaust forward and is inter-cooled.

[V184]

They certainly look better than the Land rover engined mk6 that was on here

[F111ORY]

Hi Oldabe, Is the Tansit engine available in the USA or was the Landrover converted in the UK and then exported?

I have intercooled my Landrover/Transit convertion now, will take some fresh pictures and post them.

Regards Rick

[V184]

Do they use Land rover gearboxes ?

[F111ORY]

Hi, No the standard Landrover gearbox is used with an adaptor ring made by a company in Chesterfield. Transit flywheel and pressure plate is used with a Landrover friction plate

The Transit gearbox would be such an improvement on the Series landrover box.

Regards Rick

[øldabe]

Hi Oldabe, Is the Tansit engine available in the USA or was the Landrover converted in the UK and then exported?

I have intercooled my Landrover/Transit convertion now, will take some fresh pictures and post them.

Regards Rick

Hi Rick. No transits in the US. Hunting parts has been an adventure, but i've made plenty of new friends over there and am single-handedly funding The Royal Mail.

Noticed the your exhaust exits rearward. How does it clear the lift pump and all? Just curious. Snap a pic of your truck too. I'd like to see it. There is another user here that's pm'ed me some advice who has a transit powered 109 as well. Cool club to be in.

[Jim Archer]

The answer to more low down grunt is fueling - assuming you have a turbo with an A/R ratio that suits the engine.

More fuel in a diesel increases exhaust flow, which spools the turbo, which 'boosts' quicker, which delivers more intake airflow, which can then use more fuel, etc, etc.

If the turbo doesn't spool up, or there's no bottom end shove, it means somethings not matched. For good overall performance the turbo ideally wants to be a bit small for the motor, and run a low boost pressure - hmmmmm, just like a standard 2.5TDI methinks - if you watch a standard EPIC fueled TDI accelerate from low revs you get a brief puff of black smoke from.overfueling that starts the turbo spooling up, then just a faint haze as the ECU matches the fueling to the airflow and off she goes.

If your N/A pump allows it, a bit more overall fueling will help get the turbo spinning, but without the exhaust flow it isn't going anywhere, hence these modern high powered turbo diesels are as flat as a pretty flat thing off boost and take ages to spool up, it's the emmissions concious progamming of the ECU not giving enough fuel to spin up the oversized turbo required to get decent HP out of a tiny little diesel engine.

Jim