Diesel conversion - transmission options Options

[type11969]

Mulling over a tdi swap into my 914 while I should be working on dynamics HW . . . One big hurdle seems to be the transmission. 914 tranny isn't geared for a diesel and it would be expensive to re-gear it (if even possible). What other options are available? Seems like it would be convenient to use a VAG diesel tranny that was already set up for the tdi engine . . . but most are front engine front wheel drive. Anyone know of any VAG front engine RWD cars using a tdi engine? Old Audi, perhaps? I suppose a diesel Vanagon tranny might work but my guess is the gearing wouldn't be great in that either.

Other options? Linkage I figure I would do with cables.

Thanks,

Chris

[johannes]

Is this a joke ?

[Gary]

Pretty healthy discussion here: TDI thread. Looks like pre-B6 passat (longitudinal), O1E audi, or boxster trannys are all possible.

[RJMII]

I'd do it... 200 hp and 300lbs/ft of torque, and the radiator stays in the engine bay.... and not as much cutting up of the rear trunk.

oh, and 65mpg with that?

[rohar]

I'd do it... 200 hp and 300lbs/ft of torque, and the radiator stays in the engine bay.... and not as much cutting up of the rear trunk.

oh, and 65mpg with that?

Hmm, I'm about to put a turbo 2.0 16v vw engine in the teener (engine install is scheduled for winter). The block is similar enough to the TDI block so your comment intrigued me. When I had it mounted in the last chassis, I didn't have to cut any sheet metal in the rear, I did have to fab a couple of water flanges to make that happen, It was close.

How would you mount the radiator in the engine bay? Last time, I put a big old hole in the nose and mounted it up front as everyone does.

[Cap'n Krusty]

An Audi or Passat diesel tranny would be fine, but you'd need to fab a cable shifter. There haven't been any RWD Audis in decades, if there ever were any. As Vanagons were RWD with the engine in the rear, the tranny turns backwards in a mid-engine application, so that's out.

The Cap'n

[type11969]

Nope, no joke. I've been intrigued by the tdi engine for a long time. Thought about getting any one of the tdi powered vehicles but I have enough cars already. Figured the 914 needs an engine once I am done and the tdi would definitely be something different.

Thanks for the link, all good info. I'll post over there to see if any progress has been made.

I forgot that Audis/passats were set up longitudinal but still fwd, those would be the trannies I would be looking for. Vanagon definitely wouldn't be that desirable regardless but can't you flip the R&P? I would think that the sandrail guys that run mid-engine setups might do this but maybe they move past the bus trannies at that point.

Thanks,

Chris

[VaccaRabite]

Why not take the 2056 out of the bug and put the TDI in the bug? That way you could use a Vanagon trans w/o much difficulty.

And it would get the 914 that much closer to being done.

Zach

[type11969]

Really the tdi should go in the bus but I didn't want the bus off the road for so long.

I'm pretty sure the tdi or any VAG inline 4 won't fit in the Beetle engine compartment without some hacking to the engine lid. But that is a good point I'll look in to. Unfortunately it is only a 1.8 that I have in the Beetle.

I have an engine to put in the 914, a 1.7 that it came with that I would use until I've obtained all the parts for the tdi conversion.

[Dr Evil]

When you say regearing is expensive, had you considered flipping stock gears to get ratios that are more to your liking? Give me the RPM you want and I can look into it.

[type11969]

Hmm, no I had not. All good info. I'll have to get back to you on that, this is all in the very basic planning stages. I have a whole lot of 914 to finish first.

[Cap'n Krusty]

Just a little information about Vanagon trannies in general, and a couple of facts about diesel Vanagon trannies in particular. Vanagon trannies have a REAL problem with the 3-4 gear assembly. They break with irritating regularity. Practically every Vanagon that has been in here over the last 30 years has had at least one tranny replacement, nearly all for the same issue. Now, for the diesel tranny. Since the diesel Vanagons were imported for only 2-3 years (1980/81 to 1983), and the number was limited, where you gonna find one? They couldn't GIVE those things away when they were on the dealer lots.) And since the torque and HP of the original engine was probably half that of the TDI, what makes you think the notoriously weak tranny is gonna hold up under the added strain? BTW, you want to cruise at about 2000-2200 RPM in 5th. That's a 1000+ RPM drop from the stock 914 5th gear.

The Cap'n

[Porcharu]

Audi Transmission, the older 4 cylinder versions will bolt right up to the TDI. I think some of the newer ones have both the 4 cylinder and the 5/6 cylinder bolt patterns. Cableshift.com has a shifter for this setup.
Steve - wants to put a TDI 5 cylinder into my Oldvo.

[Cap'n Krusty]

And where do you propose to procure a 4K gearbox with diesel gearing?

The Cap'n

[pktzygt]

I looked into a diesel swap for my pathfinder. Sounds easy since they sold diesel Nissan p/u in the U.S. and I saw diesel pathfinders all over Panama when I was there last summer.

I never got past the law that "supposedly" says that you can't put a diesel in a vehicle that was not sold with one in the U.S. Then I got my 914 and all but forgot about the idea. Maybe someday I'll find a loophole like putting my pathfinder body on a diesel p/u frame.

Don't ask me to find the law. I heard it from a guy who had done the project and was having trouble getting it registered on NPORA (pathfinder forum) I think. All I'm saying is that there might be legality hurdles in there somewhere.

[okieflyr]

I would agree with going with an earlier Passat transmission since it is longitudinal. I'm not sure what your going to find to match your diesel though.
A Boxster style shift mechanism can work well with your own custom length cables. OR I still have my leftover low milage Kennedy adapter and clutch/flywheel setup if needed for a 901 conversion.

[aircooledtechguy]

Ask the guys at Go Westy about this 5-speed box. They may be able to custom gear it for you as well as flop the R&P to work in a 914. . . Worth a call anyway.

[Cap'n Krusty]

Ask the guys at Go Westy about this 5-speed box. They may be able to custom gear it for you as well as flop the R&P to work in a 914. . . Worth a call anyway.

Bring money ..................

The Cap'n

[SirAndy]

Seems like it would be convenient to use a VAG diesel tranny that was already set up for the tdi engine . . . but most are front engine front wheel drive.

Wouldn't a front engine front wheel drive setup be the same as a mid engine setup besides the location in the car?

You should be able to take that engine and transmission combo and just move it back a few feet.
(IMG:style_emoticons/default/shades.gif) Andy

[type11969]

Thanks for all the info guys, keep it coming.

When I think of front engine fwd I always think of a transverse layout. I forgot that audis/passats came front engine fwd longitudinal. So it seems like I am looking for a diesel passat (long. engine layout) tranny if such a beast exists. Or look in to gear interchangeability between later transverse diesel trannies and earlier longitudinal gas trannies. Or re-gearing of the 914 tranny, which sounds unlikely with the drop necessary. Hmm.

Thanks,

Chris