Gear ratios for TDI -> Bus conversion

[diesel smoke]

Well I'm wanting to make myself a ALH mTDI to install in my Bus and am just looking to gather info on the conversion. However I do know that I would need to re-gear the transmission so the engine runs at an appropriate RPM. So my question is what gear ratios would be needed for my bus? I know a few of you have converted a Vanagon to TDI, and the stock transmission, and gear ratios are pretty much the same for the gas versions between the Vanagon and my '73 with a 002 trans. Also, if someone could point me in the right direction to where I would get these parts and maybe some stronger ones, I'd appreciate it.

Thanks! 

[monkey magic]

Hi mr smoke,

You dont say if yours is a syncro or not. If not, are you 4 speed or 5 speed?

i TDI'd mine, (a syncro, so for arguments sake, 4 forward gears) but havent yet got a proper box built up for the job. I am running with the original JX/TD ratios, and stock wheels and tyres and darent go over 60MPH due to revs! Not sure without checking which C&P I have, but out of the 5 out there, i believe mine is the middle one.

I think the general attitude to it is get a petrol box, or go for the 2nd tallest C&P and increase the top 2 gears. Brickyard has a chart with the ratios/box codes/engines on, that will help.

The only proper way to do it is to look at the available gearsets, and look at your torque curve, and plot it all out on paper.

As for source, I think most people are using albins gearsets, not cheap though (esp. not if your in the uk  ).

I'll find some links for you later..

 

[diesel smoke]

Thanks, libbybapa is right. It's air cooled right now and there never was a Syncro for the Bus...well at least not sold to the public. And there was only the 4 speed manual, and '73 was also the first year for the 3 speed auto, but got the manual.

I know a few of you have converted Vanagons, so I thought I'd ask here. 

[monkey magic]

Bus refers to the earlier air-cooled bread loafs, none of which were syncros or 5-speeds.

Sorry, but this isn't universal. Where I come from, 'bus' is used to refer to any of the VW vans. In days past it wasn't uncommon for people over here to refer to their cars as a 'bus' too. Clearly this is a regional thing..

Am I to assume then that you want to mate this engine to a 1970's 4 speed gearbox? Surely if you're going to go to the trouble of having a box built you would use a more modern unit, which would then allow you to go 5 speed. I have often reconsidered my syncro build, toying with the idea of going 2wd so I can run a 5 speed box to make the most of the TDI rev range.

[diesel smoke]

Yep, I want to have a trans built for it. An 002 4 speed. However I have no clue where the heck I'm gonna get a 5 speed box for it. I've yet to see one here. I'd be content to having a 4 speed, this thing doesn't need to be a rocket, it just needs to be able to maintain highway speed up a hill or in a headwind. Something the 1800 T4 just can't do.

[monkey magic]

Sounds about right Libbybapa, I read a blog last year by a guy who was fitting a PD TDI to an aircooled (T2 I believe, we call em bays over here). As I remember, he did have to do some major butchery, and it was a project that lasted years. I don't know much at all about the early 'buses' tho.

I know that people do mod the old boxes and put a lot of power through them, used for drag racing etc! I'm sure they invest a lot more than some new gearsets to make them durable though.

[diesel smoke]

Basically I'm asking for what gear ratios would be best for this thing.

FWIW, here's a pic of my rig:


More pics from the club camping trip here:
http://www.airriders.ca/phpBB2/album_cat.php?cat_id=59

[moTthediesel]

Sorry I missed this thread, but I don't usually check this section of the site.

I just had Rancho Performance  in California http://www.ranchoperformancetrans.com/service.html make me a new trany for my Porsche 356. I went with crazy tall gears (3.78/2.06/1.21/0.70/ with a 3.44 r&p) in mine, but my car is very aerodynamic and small and weighs only about 2000 lbs. I'm quite sure you're going to want something shorter, but they could certainly help you to decide what you need for ratios in your 02 box. The guy I worked with is named Mike Herbert and he was very knowledgeable. He wasn't even shocked to be asked about options for a water cooled diesel engine in an old Porsche, so I'm sure he'd work with you on it.

Cool project, good luck with it!

[diesel smoke]

Thanks moTthediesel. 

[svenakela]

It looks like you're happy to have a 091-box. Good stuff.
If you'd like to laborate with gearings, check out Richard Ratwell's gearbox stylesheet. Mr Ratwells webpage is a good source for any VW bus related info.
http://www.ratwell.com/technical/FAQ/images/091BusGears.xls