091/094 tranny to 412

func412 · Post by **func412** » Wed Oct 25, 2006 11:22 pm

Yes, that has been in my mind. There are several advantges in 901 gearbox. Longer gear ratios, 5 spd, type4 engine compatibility.

There are two main reasons, why I´m staying with VW trans; First, its Hard to find forged flywheels and second, a bit higher price (600-1000 euros with clutch and pp). So, the only advantage I see here is longer gear ratios...and maybe it would be a bit comfortable to use in a racecar.

Because of a flywheel setup I´ve been interested of 091/094 transaxle. It would solve one big issue of the setup; 228mm forged flywheel would give good grip and also would be a bolt on solution with the engine.

raygreenwood · Post by **raygreenwood** » Thu Oct 26, 2006 10:32 am

The 901 would have closer ratios being a 5 speed....but they will also be shorter. There are a great many available for the 901. For a twisty track...the short ratios might be nice.
Teh 412 tranny has very nice ratios for teh high revving range of teh original 1.7 it came with. Typically 65+ mph in 3rd gear is right at the upper end of the torque band in rpm. In fact 2nd and 3rd are nice.

But the real advantage of the 901 is that it is built tough to a known level. Among us...the 411/412...is kinda unknown. It may be tough ...it may not be. I don't know anyone who has really put moderate to big HP to it and spanked on it.
The other advantage...and teh biggest one for the 901....is that you can get parts for it. Expensive...yes....but certainly no more expensive than having a finished car sitting in the driveway waiting for parts that will never come. Ray

func412 · Post by **func412** » Sun Oct 29, 2006 11:48 pm

Ok, now I have some new information found by a member of FVWA (Finnish Volkswagen Association).

Source: http://www.suomenvolkkariyhdistys.fi/ke ... 6489#46489

I´ll translate this for you:

"Type 4 Variant has always had 3,91 final drive (toothed 11/43), as well as the limousine years -71 and -72 until may or june (there is some dissimilair information available from different sources about the month). The transmission code is FC.

Limousines -69 and -70 came with 3,73 final drive (toothed 11/41) with transmission code FA and after may/june -72 was the final drive also 3,73 in transmission coded FB.

In addition to these transmissions there has been a special transmission fon Variant coded FE which is toothed 10/39, so the final drive is almost the same as other Variant transmissions (3,90)."

tuna · Post by **tuna** » Tue Oct 31, 2006 12:36 pm

func412 wrote:First, its Hard to find forged flywheels and second, a bit higher price (600-1000 euros with clutch and pp).

The 914 flywheel is forged, it's pretty common, and it's perfect to mate to the 901. That's the combination I'd consider.

Tuna

func412 · Post by **func412** » Tue Oct 31, 2006 10:46 pm

tuna wrote: The 914 flywheel is forged, it's pretty common...
Tuna

Yes If I had a 914 flywheel I strongly would consider 901. Unfortunately in Finland the 914/4 flywheel is almost impossible to find. I´ve tried, and one 914 owner told me the same and had to design and make it by himself from CrMo. The reason is, there was not many Porsche´s in Finland in 70´s, not even 914.

The most car´s sold in here were "family cars" and usually one family had only one car. Even single living people wanted room for his car, because you should have space to take friends with you. 914 wasn´t good for that at all.

Nowadays the situation is different, because these kind of cars are used as a primary citycar, second family car and also rebuild by enhusiasts.

EDIT: I got the information, that the -69 411 trasmission mouting points are different than in later models. Don´t ask how different... I haven´t seen.

raygreenwood · Post by **raygreenwood** » Wed Nov 01, 2006 7:22 am

I can look in the original parts list for the exploded view. But....the chassis mounting points (those welded into teh car) should be the same. The difference is most probably in the mounting ears on the transmission. Those bolt on.
Also if teh middle crossmember over teh bell housing is of a different shape...that also bolts on and a later one could be used if there is a difference. Ray

tuna · Post by **tuna** » Wed Nov 01, 2006 11:48 am

I didn't realize that the car situation was so limited there. What about importing a setup from elsewhere in Europe? Is it too cost prohibitive?

Tuna

func412 · Post by **func412** » Wed Nov 01, 2006 12:03 pm

Yes, it might be possible to find one from Germany. Shipping from there is no problem. I even visit there at least once a year, it´s not so far. (We must make a 26 hour sea travel to go from harbour to harbour if going with own car. Then again there is some travelling on the road...)

Importing FW is the next thing I have to try.

Does 914 FW has it´s own pressureplate also or can VW 215 PP be used instead?

raygreenwood · Post by **raygreenwood** » Wed Nov 01, 2006 2:10 pm

Just a question....but what is so different about the Porsche 901 ....that keeps you from using a 215 VW flywheel. Yes...a 228 would be nice...and yes it is forged.....but unless you have crazy HP....I can generally get close to matching a stock 228 with just a little bit of work on a 215 and getting higher clamping pressures. Ray

Wally · Post by **Wally** » Wed Nov 01, 2006 11:27 pm

The 228mm holds the same torque but with less clamping pressure (less effort, even with a hydraulic clutch). All this from a stock PP

Or the same clamping force transfers more torque with a larger diameter disk, if you like.

Same reasoning porsche went from 215mm to 225mm in the 915 trans.

raygreenwood · Post by **raygreenwood** » Thu Nov 02, 2006 5:16 am

Thats what I figured. Problem gets into availability of parts. It may also be simpler when it comes down to leverage issues like that (especially when you do have a hydraulic clutch) to either increase the fulcrum length on the pedal (shifting the pivot point higher so the pedal is in effect longer but in the same position)....or to use a larger diamter slave cylinder.
I am playing with some things that may at some time allow some options on slave cylinders for 411/412 trannys. Ray

func412 · Post by **func412** » Tue Nov 14, 2006 1:14 pm

I just bought a 091 vanagon transmission and when I get it home I´ll figure out if the swap is doable.

What do you think, does any VW (or porsche) drive shaft match to 412 with 091 transmission?

Wally · Post by **Wally** » Tue Nov 14, 2006 1:52 pm

Its the same 100mm CV's for both, so whats the problem....?

raygreenwood · Post by **raygreenwood** » Tue Nov 14, 2006 3:14 pm

I think he is worried about the actual width of the tranny..from CV joint mating flange to CV joint mating flange....upsetting the shaft length.

But...and this is the beauty of the 411/412.....as long as you don't get silly in the adjustment........

the rear trailling arms......are in SLOTS on the rear beam. This allows you to properly center the trailing arms with refernce to the body...and can also allow something like 40mm of track width change.
So...you could work around some nominal amount of differential width difference....or even make allowance for wider rear wheels as long as you had driveshafts of the correct length. Ray

func412 · Post by **func412** » Tue Nov 14, 2006 11:03 pm

Yes, the length is the thing I´m worried about.

I cant use 412 original Cv's, because I´ve been told that the left and right side CV's has originally different length.

Ray, you possibly mean that the slots can be repositioned by cutting and welding? That would be good solution if the CV's length doesn't match correctly.

Lets see how long CV's I need and what is available in VW.

Another thing; this box is 091 gearbox with side shift (4.57 final drive and 0.852 fourth gear). Does anyone know if the 002 nose cone would fit into 091 gearbox?

It´s this kind of gearbox, which I´m trying to swap: