Date: Thu, 17 Jan 2002 20:35:42 -0800
Reply-To: Michael Snow <mwsnow@COX.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Michael Snow <mwsnow@COX.NET>
Subject: Re: aircooled transaxle with 1.6NA diesel (LONG)
In-Reply-To: <22.222688c6.2978b073@aol.com>
Content-Type: text/plain; charset="us-ascii"
In the interest of greater understanding of Steve's experience with the
aircooled transmission and 1.6NA combination, have a look at this page on
Tom Carrington's web site.
http://volksweb.relitech.com/helmut/GEARBOX.HTM
The aircooled 091 transmissions all have the same forward gear ratios but
different final drive (differential, ring/pinion) ratios. 4th gear changed
a miniscule amount over the years. It is not important for this discussion.
Not coincidentally (look at the case) the diesel 4 speeds have the same
ratios for 1st through 4th gears as the aircooled models. Again, .03 is not
enough for me to consider a significant difference.
By using the early style shift linkage, it is possible to have an aircooled
transmission with the same or even lower gearing than a diesel tranny. The
bellhousing, input shaft, and shifter components what makes these
transmissions different. The aircooled vs. diesel discussion is pointless
unless you correctly identify the transmissions being compared.
From what I have seen so far, the DZ transmission is the most common model
on diesel Westfalia models in North America. It has the same gearing as the
DY model (5.86:1 ring/pinion) in the chart. The less common model is the
DM, with a higher 5.43:1 ring/pinion ratio. Notice that these are the same
ratios used with the 1600cc aircooled engine (same pathetic power levels in
a 5000 pound van).
Notice also that the DX (094) 5 speed used in 1983 North American diesels
has only slightly lower overall gearing in high gear than the DK model used
in aircooled Vanagons.
DK 0.852 x 4.57 = 3.89364
DX 0.77 x 5.43 = 4.1811
DM 0.85 x 5.43 = 4.6155
DZ 0.85 x 5.86 = 4.981
Because we hate to change clutches, I felt compelled to compare the overall
gearing of the highest listed 1st gear ratio for 1.6 diesels with the DK.
The difference is very small:
AAS 1.6TD 5 speed 4.11 x 4.83 = 19.8513
DK 2.0l 4 speed 3.78 x 4.57 = 17.2746
I can carefully get my 5 speed Westy rolling in 2nd gear without feeling too
badly for the clutch or lugging the engine. (DX 2nd gear is 2.33 x 5.43 =
12.6519).
It is probably possible to make good use of the DK gearing with the 1.6NA
engine as long as the engine is in good condition and the terrain is not
very steep. I would be willing to try this, especially with a passenger van
(mine are both campers). IMHO, diesel Vanagons were made marketable only by
the 55 MPH national speed limit of the early 1980s. You probably couldn't
give them away at the dealership today.
Hats off to you, Steve. I'm glad that someone had a transmission to
experiment with. My (often inadequate) math appears to support your seat of
the pants observation. I guess I should stop walking past those aircooled
Vanagons in the junkyards 8-)
Food for thought,
Mike Snow
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com]On Behalf
Of Steven Denis
Sent: Thursday, January 17, 2002 14:56
To: vanagon@GERRY.VANAGON.COM
Subject: Re: aircooled transaxle with 1.6NA diesel
In a message dated 1/17/02 5:46:56 PM Eastern Standard Time, mdlind@rica.net
writes:
<< Having the same torque at the flywheel at any given road speed
would not translate into having the same torque at the wheels with
two differently geared transmissions. >>
Don't do it then..I think I've covered this reallly really well.
I KNOW all this ratio crap (I said crap...can I say crap?) I'm an
*engineer*
for herbie's sake!..
HOWEVER the air-cooled tranny works QUITE well in the diesel van..
Instead of going buzzing around like an escapee from the Luftwaffa,
"arrrrrrrrrrrrrrrrhhhhhhh!" you drive it like a trailways
bus.."Hoooooommmmmmmmmmmmmmmmmm.."
NOBODY who has not tried it can tell you how well it works/doesn't and it's
NOT a big deal to undo if you DON'T like it!
I'm done with this subject (insert cheering here)
steve...