Torque Convertor

wildthings · Post by **wildthings** » Tue Jun 08, 2004 11:31 pm

Is anyone running anything other than the stock torque convertor on their 411 or 412. I talked with the guys that rebuild 003's in the bay area and they said it was easy to swap a torque converter out of a later bus into the Type 4. I would think that the higher stall speeds and deeper convertion ratios of the later torque converters would give vastly improved performance over stock. I'm figuring on replacing my engine in the next 10-20 thousand miles so if this swap is worthwhile to do, I would like to be hunting up a later model torque converter now in preperation for that day.

raygreenwood · Post by **raygreenwood** » Wed Jun 09, 2004 5:47 am

The torque converter is the same on the bus and the type and the 411/412. They all have a torque multiplication of 2.5 and a stall speed of 1900-2100 rpm. Identical.

I am sure someone somewhere at least used to make a high performance converter...but its not really necessary. You can generally wrap these things up to the limits of the injection on these cars. Also, if you really wanted better off the line, you should see if B$M (if they are still in bussiness) makes a valve body shift kit or a mod for the governor. Ray

DeathBus · Post by **DeathBus** » Wed Jun 09, 2004 7:32 am

I had my 412 Auto doing 100mph down I-65 yesterday, its an automatic 1700cc. Seems the Torque converter worked fine.

wildthings · Post by **wildthings** » Wed Jun 09, 2004 3:21 pm

Ray, I'm thinking of using a Code Z converter out of a 1982-85 air cooled vanagon or a Code H out of a water cooled Vanagon. I haven't seen the specs on either, but I know that my 91 Vanagon has a stall speed around 2800-3000. The Bentley manual for the Vanagon says that the Code Z can be used in place of the Code D, the Code Z will supposedly runs cooler than the D as well. Do you have specs for the Code Z or Code H converters.

raygreenwood · Post by **raygreenwood** » Wed Jun 09, 2004 6:24 pm

hee hee ...i just answered that this is probably what you needed (3000 rpm stall point) in the type 4um. The interesting thing is this, the final drive and 4th gear...and tire diameter...make the bus very able to use around 3k on the auto lock-up without having any ugly problems. I take it you are racing this type 3? If so..this should be cool. If not...its going to be hard to drive on the street. I will check my books. The vanagon and waterboxer I am not very familiar with.
The type 3 with auto has a final drive of 3.67:1 with a 1:1 3rd gear.
The late bus (not vanagon) with auto...had a final drive of 4.45:1.
Ray

wildthings · Post by **wildthings** » Sat Jul 09, 2005 11:22 pm

Well I finally got around to swapping out the torque converter in my '72 411. Wow what a difference. I now have a Code Z converter out of a Vanagon instead of the original Type 4 converter. The Code Z has a stall speed of 2450 to 2750 rpms verses the original at 1900-2000 rpms. I haven't seen all the specs, but I feel that the convertion ratio might be deeper as well. The exterior dimensions of the two converters (as well as the Code D converter used on early 2 liters) are identical, as are the splines and bores. This is an easy swap and well worth it. I am not worried about any extra heat build up as the car comes up to speed so much faster than before. I suspect that this makes for less slippage overal, and therefore less heat.

The rebuilders I checked with listed only one torque converter for all Type 4 engine applications from 1968 thru 1985? In actuality VW made at least 3 (and maybe 4) different converters, differing most notably in their stall speed. If you are interested in replacing your converter look for the Z stamped on the side of one of the three bosses where the converter mounts to the flex plate. The Z converter came standard with late 2.0 liter engines (Code NH Vanagon transmissions) and VW recommends that the Code D converter (used on early 2.0 L engines with Code NG transmissions) be replaced with a Code Z converter. I would extend this same recommendation to all earlier T4 converters, swap them without with a Z.

raygreenwood · Post by **raygreenwood** » Sun Jul 10, 2005 3:20 pm

Very cool info! nice to know. Thanks! I will be collecting an automatic soon to start to rebuild. Since mine are 4 speed....it may seem redundent...but there is the high possibility I may some day run out of parts to keep teh 4 speeds running. Ray

Longbeach412 · Post by **Longbeach412** » Tue Jul 12, 2005 9:27 am

Can anybody specify what year the vanagon started having the 2L motor and the Z converter? was it 85? Also would an H converter be identical in performance and fit?

wildthings · Post by **wildthings** » Sat Jul 23, 2005 7:42 pm

I believe that all air cooled Vanagons from 1980 onward used the Code Z converter. I have no idea if the Code H will fit or not, though it is similar in appearance. The Code H has a slightly higher stall range than the Z, 2500-2750 rpm's for the H verses 2450-2750 for the Z.

Longbeach412 · Post by **Longbeach412** » Mon Jul 25, 2005 6:56 am

Many thanks.

Longbeach412 · Post by **Longbeach412** » Thu Jul 28, 2005 4:09 pm

Well, it hasn't been that easy for me getting a Z So far!, all the rebuilders I contacted don't bother with the code. They ask what motor and year, look up a table and say yup we got it or we dont. Ask for the code and they know zilch. So can anyone steer me to a supplier/rebuilder who has the Z, or knows what it is! thanks

Guest · Post by **Guest** » Thu Jul 28, 2005 10:43 pm

If you can't find a junked Vanagon to steal the torque converter from go to your rebuilder or trany supply house and start opening boxes. The Z convertor can be identified by a "Z" stamped on the side of one of the three mounting lugs. Otherwise there is no visible external difference.

If you actually get to talk with the rebuilder himself and he doesn't have a "Z" converter remanufactured and ready to go, have him go through his cores and see if he has one he can build up for you.

Your present converter should have a letter stamped on one of the three bosses. As a matter of interest to the forum let us know what it is.

Longbeach412 · Post by **Longbeach412** » Tue Aug 02, 2005 11:48 am

Well, here is what I've done so far; My converter appears to be a D, and in all the shops I've found, I've located a K and an H, no Z. So, since the K stalls at 2200, and the H at 2500-2750, and the D is unknown but probably lower, I opted for the H as the best choice in absence of the Z. Any comments on this logic folks?

wildthings · Post by **wildthings** » Sat Sep 17, 2005 12:24 pm

In another thread I saw that you had gone with a K convertor, I had kind of hoped that you would go with an H so we would have known if it was a drop in replacement or not. My guess is that the H is the most available of the various Van/Vanagon convertors as my sources show it was used on all years of Waterboxer powered Vanagons. Might not fit the air-cooled though and at present I have no easy way to check it out, wish someone would try it and let us know.

Your old D convertor had a stall range of 1950 to 2250 rpm so if 2200 rpm is the lower end of the K convertor's range you should see noticable improvement. Best of luck with your project, hope everthing runs great.

Longbeach412 · Post by **Longbeach412** » Fri Sep 23, 2005 11:54 am

hey, if I had known that, I'd have had the H installed to see if it fits. Shoulda told me then since the guy had both to choose from. Anyways, what are creiteria for fitting/not fitting? is it purely physical or also running creiteria? I mean if it bolts on and rotates freely then it fits? As to the rest of the work, things are not going smooth at all, check my Dipstick posting. I just hope the car runs well enough soon to see how the converter works.