Anyone in Florida Capable of Building a Great Auto Tranny?

[IJ.]

Blackfin: They don't have a website and this is an Australian phone number so will need the 0011 61 stuff>> Ask for Michael

M V Automatics
1 Stirling Rd Blackwood
5051

(08) 8370 0430

Yes the cooler at the back is the Trans one (no room at the front of the car)

 

[Blackfin]

IJ: Thanks, I will give Michael a call. Also thanks for paving much of the way.

 

[foreverpsycotic]

my friend is pushing 600hp 650tq through a MKIV auto that was built by a place in mass. he blew up a BL. i can get the # if you are interested.

 

[Ckanderson]

is there a thread explaining out trannys on here newhere

http://en.wikipedia.org/wiki/Transgender

 

[tte]

my friend is pushing 600hp 650tq through a MKIV auto that was built by a place in mass. he blew up a BL. i can get the # if you are interested.

Did he have a mk4 auto in a Mk3 car or mk4 car?

I want to either buy another a340 auto tran and build that or if the mk4 auto fits in our car, I will buy the mk4 auto and use that.


cheers,
Roy

 

[Blackfin]

Did he have a mk4 auto in a Mk3 car or mk4 car?

I want to either buy another a340 auto tran and build that or if the mk4 auto fits in our car, I will buy the mk4 auto and use that.


cheers,
Roy

I am thinking the same way.

You would think that if a MK4 a341 could be swapped into a 7M MK3 without too much challenge someone would have done it by now. I have searched and found some that considered it but no one seems to have actually done it. Considering the cost to build the a340 series, it would seem reasonable to begin with the better tranny if possible even if it meant using an aftermarket tranny computer. When I contact the various builders, I plan to find out about their opinion concerning this.

 

[jdub]

I'm thinking the body tunnel will have to be enlarged to accommodate the bell housing.
Not to mention a different spline/length drive shaft...plus fab'ing a rear tranny mount.

 

[Blackfin]

Just to demonstrate my ignorance; I believe the transmissions differ in the ways listed below. Please correct me where wrong and append.

• a341 bell housing is bigger than the a340 bell housing to fit a larger torque convertor. It should still bolt up to the 7M but there may be clearance issues with the MK3 tunnel.
• a341 is fully electronically controlled. On the 7M a cable manually controls line pressure. Shift points on both are electronically controlled. The transmission computers are not interchangeable. This would seem to neccesitate use of an aftermarket or MK4 transmission computer.
• Speedometer on the MK4 is electonically contolled by signal from the a341. The MK3 speedometer is cable controlled.
• The section of the a341 transmission by the output shaft may be longer or shorter thus requiring a different length driveshaft.
• The a341 torque convertor has a different number of splines and is not interchangeable with the 7m a340.
• Don't know if the a341 torque convertor input shaft will match up to a 7M.
• The mid-section or pan of the a341 may be a little taller. Otherwise they are similar.
• The a341 has more clutch plates.
• The valve bodies are different.

If the a341 with a341 torque computer will fit the 7M and the differences in bell housings don't require significant work to the tunnel, then the major challenge in my opinion would be electronic contol of the transmission and communication to the speedometer and other systems if needed.

Disclaimer: I know almost nothing about transmisssions. Do not rely on any information in this post.

 

[Blackfin]

Jdub:

by "different spline/length drive shaft" are you referring to the output shaft only? Wouldn't that be fairly easy to ovecome with a custom drive shaft allowing fitment to the a341 output yoke.

 

[foreverpsycotic]

Did he have a mk4 auto in a Mk3 car or mk4 car?

I want to either buy another a340 auto tran and build that or if the mk4 auto fits in our car, I will buy the mk4 auto and use that.


cheers,
Roy

It was a built MKIV trans in a MKIV. They should be able to do the same with a MKIII. IIRC, the owner built one for his MKIII. I think it was Best Transmissions or something like that.

 

[jdub]

Jdub:

by "different spline/length drive shaft" are you referring to the output shaft only? Wouldn't that be fairly easy to ovecome with a custom drive shaft allowing fitment to the a341 output yoke.

Yep...plus what you mentioned about the input to the TC. A SSV4 should be able to control the A341. Inputs to the ECU (speed sensor #1 & 2) and the speedo will have to be modified to work...sounds like it would be stand alone time, an AEM or Motec. This would be a lot of custom work

 

[Blackfin]

Yep...plus what you mentioned about the input to the TC. A SSV4 should be able to control the A341. Inputs to the ECU (speed sensor #1 & 2) and the speedo will have to be modified to work...sounds like it would be stand alone time, an AEM or Motec. This would be a lot of custom work

I have been reviewing the "How to make a a340 last" thread on SF

http://www.supraforums.com/forum/showthread.php?t=267655

as well as the "Transmission for the 2JZ/MA7 hybrid conversion" from supras.nl

http://www.supras.nl/index.php?option=com_content&task=view&id=35&Itemid=52

I am not ready to conclude whether it is feasible to use the 2JZ-GTE a340e with the 7M-GTE / MK3 but at least I know a little more. There is a lot of info here and anyone thinking about improving the a340 should certainly review. Plan on spending a half day to properly digest. Unfortunately, I can find little follow up to either write-up. I really would like to know how the hybrid tranny performed.

From the supras .nl write up I find that it is possible to install the 7M GTE a340 extension housing and output shaft into the 2JZ-GTE a340 auto. Doing this preserves the gear driven speedometer, the electronic ABS signal and the transmission mount for the MK3 7M-GTE. Unforunately, the 7 disk clutch of the 2JZ-GTE a340 (versus 6 disk for the 7m-GTE) was lost without custom work, which was not done. However, the 5 (versus 4) direct disk of the 2JZ-GTE transmisison is preserved.

Based on the above, it appears that the switch to the 7M-GTE output shaft and extension housing allows you to keep the inputs to the ABS and speedometer and also eliminates need to change driveshafts. Unfortunately, some of the benefits of the 2JZ-GTE a340, specifically the additional forward clutch, may be lost.

To use the 2JZ-GTE a340, it will also be necessary to use the 7M-GTE bell housing to bolt up to the 7M-GTE engine. The bolt patterns and starter location are different for each engine. Since both a340's share the same bolt pattern to the bell housing, this is a simple bolt-on swap. What Is not addressed, since this write-up was for installing a 2JZ in a MK3 is whether the 7M-GTE torque convertor will fit into the 2JZ-GTE a340 or what is required to make it fit. This needs to be looked into further.

 

[IJ.]

BF: The 7m uses a 26 spline Converter and Jz 340 is I think 28 nut it's a 6 bolt mount that should bolt to a 7M driveplate you'd just need to check the pilot diameter to make sure it will fit into the 7M crank.

 

[Blackfin]

IJ:

Sorry, my backgound is not mechanics. I don't fully understand. Are you saying all is needed is the 2JZ torque convertor? It should bolt up to the 7M driveplate. Will the 2JZ torque convertor fit into the 7M bellhousing? What is "pilot diameter"?

 

[IJ.]

BF: As far as I can tell the JZ converters are the same diameter as the 7M ones the main difference being the splines.

The Pilot is the nose on the Converter that fits into the back of the crank, I'm not sure if there's a difference.

Main problem running the JZ trans is the Electronic Line pressure as ours is cable based then you'd need to sort out a Speed Signal/Speedo Cable drive as Cruise Control and the ECT rely on these.

 

[Blackfin]

Thanks,

well replacement of the extension housing and output shaft should resolve the speedo and ABS signals. Do you think an AEM, MK4 tranny computer or an aftermarket tranny computer such as the suprastick would be able to handle the line pressure and remaining functions? I don't care too much about the cruise control but would like to keep the ECT or at least override it to "sport" mode.

 

[IJ.]

The SSv4 won't work as it's only for 2 solenoid Trannys.

Why are you considering the JZ trans again?

 

[Blackfin]

The SSv4 won't work as it's only for 2 solenoid Trannys.

Why are you considering the JZ trans again?

Two reasons:

• it should be stronger due to the additonal forward and direct clutches (whatever they are). Although, replacement of the extension housing may require loss of the additional forward clutch anyway
• There is greater support for anything MK4. Boost logic will build it.

 

[IJ.]

MV Squeezes additional clutches in during a build.

I'd go with the place JDub used if they're local to you it's not rocket science.

How much power are you planning to put through it?

 

[Blackfin]

MV Squeezes additional clutches in during a build.

I'd go with the place JDub used if they're local to you it's not rocket science.

How much power are you planning to put through it?

700rwhp is design power