anyone know what tranny they used and if its and how much stronger then the 7's auto tranny. also would the 20b tyranny bolt up to the 13b motor . are those tranny's built for speed ? thanks

 

it uses one thats similar to the fd rx7, it should bolt up.

 

The JC 13B & FD 13B auto box are the same box.

The JC 20B auto box is unique & wasn't used by any other Mazda. Nissan used the same 20B type box in there 4.2litre Patrol 4x4.

Unsure if its the same name in the USA.

 

cool thanks for the info. one more question. how much more power can the 20b auto tranny take compared to the fd. i would like a 5 spd but like my auto and hate traffic in new york. plus i wouldnt mind having 400 rwhp on a fd auto.

 

A heavily thrashed 20B box will fail even with standard 300hp 20B engines. Perhaps its the weight issue as the Cosmo is 1600kg compared to the Rx-7's 1200kg

RE-Amemiya has done a 20B box that is suppossed to be good for 750hp. At US$7000, its way to pricey.

Make sure the box has a high quality oil cooler that keeps it in check.

REgards

 

Isn't the Cosmo auto tranny electronically controlled? So how do you run the auto tranny with an aftermarket ecu?

 

Can't see the post where an aftermarket ECU was mentioned. In case its implied then its not hard with some electronics background to control the box electronically.

Disreagrding all the other inputs & sensors, you have 4 soleniods that activate each gear. Its a simple matter of switching 12V between each of them, then adding another 12V to the lock up soleniod when your in 3rd or 4th. etc etc

Over in Japan, modified versions of the factory ECU are a popular upgrade. Personally, I have an RE-Amemiya ECU upgrade in my JC Cosmo.

 

It was never sold in the USA, so the name is moot. (Unless that's what the Infiniti QX4 is. I am unaware of a 4.2l Nissan anything in the US, closest being the Infiniti Q41/Q45)

The transmission used in the FD is the JATCO JR401E. Mazda called this unit the R4A-EL, Nissan called it the RE4R01A. It was used in '92-up 929s, FDs, '89-up V6 MPVs, and '90-up 4x4 trucks, in Mazdas. Nissan used it in *ALL* '90-up RWD applications (in the US anyway). First seen in '88 4WD Pathfinders.

Note that there was a beefier version that Nissan called the RE4R03A. Used in 300ZX Turbo and Q45's starting in '90.

 

Perhaps this Nissan RE4R03A box is the same box.

The Nissan Patrol 4x4 is like a Toyota Landcruiser or (having just looked up the Nissan USA web site) a Nissan Armada SUV

Perhaps the box is shared with the 300ZX & Q45. Just know about the Patrol similarities. If our local auto tranny joint wants to re-build a 20B box, he gets his parts from the Nissan Patrol stockist. Could also get them direct from Mazda but JDM parts come here on the slow-boat