I have a 2004 rx8, which with the auto its a 4 speed. i was wondering if i could put in a six speed automatic which i believe came standard in 2006? will it match up?

 

It's an engine, transmission and electronics swap. It's cheaper to trade your care in and buy a 6 speed auto.

 

even to another auto?

 

yes. cheaper to trade up

 

The 4 speed auto had a 4 port engine (Low Power). The 6 speed auto had the same 6 port engine (High Power) as the manual trans models. There is more valves to actuate on the 6 port engine so the computer that controls the 6 speed auto wouldn't work on the 4 port engine. It would be looking for things that aren't there.

 

Just get a six speed auto rather than swapping transmissions. It will make life more easier.

 

From a failure to another failure. it's still a failure.

 

he didnt even try good sir

 

Im currently doing this having problems with the plug for the tcm wont fit the series 2 tcm not sure what to do could really use some help..

 

Majority of major components like that are not cross-series compatible. Nothing you can do except buy the correct stuff or abandon whatever it is youre attempting to do (hard to say what youre attempting with almost zero information)

 

me and my father have picked up a project and tried to swap a 2007 6port 6 speed AT into my 2004 4 port 4 speed AT.

most of the swap was straight forward only a couple things like the MAF sensor had to be Rewired, Had to order a custom driveshaft, the dash/gauge cluster, but this tcm has us stuck.
it drives like its stuck in 3rd or 4th gear

 

A 4 port ECU can't drive a 6 port engine, nor a 6 speed trans. Which ECU are you using. Swapping ECUs requires swapping the entirety of the wiring harness, they're not interchangeable.

 

shelldudue went through this years ago. he started with a 4port 4 speed, then went turbo, then swapped to a 6port 6spd m/t. his car spent more time at speed 1 (old rotary shop) and could have bought 2 m/t 8s easily or rew swapped his when by time it was done lol. its possible but not cheap or easy

 

If memory serves me right, things in our 8's changed slightly from the 2004-2005 and 2006-2008 model years. Electronics might have troubles with communication due to some added tech in the 2006-2008 models. Extra wires and stuff which means plugs/pigtails also different and some modules might not play nice.

You might just need to get the rest of the body harnesses and swap those over.

You shouldnt have needed a custom drive shaft, that shouldve been interchangeable with any Rx8 drive shaft. The gauge cluster also should be interchangeable to some degree. Something is mismatched, likely your wiring harness and jumping between mid-generation updates add to the problems youre running into.

 

iirc autos have aluminum drive shafts and m/t have cf

 

I thought autos had a type of steel drive shaft, aluminum was a mazda motorsports item i think. manuals had the carbon fiber yes

 

could be i never really looked too much into autos

 

So the 6AT might have a different drive shaft from what a little research has found. 4AT shaft may work with 5MT and 6MT, but might have a slightly different yolk on the 6AT.

I could see how a 6AT would be good for anyone who may have some disability or prior injury which may make it difficult to actuate a clutch pedal, but I do still believe its cheaper to just buy a 6AT 2006-2008 series 1 Rx8 than to try and convert a 4AT 2004-2005.