BBQdDude

Hello, Is it possible to replace a 4 speed auto tranny with a 6 speed auto tranny. If so any supporting parts needed? Thanks, Brian

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G-Gray dude

why would you do that, dude? keep this in mind.
4 speed has more torque end then the 6 speed -----> 164 tq vs 159
maybe the horsepower is the lower end. i mean it's not gonna make it any faster than it is rite now. the difference i've seen between my 6 speed auto and 4 speed auto in 1/4 mile and 0-60 is only .1 - .2 difference in seconds. plus you might end up shelling out tons of money. cuz i think you need 6 speed engine, ECU, wiring harness, new tacho for 6 speed AT. i think it's such a hassle to go through all that, buddy. like i said its is very possible to do a swap. you just need patience and money. that's all.

BBQdDude

Bummer.

Yeah I searched on this to see what gains I might get. However I could find nothing on 4 port engine and 4 speed tranny to 4 port engine 6 speed tranny (as most 6 port engines use 6 speed trannys when talking RX-8).

I was looking at it from the angle more gears to get to say 75 miles per hour would give me a quicker time to hit that speed. I was thinking if it took three gears instead of two then those three gears can hit 2500 RPMs quicker than winding through 2nd gear which would, in my cloudy thinking, get me to 75MPH a little quicker.

Probably flawed thinking but if all it took was the tranny I would have proceeded.

Guess I should stay to designing computer networks, it hurts my head less (the devil you know ) .

Take care,

Brian

JTtheDude

You would at least need a 6spd ECU to control the additional 2 gears, but even if you got one the ECU is going to be setup for the 6port engine and I don't know of a way to program it for a 4port. Unless you have a ton of cash for the swap it's probably not worth it. If I were you I would look at getting either the Feed final drive or getting a new torque converter to get better launch.

G-Gray dude

it's hard to source a custom new torque converter. the only place i know is level 10. but that place requires you to send them your core.

JTtheDude

I agree that the torque converter would be pretty difficult to find, the Feed final drive is probably more suitable. I also didn't know level 10 needed your core, good to know!

mdw1000

I remember researching this myself a little bit aways back. The conclusion was it would just be better to trade the car in for one with the 6AT than try to do a custom swap. The costs would be astronomical to do the swap, if I remember correctly. I think it was Paul from Mazmart that poo-pooed the idea, and he is a very knowledgeable guy.

BBQdDude

Cool, thanks for all the input it is appreciated.

Not a big deal. If it was just the tranny I would do it in a heart beat.

Oh well .

Take care,

Brian