P5 5th gear swap

^thanks

niky said:

Not in here a lot anymore, but just saw this. Look up the Malaysian guy with the turbocharged Ford Tierra. KasmanK, I think was his handle. They only sold the FS-DE there with the four-speed automatic, so when he turbocharged his car, he swapped the box out completely for a 626 box. Worked just fine for him. Gives you the longer fifth and a longer final drive, so all gears are effectively longer.

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I've got a list of all gear ratios in all Mazda boxes on another computer; I'll post ASAP. IIRC, the only 5th I could find in ALL trans codes was a .717 instead of the stock P5's .755 - it isn't a huge difference. I can't recall the final drive though. I'd be leery of changing the FD only because you'd have to stay in gear longer and rev higher since the taller gears effectively reduces your torque and works the engine a little harder. I only want 5th taller. But it's hard to get an idea of how big the change would be until I find that FD info! I guess if it's only a slight change...

So the MX6 has the best gearing for low revs, but can I just head out to the junk yard and take 5th gear right out of the tranny and swap it directly into my Protege5? I'm planning for a clutch, motor mounts, and inserts soon.

Hello guys,
I did the 5th gear swap with a 2001 626 and I have a problem. The new 5th gives me the drop I hoped for 500rpms over the stock, but when I am in 5th the data logger shows a huge load added to the engine and I can’t accelerate nor can I hold a speed without a huge load on the engine and bad gas millage. 24mpg at 3k rpms. 4th gear yields 30mpg at 3k rpms. I am hopping that it is only because I am running with no boost right now because my AFR in boost is so bad.

ZealoustheEnder said:

Hello guys,
I did the 5th gear swap with a 2001 626 and I have a problem. The new 5th gives me the drop I hoped for 500rpms over the stock, but when I am in 5th the data logger shows a huge load added to the engine and I can*t accelerate nor can I hold a speed without a huge load on the engine and bad gas millage. 24mpg at 3k rpms. 4th gear yields 30mpg at 3k rpms. I am hopping that it is only because I am running with no boost right now because my AFR in boost is so bad.

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I know this is a super late reply and you most likely already got this figured out, but I wanted to chime in for anyone who might search about this down the road:
I think I read something about the speed sensor needing to be swapped from the original trans.
that said, Im not sure if that is your problem as the 626 4cyl is the same engine as in the protege's with a 2.0l so it should react the exact same as it would in a 4cyl 626.