4EAT to 5MT swap on GC...how big a project?

Nigel Prodrive

Nigel Prodrive

Dirt surfer
what title says.

working on potential secret project. auto to manual swap, specifically interested in wiring issues. mechanical part don't scare me, but wiring maybe does....

 
Not much harder than a normal blown 5speed to non-blown 5speed swap.

You have to swap the rear end, easy. Tranny just bolts in place.

The worst part about the swap is the pedal box, just because it puts you working in a really uncomfortable position.

 
thanks lads. more or less what wuz anticipated. just would want to be sure that the speedo and cruise were still operable cuz this unnamed and still secret project would be a DD. seems key to have same-year bits for anything that needs electrix connecTors. pedal box/clutch swap goes MUCH easier with front seat out--no need to stand on your head while lying contorted on your back!

 
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Speedo will only be correct if you swap in a trans of the same final drive. I think all RS are 4.44. So unless you get a forester XT box you'll have to get a speedometer correction box.

For cruise I believe you need to swap the cruise computer.

Speaking of which, you probably want to swap the ECU too. It will work, but the auto computer is tuned slightly different with idle. It will piss you off driving an auto computer on a manual.

 
final drive on RS auto is 4.44

final drive on RS 5MT is 4.11

would be swapping in a 4.11 LSD anyway, so speedo problem should go away.

good point on swapping cruise unit and ECU, will start gathering nuts on those projects too.

 
Right, so if it has an auto now, the speedo won't be correct when you swap a 4.11 5mt into it.

Unless maybe you swap the gauge or something. I'm not actually sure what in there makes it read wrong when you swap gears.

 
If you swap the sensor, that might work. I think I had to do this when I did a similar swap. Also, I don't think it's the same on the newer ECUs, but on the Leggy SS one I had been using, there was a pin which if grounded would tell the ECU it was manual/auto ... I don't remember which.

 
You still ground a pin to tell its a 5speed. It's just the computer has a different idle map for the auto, and it's annoying driving with that on the 5speed.

I don't think it's a different VSS. I've swapped those around and never had an issue.

 
I would think it would be the sensor itself that adjusts accordingly. As long as you use the sensor from the MT, I would think that would work fine. I haven't noticed any problems with my speedo when the car was on the road.

Pedals were the worst part for me also ... the bolts just don't want to line up!

In terms of wiring, the harness ends are different. If you want plug and play when your done, try to snag a couple of those plug ends too. Otherwise, just splice into the harness from the trans. You can probably recycle the "park switch" wire for the clutch switch ... not sure what the difference in pins is on the MT ecu.

I know on the Leggy SS ecu I had been using, there was a pin that was used to determine if it was auto or manual. Grounded was one, ungrounded was the other.

EDIT: OOPS. I thought I hit back on the browser and the post disappeared ... apparently I posted it. Ignore the repeat info!
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