Subaru Justy Gear Swap? - Fuel Economy, Hypermiling, EcoModding News and Forum

mtgeekman · 07-11-2009, 12:23 AM

Hello all I am looking for information on gear swaps for a 90 Subaru Justy.

What I have found so far is that the 87-88 transmission will bolt in and give me a bit better gearing but it still not all that great.

I also found this site on using a second gear in the place of a fifth to bring the ratios even lower. Modifying Gears for Taller Overdrive

though I don't have a friend with a shop anymore so I'm not sure that's an option at this point.

Any one know of options for Gear Swaps for Subaru Justy's?

mtgeekman · 07-11-2009, 03:06 AM

some information on the justy is on this Wikipedia page:

Subaru Justy - Wikipedia, the free encyclopedia

using those numbers with the stock tire size puts 60mph at about 3600 rpm with the second gen transmission and 3400 with the first gen transmission

( Subaru Justy Forum - Manual Gearbox Teardown/Interchange )
the place that pointed me to the site on using the second gear as a replacement 5th noted a drop from .675 to .590 which would get me to about 3150rpm at 60mph.

I would love to get that number down by another 500rpm at least. My plan is to go all out with mods. Including a boat tail, wheel skirts, undertray....

SVOboy · 07-11-2009, 11:34 PM

Yeah, those kei cars have some crazy gearing, so hopefully you can knock it down a bit. Looking forward to seeing what you can come up with

MetroMPG · 08-19-2009, 10:21 PM

We haven't seen many Justy owners around.

(They're not actually Kei cars, Ben - about the size of a Metro.)

Are there no dedicated Justy forums where you can get the specifics on regearing your final drive or 5th? That'd be my first plan.

mtgeekman · 08-20-2009, 12:33 AM

I have found one Justy forum that had some info on the gearing and even doing a swap. Though the only guy I know of that was actually going to try and do it ended up just swapping the tranny from the 87/88 into the newer car to lower the 4th and 5th gear. as for the final drive, I haven't seen any info on doing a swap for it.

I found that I can fit 165/65r14 tires on the car and I am hoping to get a set of potenza re92s for it unless there is a better lrr tire now?

Good news is I have the car running now, needed an exhaust valve and then it had a clogged injector. Still need to replace the distributor on it to fix a CEL code but its getting there.