sti 6mt converts... how many sti r180 rear diffs are there?

[Benjamin Tang]

i've been under the misconception that the r180 rear diff only came in the sti ver.7 and up. my friend overseas says it's not so because he just worked on a gc8 ver.5 RA sti and it also has a r180 rear diff.

what is the FD? is this r180 rear diff from the ver.5 something i can use when converting over to an sti 6mt on my wrx, and still be able to keep everything else out back?

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[AZScoobie]

Ben. The R180 was used in GC8 cars. The Type RA's came with R180's mainly. Others had R160's. The rule of thumb you can use is that if the car had DCCD control on the Center diff it came with an R180 rear diff.

You can use any of he R160's or R180 diffs in your car as long as the Correct ring and pinion is installed. For A 6mt swap you can use either one...

Clark

[gpatmac]

The US STI has 180 as well, right?

I kept the R160, and although I've decided that with how much (little) hp/tq I'm making I'm probably not at risk of damagine my rear diff/spiders, my drag racing days are pretty much over.

We don't have an AWD dyno here, but I'm guessing I'm 340-350hp at the crank. (12.8 @ 104)

[AZScoobie]

Yes. US STI has R180. Alot of people are using the R160 wih the 6mt at your power level and above without issue. In rally the R160 seems to fail and the R180 is a reqiurement. Shock is what kills it.

Clark

[Soon2Bgreat]

the final drive on most gc8 r180's will be 4.44. Some may have 4.11 but either way it won't be 3.9. It is much easier to use a gd one as it has the right fd, imo.

Ben if your doing this to a wrx i don't think it would really be cheaper to get a gc one as you'd have to change the fd, not to mention they're not much cheaper than gd ones. Keep in mind also you'd have to use the gd axles as the gc ones are too short. If you're going with the r180 i suggest just getting a gd one, unless you find a great deal on a gc one (free maybe, lol.)

Good luck.

[garface]

Your ratio won't match and you'll still need different axles. You'll basically have to change the same things that you are changing if you use the GD one, except you'll have to take the extra step of changing the ring and pinion.

[Benjamin Tang]

ugh... i was hoping to avoid changing the drive axles and hubs, but still be able to use an r180 for durability. scratch that plan

another bonehead question... the rear 2-pot brakes from the ver.5 RA... will they fit gdb hubs?

[garface]

They should fit GC hubs. I think you can do a hybrid axle to get around that problem. Use the r180 inboard and WRX outboard.

pm'd you

[Benjamin Tang]

ugh... (past honda experience in my dark, shady past ) makes me shy away from hybrid one-off axles.

for those of u who have converted to the r180 rear on your wrx... what have u done with the temp probe/sensor/thingy?

[garface]

I'd say plug it or run an aftermarket tranny temp gauge into it. That would be pretty cool.

[NicGordon]

Originally posted by Benjamin Tang
another bonehead question... the rear 2-pot brakes from the ver.5 RA... will they fit gdb hubs?

As far as I know, they won't. The GC8 (v6 and sooner) STi used the Subaru 2-pots, the GDB (v7 and later) STi used Brembo 2-pots. From what I've been told the Subaru 2-pot and Brembo 2-pot use different backing plates. So the only way Subaru 2-pots would fit on a GDB would be to use the GC8 2-pot backing plate. Though, I could be talking out my ass.

-Nic