I've found a rebuilt one at a decent price with an R180 plated diff. Problem is the box has a 3.9 diff in it and the R180 is a 4.44. So firstly, where can I find a 3.9 CWP for an R180?

Secondly, what do I need to fit this lot to my car? The box, the rear diff, a DCCD controller, a toggle wheel, is there anything else? DCCD clocks I guess, although not sure how they wire in with an aftermarket controller.

Also, I'm tempted because of the price, but it is a track/hillclimb car (and I'd like to transition it into a Gymkhana car) so am I on a hiding to nothing fitting the 5 speed and better off just waiting til I can buy a six speed?

 

That must be an early DCCD gearbox from 95-96? http://www.gearhack.com/myink/ViewPa...ission%20Chart

You can find 3.9 R180 diffs in Newage JDM STI's but they don't seem to come up for sale that often.

I think you can run it without the DCCD clocks and use an aftermarket controller but I'm not sure about that.

You should remember that the 6 speed is about 30 kg heavier so depending on your power level you could just as well use the 5 speed and not adding 30 kg extra in the wrong end of the car. The 5 speeds (at least the JDM 5 speed DCCD boxes) feel nicer to shift than the 6 speeds.

I have fitted a 6 speed Spec C gearbox in mine but I'd rather have kept the 5 speed but at 400+ bhp it wouldn't have lasted long.

 

It's only running something like 280 at the moment and once I add the yellows and a front mount and get the ESL fitted and mapped I'd be shocked if it was any more than 330 to be honest.

 

No way I'd use a 6 speed at that level, more weight means you have to compensate with more power. But the later 5 speeds for the phase II engine are supposed to be a little bit stronger though.

 

It's worth considering then. Just need to figure out this diff thing. I don't want to spend 400 quid on a JDM R180 just for the cwp out of it!

I wonder if the front diff in the box could be swapped to a 4.44 easier/cheaper?

 

I don't know about that but it can't be that hard to find a nice condition 5 speed later DCCD gearbox in the UK surely? That would be the easiest solution if you already have a good R180. I have the original 55000 km one in my garage but I'm keeping it in case I decide to go back to stock one day.

 

I don't have any of it yet. Guy is selling the box and the R180 together.

 

A bit strange selling them as an unmatched set. Be aware that many R180 are worn in the clutch pack assembly and don't lock the way they should. Both my original 4.44 R180 and the 3.9 R180 I got with the 6 speed had a low preload so I had to rebuild them. But I think there are Suretrac R180's in 3.9 as well.

 

Well apparently this R180 is a plated motorsport diff? I don't know much about them myself tbh.

 

STI used to sell a kit with different ramp angles so it could be that or a different aftermarket clutch pack assembly. Or just an OEM diff rebuilt to proper preload.

Here's a thread on rebuilding the rear diff https://forums.nasioc.com/forums/sho....php?t=2726130

 

Didn't really want the extra expense but I have seen an R180 3.9 Suretrac diff. Say I got this to match the gearbox, provided it's a 1:1 drop gear obviously, I could always ell the 4.44 diff. But if I get this setup, can I still use my WRX hubs and driveshafts I do I need some newage STI hubs and driveshafts?

 

You need R180 hubs and driveshafts but they can also be found in classic Type R's and later RA's.