I’ve had a look through the archives but not really managed to find answers to a couple of questions, wondering if people can shed some light.

I’m looking at buying/building a gpN impreza ready for next year. I would be starting with a V5 or preferably V6 STi type R or RA. What I was wondering is why does the 4 door type RA seem to be used more than the 2 door type R in rallying? Surely the type R is lighter? What are the other differences?



Transmission questions: What seems to be the weakest link of the Type R/RA transmission?

Can the rear plated R180 diff be re-shimmed to adjust the pre-load, and as standard are the ramp angles set up to be 1way, 1.5way or 2way, can this be changed at all?



As I understand it, the centre diff provides a torque split biased towards the rear wheels (I presume through epicyclic gearing)? But DCCD is effectively a viscous LSD with adjustable preload enabling you to progressively lock the centre diff in five stages – resuling in an effective 50/50 torque split when fully locked?



What front diff is fitted in the V5/6 type R/RA? I’ve heard of sure-trac, is this a helical gear type LSD (torsen/ATB) or a viscous unit?



Thanks...

 

I think im right in saying that the type RA's are lighter than the Type r's.... this is probably why they are used more....

But if its going to be stripped out anyway i dont think there will be much at all in weight...

Bri