I've not drived a car with dccd before so I'm not sure what to expect, I have fitted a dccdcpro auto controller which you can also run in manual. I don't have a dash readout just a diode that gets brighter as the amount of lock is increased.

In auto it sorts in self out but can be adjusted, it still has to run just about full lock in auto to stop the rears spinning.

My question is at what setting does your car stop spinning the rear wheels. I have found a steep hill with a few tight bends, bit like harewood or Barbon hill climb, and unless I run at nearly full lock it just stands there and lights the rear tyres up in second gear.

I changed the diff from 3.9 to 4.1 could it be that the ratio is to low now? Car is a 93 type RA with approx 330/300 - so nothing silly power wise.

 

That's a silly question as there isn't a single answer. Will depend entirely on how much torque you are putting through the drivetrain, how much grip the suspension and tyres generate, whether you're accelerating in a straight line or cornering, etc. etc. etc.

Eh? Are you saying that you have changed the final drive on both diffs to 4.1 (and have 1:1 dropgears) or are you saying that you have swapped the rear diff from 3.9 to 4.1 without changing the front, and therefore have mismatched front and rear final drives? If you have, it's not remotely surprising your car can't generate proper traction under power. Would also not be particularly surprising if your DCCD decides to overheat/wear prematurely/break quite quickly under these circumstances.

 

Sorry bit short on info

The 92/93 RA runs 4.1 as standard, the V2 STi RA runs 3.9, which is the box I bought. I swapped out the 3.9 diff from the box and put my 4.1 in so yes the diffs are the same F&R - 4.1.

It just seems very rear biased and I wondered if this was normal.

 

It's supposed to be rear-biased. 66:33 (or so) rearward instead of 50:50 on a viscous car. With the limited slip section of the DCCD unlocked it will be keen to slip its rears when the diff is unlocked.

It's also an open question as to what sort of state the plates in your DCCD unit are in. If they're heavily worn then it won't transfer torque as intended.

 

Cheers for the reply, much appreciated. I think I understand a bit more now, just spent 6 hours reading up and trying to get my head round it all. Maybe I need to play with the settings for a few days and see how I get on.

The other thing that worries me is the drop gears, with the front diff being 3.9 before I swapped it out are the drop gears 1:1.1 ? or 1.1

Assuming the drop gears are correct I'll give a few more days and if I can't get use to it I'll put my old centre diff in.

 

1:1 in RAs
http://spda-online.ca/modules/tinyco...ite/tc_28.html
perhaps you're lifting a rear or front wheel on the inside of the tight uphill hairpins - unless you have tight lsds you'll spin away all your torque