Basically fit one of these boxes to my Type R and ever since doing so find there is always some lock in the center diff even when set to fully open, which kind of annoys me as i'd like the option to have it fully open for a more rear end (car that is!) out option.

Has anyone with the above car or box found similar.

If someone is willing to find out then one way to check is to jack the rear up just enough to get the rear tyres airbourne and with the DCCD set to open (and in manual mode) put the car in gear and let the clutch out very slowly, if the DCCD is actually open the rear wheels will spin freely in the air.

If in my case the front tyres try to pull the car forwards then there is still some lock between the front and rear axles.

 

Not sure what you mean as even fully open diff, the My06 DCCD still sends approx 37% power to front wheels.

 

i have same box and agree with rickya , been told and read this but i have just fitted the latest version of neetronics controller but yet to drive it to see what it can do

 

Well in my Type R box when the DCCD was set to open if i lost traction at the back end (like jacking the rear wheels up) the car was basically rear wheel drive with all drive being sent to the back.

The center diff, when open, basically acts like that on a basic front wheel drive car (that doesnt have any lsd) in that if on the fwd car one tyre is on ice and one is on tarmac the side on the ice will spin away whilst the side on tarmac doesnt go anywhere.

 

Every subsequent version of the dccd became more 4wd than rwd in fully open. From classic to blobeye to hawkeye, they sent more & more power up front making them less snappy & a bit more tame. The Hawkeye got a few more percent power split to front in fully open than blobeye. This was apparently after development in conjunction with Tommi Makinen.

 

My understanding is it really doesnt matter about torque split, if the DCCD is truely open the above conditions for FWD would be the same.

If one end loses torque the other end will do too.

From what i learnt there is always some lock in the DCCD (MY06+) to prevent it from being truely open, the reason being is that there is now some amount of preload added to the plates in the center diff, makes the car less snappy but in my case has induced some understeer which cant be removed by setting the DCCD more open due to the preload.

 

There is preload in the clutch plates, even more so in the later 10 plate diffs, this was done to improve the consistency with age required of DCCD-A, not an issue with earlier manual DCCD setups.

Simon