Dccd box without ecu.
 

After finding out that an r180 won't match my box :brickwall just curious to see what torque split would be if you used a type r dccd box without the ecu wired up to the car. Can this be done?

I had a P1 gearbox, rear diff & type r dccd fitted to my old classic with no ecu and it defaults to 63/37 or 60/40 whatever the rear most bias was :thumb:

67R/33 F, but the dccd set up is allied to a 1:1 transfer box so you need to match front and rear diffs.

P1 rear diff also works as it's 4.44 ( basically an Sti V set up) and the P1 used a 1:1 transfer box unlike the UK cars transfer boxes which are 1.1:1.

I have had the 5 speed dccd centre diff in my p1 and now a whole 6 speed box ( for which I had to change my rear diff to an R180 3.9), and both were wired up, but the diff spends 99% of the time wide open anyway

I have the Jdm close ratio box, so that means it has the 1:1 transfer box ratio? Think ill take the backplate of my current diff n just check that it isn't a 4.44 which the type r sti uses. When I had a quick look and span the input and the output it turns over 4 times on the input so it's either a 4.1 or a 4.4. As for the split, 67r and 33f, that's not bad. But having it as that all the time without being wired up. Would that damage it in any way?

I ran mine un wired for over a year and it was fine :)

This probably won't display too well - but it goes model name first, then version number - 3 /4 or whatever, then the gearbox code, which is on a sticker on the box, then follows the ratios up to 3.416 (reverse) then the transfer box ratio, which in the first example below is 1:1, next you see the rear diff ratio, plus finally additional comments on the set up.

Soif you have an STI Type Version 3 then originally you would have had a 4.44 rear diff and 1:1 transfer ratios.


JDM Impreza WRX & WRX STi Ver.III/IV MY97-98 TY752VBCAA 3.166 1.882 1.296 0.972 0.738 3.416 1.000 4.444 Viscous (4kgf) Open Double-cone 3rd synchro added (all turbo Impreza) (also STi V-Limited Ver.III MY97)

JDM Impreza WRX RA MY97-98 TY752VB5BA 3.083 2.062 1.545 1.151 0.825 3.416 1.000 4.444 Viscous (4kgf) Open Widened 1st,2nd,3rd gears (EJ20K models only)
(also WRX R V-Limited MY98)

JDM Impreza WRX STi R & RA Ver.III/IV MY97-98 TY752VB5CA 3.083 2.062 1.545 1.151 0.825 3.416 1.000 4.444 DCCD (35:65) Open Widened 1st,2nd,3rd gears (EJ20K models only)
(also STi Type R V-Limited Ver.IV MY98)

Re running it open permanently - no problem. it's designed to fail open and I have also run mine fully open for nearly ten years now apart from the occasional slight locking in really greasy conditions