The king

You probably do have a rear (though quite veak) VLSD.

arumdevil

Indeed I do. At some point I'd like to install a DCCD box and diffs into the legacy.

The king

Sounds like a true sleeper on tight tracks.

arumdevil

well it will be, I suppose it is now they're pretty good stock to be honest, but with a few mods can be improved a fair bit. Got the handling pretty much there just need a remap solution (like some of the classic imprezas, the ECUs aren't mappable from the factory....)

a DCCD and decent map would round it off nicely

johnfelstead

Most DCCD equiped vehicles DO NOT have suretrack diffs, the majority use Plated rear LSD's with either open or helical front LSD's.

The classic manual DCCD all use plated rear and either open or helical front diffs
MY05(widetrack blobeye) JDM STi with DCCD-A and Spec C uses a plated rear diff, front Helical diff.
MY06(hawkeye) JDM STi and Spec C uses a plated rear diff, Helical front diff.
MY07(hawkeye) JDM STi uses a Torsen rear diff, MY07 JDM STi Spec C uses a plated rear diff, both use helical front diff.

Most people dont know this, but on a car with a DCCD-A system (Auto mode available) when you touch the foot brake the centre diff fully unlocks, even when the car is in manual mode. So if you are braking, dont expect the car to react like it has a locked up transmition system or any more centre diff lock than fully open. This is done to allow the Sports ABS system to function. When you convert the car for Group N rallying, one of the mods is to cut the brake signal wire from the ABS system to the DCCD-A controller module to stop this happening.

johnfelstead

Nope, you could order your JDM STi to have a VC centre diff with suretrack front and rear LSD's.

johnfelstead

Nope, most manual DCCD equiped cars used a plated rear LSD with an open front diff, it was only a few such as the RA Ltd that used a front LSD, and that was a helical torque biasing item. If you are talking about mechanically locked centre diffs such as an air locker on a Land Rover, all 3 diffs can be whatever you fancy, you chose your diff strategy based on aplication.

TonyBurns

iTrader: (3)

John, your just god at these things (im still learning, badly but learning lol 8 nights didnt help either )

Anyway, apart from John (who is just correct and this post shows about the braking and freeing of the centre diff), looks like we are all correct and incorrect, just read post 6, and WOW is what you will say
(still its nothing like the Haldrex system on VW's, totally different, as you will find out by reading said below post )
http://forums.nasioc.com/forums/show....php?t=1281101

And one last interesting bit:-

http://www.awdwiki.com/article.html?inc=sub

Hope this sorts out all the confusion, lots to learn there from a very good post

Tony