Whats best, DCCD or 20kg centre?
- cruzingbrumby
- Junior Member
- Posts: 87
- Joined: Mon Nov 14, 2005 10:00 am
- Location: NSW
Whats best, DCCD or 20kg centre?
As the title say looking at upgrading the gearbox with a front lsd and a good center, so would be 1.5 way front, and either dccd center or a 20kg, what would be better for mixed onroad/offroad use?
- cruzingbrumby
- Junior Member
- Posts: 87
- Joined: Mon Nov 14, 2005 10:00 am
- Location: NSW
it all depends on everything!!!
offroad, 20kg centre would probably give you more lock, ive seen rallycars with them drive happily with broken driveshafts. dccd's dont seem to lock up quite as much, but chances are the ones ive seen/played with have just been tired
onroad, 20kg centres bind up a lot, groan and creak and chirp tures pulling into parking spots, dccd you have the option to open them up and are a lot more civilised!
the front lsd will be interesting too, assuming you have plated rear as well... whatever you do, its going to be binding up pulling in and out of parking spots, and making lovely noises.
id probably just go the 20kg for an on/offroad car, just makes it simpler...
offroad, 20kg centre would probably give you more lock, ive seen rallycars with them drive happily with broken driveshafts. dccd's dont seem to lock up quite as much, but chances are the ones ive seen/played with have just been tired
onroad, 20kg centres bind up a lot, groan and creak and chirp tures pulling into parking spots, dccd you have the option to open them up and are a lot more civilised!
the front lsd will be interesting too, assuming you have plated rear as well... whatever you do, its going to be binding up pulling in and out of parking spots, and making lovely noises.
id probably just go the 20kg for an on/offroad car, just makes it simpler...

- cruzingbrumby
- Junior Member
- Posts: 87
- Joined: Mon Nov 14, 2005 10:00 am
- Location: NSW
- cruzingbrumby
- Junior Member
- Posts: 87
- Joined: Mon Nov 14, 2005 10:00 am
- Location: NSW
DCCDs are rubbish for off road use - put them under any sort of prolonged strain and they will start to slip like buggery. They can be rebuilt but will cost about $1500 in parts alone.
By the way I'm in the market for a DCCD for my road car - care to pass on the details of where you can get one for $500
Ok so I'm just kidding about them. A DCCD is a just a clutched LSD that you can adjust from fully locked to fully open. I don't see any reason why they wouldn't be any good offroad. When they are fully locked they groan like buggery doing tight manouevres, just like a 20kg does.
As far as installing them in a non DCCD box - you need to drill a hole in the top of the box, feed the wires through and silicon them in. You also need to be aware of the following, quoted from dtrally on the RSLIBERTYCLUB website :
We had to use the entire rear case. That's not to say it's impossible to use a standard rear case, just that there are some differences. The top cover has the wiring hole, the rear housing has the locator and the output spline is different (single spline only, where VCD has a double spline) It also appears impossible to use 1.1:1 drop gears with 5 speed DCCD (I tried that with your car Ken, before going to a 3.9 rear diff) Short answer, if you want to make a 5 speed into dccd then use everything from the split case back.
Also read up ere on what people think of DCCDs and a bit of explanation of how the wqork and what effect they have : http://www.rslibertyclub.org/forums/sho ... post768311
I am serious about buying the DCCD centre if you decide you don't want to go that way.
By the way I'm in the market for a DCCD for my road car - care to pass on the details of where you can get one for $500

Ok so I'm just kidding about them. A DCCD is a just a clutched LSD that you can adjust from fully locked to fully open. I don't see any reason why they wouldn't be any good offroad. When they are fully locked they groan like buggery doing tight manouevres, just like a 20kg does.
As far as installing them in a non DCCD box - you need to drill a hole in the top of the box, feed the wires through and silicon them in. You also need to be aware of the following, quoted from dtrally on the RSLIBERTYCLUB website :
We had to use the entire rear case. That's not to say it's impossible to use a standard rear case, just that there are some differences. The top cover has the wiring hole, the rear housing has the locator and the output spline is different (single spline only, where VCD has a double spline) It also appears impossible to use 1.1:1 drop gears with 5 speed DCCD (I tried that with your car Ken, before going to a 3.9 rear diff) Short answer, if you want to make a 5 speed into dccd then use everything from the split case back.
Also read up ere on what people think of DCCDs and a bit of explanation of how the wqork and what effect they have : http://www.rslibertyclub.org/forums/sho ... post768311
I am serious about buying the DCCD centre if you decide you don't want to go that way.
- discopotato03
- Senior Member
- Posts: 2134
- Joined: Sun Mar 18, 2007 9:29 am
- Location: Sydney
Neither , IMO the best dual purpose is an open center diff with a mechanical lock - dual mode for dual purposes .
You also need to think hard about the LSD in the front , when they do limit slip they make the steering quite heavy and want to understeer on hard surfaces .
The better European front drive cars use a Torson diff center and I think some have been made for the Subaru gearbox .
Otherwise a plate LSD with low pre load is what tends to work in mild rally spec WRX's .
A .
You also need to think hard about the LSD in the front , when they do limit slip they make the steering quite heavy and want to understeer on hard surfaces .
The better European front drive cars use a Torson diff center and I think some have been made for the Subaru gearbox .
Otherwise a plate LSD with low pre load is what tends to work in mild rally spec WRX's .
A .
- twilightprotege
- Junior Member
- Posts: 480
- Joined: Sun Mar 16, 2008 7:56 pm
- Location: Brisbane
i want to get a 20kg centre and i'd love a torsen front diff for my suby. i have one in my mazda astina and it's flippen great and that's putting it mildly! absolutely a pleasure to drive slow (totally like stock), and when you go hard in to the corner, the harder you turn and faster you go, the more and more it grips! on the drag strip it's great too. awesome all round diff imo
mind you i'm going to just try my car with the stocko 4kg centre diff and a front lsd and see how that goes before i upgrade the centre
mind you i'm going to just try my car with the stocko 4kg centre diff and a front lsd and see how that goes before i upgrade the centre
06 Foz, 2" lift, 225/70/16 tyres
- discopotato03
- Senior Member
- Posts: 2134
- Joined: Sun Mar 18, 2007 9:29 am
- Location: Sydney
I think from memory the std WRX center diff is preloaded at 8 KG isn't it ? Probably a fair compromise if it is .
Gareth in Victoria (BratGeebra) knew of some local mob making Torsens for most apps inc Subaru . It would pay you to do a bit of searching about Torsons as they come in a type 1/2/3 for different driveline locations/conditions . Also he had at one stage a Torsen center diff but for some reason it required straight cut transfer gears (in the back) and they howl a bit .
Not cheap mods playing Subaru gearboxes so need to be seriously bent and flush to make it happen .
Also a feller in NZ claims he has access to locking center diff type EJ boxes and you can read about them at USMB .
Money , you can't take it with you so may as well drive it there !
A .
Gareth in Victoria (BratGeebra) knew of some local mob making Torsens for most apps inc Subaru . It would pay you to do a bit of searching about Torsons as they come in a type 1/2/3 for different driveline locations/conditions . Also he had at one stage a Torsen center diff but for some reason it required straight cut transfer gears (in the back) and they howl a bit .
Not cheap mods playing Subaru gearboxes so need to be seriously bent and flush to make it happen .
Also a feller in NZ claims he has access to locking center diff type EJ boxes and you can read about them at USMB .
Money , you can't take it with you so may as well drive it there !
A .