AWD 12kg Centre Diff LSD

thunder039 said:
i would still rather have a rear locker/lsd in the rear then go to the effort of putting in a lsd in the front. the lsd in the front would be my last mod
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Well its a big mod to do. Time consuming, thats the issue.

A rear one is easy to do and very effective in helping offroad.
 
I don't know what the 5 speed DCCD's are like, but it is certainly worth investigating. I have not touched my rear plated diff since installing it, although eventually it will wear out. Everything does. But I have given it a full workout and so far, so good. Like others I think that when including the $$$ issue, the rear diff is the first thing to look at, then work your way forward.
 
d_generate said:
Exactly why I sold my new STI plated diff and put the OBX in, also made $1,050 on the deal :raz: and can run ABS and any oil I want, also no clunking every time you go around a corner, you'd never know the OBX was in there.
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Whats an OBX?

Rally said:
Like others I think that when including the $$$ issue, the rear diff is the first thing to look at, then work your way forward.
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Thats what I'm starting to think. If/when I do the centre I'd be wanting to do l-series LR plus front LSD all at the same time...easier & cheaper to do the rear first...gives more bang for your buck!
 
Nachaluva said:
Thats what I'm starting to think. If/when I do the centre I'd be wanting to do l-series LR plus front LSD all at the same time...easier & cheaper to do the rear first...gives more bang for your buck!
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Exactly. For a good ultimate box it's basically the cost of a first gen foz (5k or so). This would be a reconditioned one too and I see that if your replacing and modding all that may aswell replace all the syncros and bearing and any gears that need doing.
 
I am well aware of the issues with 5 speed DCCD's in a WRX type application. One of the guys in our club has a 22B and another an RA. The problems though are around issues with motorsport, not offroading. In those instances the DCCD can be found wanting. Part of this was because the settings would for one section of the course worked well, but you had to change it manually to another setting further along the course and back again. Off road, I think it might be different, but as I am not aware of anyone running a 5 speed DCCD off road I cannot say for sure.

By way of history even the 6 speed DDCD's have changed. In 2006- and I am talking ADM here- Subaru changed to a DCCD which also had something like a plated centre diff in conjunction with the DCCD. What that means is that you can actually run the DCCD without a controller. Earlier 6 speed DCCD (MY05 effectively) did not have this. Getting an after market controller to work on the earlier box in a motorsport application proved difficult.

The point is that I do not think we can look at motorsport issues with the 5 speed DCCD and then say tose issues will carry across to off road applications. Which is why some testing would be nice, if impractical for most. The Cusco centres mentioned- which I was not aware of, also look interesting and something to contemplate.
 
Rally said:
I am well aware of the issues with 5 speed DCCD's in a WRX type application. One of the guys in our club has a 22B and another an RA. The problems though are around issues with motorsport, not offroading. In those instances the DCCD can be found wanting. Part of this was because the settings would for one section of the course worked well, but you had to change it manually to another setting further along the course and back again. Off road, I think it might be different, but as I am not aware of anyone running a 5 speed DCCD off road I cannot say for sure.

By way of history even the 6 speed DDCD's have changed. In 2006- and I am talking ADM here- Subaru changed to a DCCD which also had something like a plated centre diff in conjunction with the DCCD. What that means is that you can actually run the DCCD without a controller. Earlier 6 speed DCCD (MY05 effectively) did not have this. Getting an after market controller to work on the earlier box in a motorsport application proved difficult.

The point is that I do not think we can look at motorsport issues with the 5 speed DCCD and then say tose issues will carry across to off road applications. Which is why some testing would be nice, if impractical for most. The Cusco centres mentioned- which I was not aware of, also look interesting and something to contemplate.
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This makes me think some trial and error is in order before any group buy...
 
Dulagarl said:
This makes me think some trial and error is in order before any group buy...
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Agreed. The best setup is the vortex AWD centre that can be locked with the flick of a switch. I only know of 3 people who have this and use if offroad(Venom, RSR and soon El_Freddo). Too bad it can't be remanufactured for an EJ box and sold otherwise I think all of us would have it. It would certainly remove the 'real 4WD' issue as the only thing between us and them is the locking centre and lockers. I would definately pay good money for it too.

FYI I envy your car so much as it's basically the awesome version of my car! I just couldn't do the H6 as I couldn't live with it overheating.
 
taza said:
Agreed. The best setup is the vortex AWD centre that can be locked with the flick of a switch. I only know of 3 people who have this and use if offroad(Venom, RSR and soon El_Freddo). Too bad it can't be remanufactured for an EJ box and sold otherwise I think all of us would have it. It would certainly remove the 'real 4WD' issue as the only thing between us and them is the locking centre and lockers. I would definately pay good money for it too.

FYI I envy your car so much as it's basically the awesome version of my car! I just couldn't do the H6 as I couldn't live with it overheating.
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That seems to be solved.
 
taza said:
Did the bonnet vents really make that much difference?
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no. I no longer have them.

new radiator, plus other previous mods plus more clearance for headers around bash plate seem to have done the trick
 
Hi Taza,

I had never heard of this mob so I asked around a bit. Two blokes in our club with motorsport experience have already got back to me and suggested that the factory plated diffs were superior, based on the information on the link you provided. If you are interested in more detail let me know

taza said:
Well time for me to spill the beans.

My rear locker I am putting in is Phantom Grip. After much research I found that it works the same as a clutch type LSD but has the ability to lock under heavy accelleration. When one wheel is spinning more than the other (ie diaganl but at the rear lets say) it can sense the friction which causes the springs to bind and effectively locks the spider gears. This would be good for a rocky hill climb, mud (where you nearly always have wheels spin) and sand.
After seeing it in action offroad too I was almost sold on it.

I do have my front geared LSD too which will go in but this won't happen anytime soon. I find diagnal spin to me more of an issue than one wheel spin so effectively like Norrie said a F & R LSD are more beneficial.

Taza
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Rally said:
Hi Taza,

I had never heard of this mob so I asked around a bit. Two blokes in our club with motorsport experience have already got back to me and suggested that the factory plated diffs were superior, based on the information on the link you provided. If you are interested in more detail let me know
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Really?

I have read both positive and negitive reviews on it. Most of which are for motorsport racing and track days. I did find a few who used it in offroad vehicles and were impressed by the results.

More details would be excellent mate!

link?
 
One view was by looking at the mechanical description and pics. With a bit of guess work it wont work as good as a subaru "mechanical" or "plated" diff. Subaru "mechanical" or "plated" diff work with ramps, plates and preload. Preload gives the minimum torque transfer amount (ie low throttle car park or coasting around a corner) The ramps utilise the input torque and torque difference (left to right) to force the plates together harder and equalise speeds on both outputs. Both of these mean both rear wheels will provide torque circumstances. But the ones pictured look like an economical step up from a Viscous LSD but not sure where it would sit on the scale from open to plated.

It is not a replacement for a real LSD and has unpredictable results. The basis for it was found in the very simple Group N trick of shimming a diff tighter, which does wear out spider gears more rapidly but it works a treat and unlike the phantomgrip is quite predictable in what you get for any number of shims you insert.

Diff shimming has very much disappeared now, given LSD's are not hard to get and most homologations have added them. But it's a good Historic trick to remember.

As I said before, I feel there is a difference between motorsport and offroading and this needs to be kept in mind.

I cannot provide any links as the site is access to members only
 
Dulagarl said:
https://www.perth-wrx.com/vb/genera...460-best-performing-non-dccd-centre-diff.html

a few reasons why DCCD can be a problem. I have a H6, and am not confident that I wouldn't wreck it.
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I know most of these guys and they drive VERY hard and most are punching out between 300 & 500hp at the wheels so totally different to our application of trying to crawl over a rock or up a steep track, Doug is a rally driver and Tuna has been known to put more than 30psi through a stock motor.

Forget doing a group buy on anything, you'll end up paying import duty & 10% GST, also most Japanese dealers don't give enough discount to make it worth it, I know JapanParts won't do group buys and they supply heaps here in WA......It'll cots lots more and take longer going through customs, also no door to door delivery.
 
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d_generate said:
Forget doing a group buy on anything, you'll end up paying import duty & 10% GST, also most Japanese dealers don't give enough discount to make it worth it, I know JapanParts won't do group buys and they supply heaps here in WA......It'll cots lots more and take longer going through customs, also no door to door delivery.
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Unless we do a group buy on an Aussie product, or at least a product sold by an Aussie company...no import duty...
 
Ahhh, they pay import duty and I can assure you they will pass it on, how many 12kg diffs you seen
A. produced in Australia.
B. at a reasonable price.
 
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