Perth-WRX.com  

Go Back   Perth-WRX.com > General WRXing > General Subaru Discussion
Register Diddy Kart ArticlesAll AlbumsBlogs FAQ Members List Calendar Search Today's Posts Mark Forums Read

Westcar Detailing
Welcome to Perth-WRX, click here to register!

View Poll Results: Which non-DCCD centre diff is the best?
4Kg (Standard) 3 7.89%
12Kg (Sti) 27 71.05%
20Kg (STi-RA?) 8 21.05%
Multiple Choice Poll. Voters: 38. You may not vote on this poll

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 06-04-2010, 08:20 PM
subarooboy's Avatar
Sir AntiLag
Member
 
Join Date: Jan 2006
Location: Canning Vale
Posts: 461
Thanks: 0
Thanked 0 Times in 0 Posts
subarooboy at standard level
Default The best performing non-DCCD centre diff??

Ok, got into a bit of a debate with some friends on the weekend re: centre diffs. Of course there is Subaru's flagship DCCD which I have flogged in every shape and form of STi round the track while instructing (perks of the job!) and have now wired up in my 6 speed, tested round the track and fairly impressed!!

However to my knowledge Subaru have also released 3 other non-DCCD centre diffs with factory set pre-loads. These are 4Kg, 12Kg and 20Kg? Respectively...

The 4Kg centre diff being most common in most WRX in my experience is fairly doughy inducing heaps of understeer (which most attempt to somewhat 'cure' with suspension mods etc), the 12Kg seems to be superb offering a well balanced, more nuetral drive, but have never tried the 20Kg- which I hear can get a little tricky and end up throwing the car back into understeer issues again.

So thought I'd throw out this question to the guys who have tinkered with any/ all 3 of these variations or had them inclusive within vehicles (eg- early STi's) to get their opinions... what are the differences? And which did you feel was the best??
__________________
"...even my Grandma can drive fast in a straight line"
Reply With Quote
  #2  
Old 06-04-2010, 09:22 PM
jEstEr?'s Avatar
Sign me up!
Insufficient registration
 
Join Date: Jul 2005
Location: Perth-ish
Posts: 8,363
Thanks: 26
Thanked 64 Times in 47 Posts
jEstEr? knows their stuff
Default

there is also an 8kg
__________________
MY93 Impreza GX 1.8L, 0hp, 0nm
Reply With Quote
  #3  
Old 06-04-2010, 09:37 PM
Mister Two's Avatar
Sleeper Wagon
Member
 
Join Date: Mar 2006
Location: Surface of the Sun
Posts: 4,043
Thanks: 5
Thanked 8 Times in 8 Posts
Mister Two at standard level
Default

There are also the Cusco Tarmac Center diffs which is very similar to running a DCCD box with no power going into it.

And Cusco and ATS also make 2 way plated mechanical center diffs. Similar in operation to a 2 way rear LSD. It locks up hard under power and throttle off. And opens up when coasting.

I haven't driven on either of these though.
__________________
RS Liberty - Because WRX's are only good for parts...
Reply With Quote
  #4  
Old 06-04-2010, 10:07 PM
dtrally's Avatar
Sign me up!
Handbrake!!
 
Join Date: Jan 2007
Location: Perth
Posts: 2,484
Thanks: 6
Thanked 113 Times in 78 Posts
dtrally is a gurudtrally is a guru
Default

Just to clarify Joel, To my knowledge the 12 and 20Kg/m were not STi and STi/Ra default fitment. To assume that any STi or Ra automatically has one would be incorrect.
I've never found anything other than a boring old 4kg/m softie in any road going non dccd STi. If the car was rallied or 'dirt trial' raced in Japan you may be lucky enough to find one fitted.

I've tried all of them.
Stock 4 kg needs help to stop excessive front wheel spin.
12 is my pick as better than the rest. Does the job nicely, no nasty side efects.
20 behaves like a 12 but has noticable bind on tight turns.

My old series 1 Legacy had approx 220 horsepower at the most. A 20kg/m may have been more beneficial if the car was more powerful. I now have a DCCD centre in there and I'm seriously considering going back to a 12. The DCCD is less predictable.
I did loads of *handbrake turns with the 12 and the 20, so don't let anyone tell you it can't be done. *must have a hydraulic handbrake, plate rear diff also desireable.
Reply With Quote
  #5  
Old 06-04-2010, 10:42 PM
Denver's Avatar
Sir AntiLag
Member
 
Join Date: Jul 2005
Location: Perth
Posts: 490
Thanks: 0
Thanked 0 Times in 0 Posts
Denver at standard level
Default

cusco tarmac gear is the diff of choice for a tarmac based car, 65/35 rear front power split, has turned our car into an oversteering demon, but with a working front diff, entirely driveable, will not fall apart like a electronic dccd centre at around the 300hp mark and is about the $1200 mark making it excellent bang for buck
__________________
Jesus Built my car, Its a love affair, Mainly Jesus and my hotrod
Reply With Quote
  #6  
Old 07-04-2010, 02:26 PM
Darren's Avatar
YOINK!!!
Member
 
Join Date: Jul 2005
Location: Dizzy!!
Posts: 357
Thanks: 0
Thanked 0 Times in 0 Posts
Darren at standard level
Send a message via MSN to Darren
Default

I was very happy with my 12kg center and it did reduce understeer whilst allowsing predictable tail out action. I have never heard the stories of not being able to use the handbrake with the 12kg but I can also confirm handbrake turns can be achieved with a 12kg center.
__________________
When in doubt, Pull it out...
Reply With Quote
  #7  
Old 07-04-2010, 02:40 PM
tuna's Avatar
Sign me up!
Why stop at two bar?
 
Join Date: Jul 2005
Location: Where horsepower is cool again.
Posts: 5,558
Blog Entries: 5
Thanks: 6
Thanked 93 Times in 47 Posts
tuna is a gurutuna is a guru
Default

i like burnouts in general, so any diff that encourages it, can only be a good thing.
__________________

Long live the WRC
Reply With Quote
  #8  
Old 07-04-2010, 06:37 PM
Hurtenstein's Avatar
Subaru Tech Division
Member
 
Join Date: Mar 2006
Location: C to tha V
Posts: 1,597
Thanks: 0
Thanked 4 Times in 4 Posts
Hurtenstein at standard level
Default

Quote:
Originally Posted by Denver View Post
will not fall apart like a electronic dccd centre at around the 300hp mark
Is that true? A regular occurrence like gearboxes?
__________________
Balls.
Reply With Quote
  #9  
Old 07-04-2010, 10:02 PM
Denver's Avatar
Sir AntiLag
Member
 
Join Date: Jul 2005
Location: Perth
Posts: 490
Thanks: 0
Thanked 0 Times in 0 Posts
Denver at standard level
Default

protofail kept toasting his, he did some digging and found a lot of people making over 300 ATW had simular issues, switch to tarmac gear, problems go away..

being electrically controlled, increasing the power input by a very large amount will in time kill it, especially if your motorsporting a lot, mechanical solutions are generally the only reliable way to do these things as power increases will not affect them as much...
__________________
Jesus Built my car, Its a love affair, Mainly Jesus and my hotrod
Reply With Quote
  #10  
Old 07-04-2010, 10:37 PM
jEstEr?'s Avatar
Sign me up!
Insufficient registration
 
Join Date: Jul 2005
Location: Perth-ish
Posts: 8,363
Thanks: 26
Thanked 64 Times in 47 Posts
jEstEr? knows their stuff
Default

I am of agreeance, in any form of motorsport or ahrd use the DCCD centre is really only good on a stockish powered car
__________________
MY93 Impreza GX 1.8L, 0hp, 0nm
Reply With Quote
Reply

Tags
centre, diff, nondccd, performing

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


LinkBacks (?)
LinkBack to this Thread: http://www.perth-wrx.com/vb/general-subaru-discussion/33460-best-performing-non-dccd-centre-diff.html
Posted By For Type Date
Rear limited slip diff This thread Refback 24-04-2014 11:29 PM
Rear limited slip diff - DirtyImpreza Forums This thread Refback 18-12-2012 02:41 PM
AWD 12kg Centre Diff LSD - Page 4 - OFFROADSUBARUS.com This thread Refback 23-05-2012 05:06 PM
AWD 12kg Centre Diff LSD - Page 3 - OFFROADSUBARUS.com This thread Refback 22-05-2012 06:52 PM

Similar Threads
Thread Thread Starter Forum Replies Last Post
FOR SALE: 5 Speed gearbox/ rear diff + 12kg Centre diff subarooboy For Sale 11 13-12-2009 01:43 PM
DCCD diff WRXation Mechanicals 14 23-08-2009 08:42 PM
F/S DCCD Centre Librs1 For Sale 2 24-03-2008 09:52 PM
DCCD centre,controller and rear 180 clutch pack diff spikey For Sale 0 26-03-2007 04:11 PM
Ver 5 type R DCCD centre diff spikey For Sale 0 06-07-2006 07:32 AM



Welcome to Perth-WRX, click here to register!

All times are GMT +8. The time now is 08:12 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO