waffoo

I was wondering how the power is split from the engine to the front/rear wheels in a WRX? Is it 50/50?

Sorry if this has been asked a hundred times before.

ratboy

iTrader: (4)

I thought it was but got told 60/40 the other day....so will watch this thread with interest...........

waffoo

60 to the front?

johngoulding

iTrader: (7)

60/40 it is actualy 59/41 i think but its 60/40 by anyones terms for definate as when i got the cusco lsd fitted i was told that it would still keep the 60/40 split and plus i know its 60/40

waffoo

60 front then? I would rather 60 to the back!

johngoulding

iTrader: (7)

im sure its 60 to the back to be honest as if u give it some beans round the corner on a non dccd car then the back gives way with a little spin this could be due to the cusco lsd i have but i would say it feels more to the back , but thats only an opinion im sure someone else can confirm if the 60 is front or back

Splitpin

Sheesh, would love to know who's going round saying that?! The power split on the viscous centre diff is 50/50. It's a conventional bevel gear diff, plus the viscous coupling.

johngoulding

iTrader: (7)

here we have copied and pasted from an auto testing magazine

Fundamental to the Impreza Turbo's 'cult car' reputation for dynamic handling and grip in all weather conditions is its all-wheel-drive (AWD) system. This features a centre differential with viscous coupling. In normal and dry road conditions torque is distributed 60/40 between the front and rear wheels. But in wet, muddy or icy conditions, the viscous coupling senses which axle has the most grip and distributes torque accordingly. The P1 also shares the Impreza Turbo's limited-slip rear differential. This further distributes torque - this time to whichever rear wheel offers the most grip.

johngoulding

iTrader: (7)

so u were half right mate lol

johngoulding

iTrader: (7)

sorry "website of the magazine "

johngoulding

iTrader: (7)

so i was wrong aswell its 40 to the rear

waffoo

Wish I had held out for an STI. That'll be why my front tyres wear out faster than the rears. Thanks for the answers/posts. 60% front. Wonder why I get understeer?

Splitpin

A significant percentage of what you come out with seems to be bollocks John so I'm not sure why you bother. Anyway, that magazine article is bullsh*t. The idea that the car has a FWD bias is laughable, as is the idea that a viscous coupling can "sense which axle has the most grip and distribute torque accordingly". As, indeed is that the transmission changes its behaviour between "normal and dry road conditions" or "wet, muddy or icy conditions".

As above the centre diff on non-DCCD Imprezas is a conventional planet and bevel gear unit. It cannot split its torque anything other than 50/50. Find a knackered one and take it apart - it's easy enough to see how they work that way.

The viscous coupling is a very simple passive device designed to ensure some level of torque transfer from an unloaded axle. It isn't active, and doesn't alter the diff's fundamental torque distribution. End of.

Splitpin

Your front tyres wear quicker because they have more weight on them than the rears, and because you steer with them as well as put drive through them.

With respect, ignore John.

Because your car is set up to do so.

waffoo

Right on. I was gonna ask about viscous couplings but looks like I don't need to, but will ask how much differance DCCD can make?

ratboy

iTrader: (4)

I had this decusion for ages on another forum and was sure it was 50/50 but everyone said it was 60/40.
Nice to be right about something for once.....

Splitpin

Oh - incidentally John, what website? And Waffoo - there's loads written on conventional vs DCCD stuff - Search is your friend, or a quick scroll down the transmission forum.

waffoo

How much differance can DCCD can make then?

Splitpin

They'd probably read this article JG is referring to. The irony is that I wouldn't be at all surprised to find the author got his info from some post or other on snet. And so it goes round all over again.

ratboy

iTrader: (4)

Seems strange that most folks know the in's and out's of these cars but most dont know this very fundamental and rather important thing.
I wasnt at all sure but nice to have it confirmed at last.
Trouble is,now ive got dccd so its again.
Isnt it something like 63% or 67% rear with this when turned off?

waffoo

Found this. Subaru glossary- terms and definitions. Below is a snipit.

Continuous AWD: Subaru manual transmissions use Continuous AWD, normally 50/50 front-to-back power split and use a mechanical viscous center differential to to vary the power split when there is a loss of traction.

The rookie

iTrader: (1)

DCCD is 40/60 torque split ALL THE TIME, all DCCD does is adjust the limited slip function.

As has been said WRX is 50/50, why is it people who don't know love to answer so confidently........

Simon

johngoulding

iTrader: (7)

so whos right and wrong ? so many varried opinions and facts ,me personally i was told by far east performance it was 60 40 ?

johngoulding

iTrader: (7)

ps " bit harsh splitpin , cheers m8

joz8968

iTrader: (13)

Non DCCD set up - i.e. open front diff; VC centre; VC rear - is 50/50 in steady state driving with no slip on any wheels.

All of Splitpin's points are correct (as is so often the case...).

This is prob the reason why Subaru like to emphasise and market it as "AWD" (ALL-wheel drive), rather than 4WD. Gives more emphasis on the fact all wheels are contributing equally to the grip for more of the time, unlike some other 'token' 45:55, 40:60, 35:65, or even 30:70, systems...

ratboy

iTrader: (4)

36/64 isnt it?