Jump to content
Ultimate Subaru Message Board
kobushi

WRX Differentials

Recommended Posts

I am trying to find out which direction the driveshafts to the ront and rear diffs. turn during forward motion in a WRX.

 

Trying to find out if my application will mate with the proper spin.

 

Is the front diff a seperate unit like the rear, or is it integrated with the trans/center diff somehow? Could the front diff be removed ad used stand-alone like the rear? Or would I just need to use 2 rear diffs?

 

My plan is to mount a motorcycle engine to each differential to power all 4 wheels. The motorcycle engine spins counter clockwise as you face the output shaft so if the diffs are normally turned clockwise viewed from the driveshaft, then it'll work fr sure...

 

I could turn the diff upside dwn, but I don't know if that would effect the LSD functionality.

 

Any thoughts or info would be appreciated.

 

Thanks,

--Ash

Share this post


Link to post
Share on other sites

I don't know the rotation direction off the top of my head.

 

The front differential is integrated into the transmission casing. I'm not sure mounting it upside down will work, due to the shape of the case. You probably would not get adequate lubrication.

 

Here's some pics of the rear diff off my turbo legacy (which is similar to the WRX)

 

The LSD is a sealed viscous type and should be able to operate in any direction.

 

Other thing to note. The WRX has a final drive ratio of 3.90. However the center diff's ratio is 3.545 because there is a 1.1:1 gear ratio from the rear transfer gear.

Share this post


Link to post
Share on other sites

The rear diff flange rotates clockwise viewed from the front of the car going forward.

 

Youre in luck. OR you could mount a sprocket on the flange and use a chain drive, then locate youre motor wherever suits, and facing whichever way suits.

Share this post


Link to post
Share on other sites

I know that the STi as of 2005 uses a helical diff in the front... What about the rear?

 

Is it clutch, VLSD, or helical?

 

It makes sense that a VLSD could be turned upside down if need be (any diff I find to use will have to either be turned upside down or the gears reversed in either the front or the rear since spin will be in opposite directions); but what about helical diffs Are they up/down sensetive?

 

I'll be putting a lot of power down in a light car, so I'd prfer helical IF I can make it work... if not then I can fall back on VLSD since at least it will function :)

 

Tanks guys,

--Ash

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×