Im upgrading differentials on STi 3 wagon.
I bought front ATB quaife. - I think good improvement. Understeering under power is 50% eliminated.

1) Now the question is what I can expected with front ATB and rear LSD diff.
2) Or if front LSD and rear LSD would be better.

3) Front and rear differentials are often in offers but what about uprated central diff? I havent hear about car with uprated central diff. Which manufacturer? Which improvement I can expect?

And last: on scoobynet i red that type R has 35/65 distribution. I look on the picture of gearbox and both types standard and type R looks simillar (only difference is central differential (only different locking device.......) Where is differention in gearing? Where are the parts that makes 35/65 against 05/50 distribution?

 

I had a Kaaz plate front diff in my car. It handled better than the standard setup, but the noise it made and the feel through the wheel at very low turning speed used to annoy the hell out of me. Eventually put a standard one in.

Worth mentioning though, my plate diff was at full lock, you can build the plates in certain ways (as you probably know) to make the diff have less lock, 50% would prob sort the low speed stuff out, but I didn't want to risk it, so went for standard.

Probably no help, but thought I'd let you know

 

You mean that you cen have diffrent "pre-tension" in LSD. Yes I know.
ATB function is only in load mode. Under braking this diff have no function.

Also looking for answer if the car will be after ATB/LSD or LSD/LSD more oversteered or not.

Seeking best differential combination. :-)

 

Subaru's Suretrack is of course better than the ATB Quaife diff as it works all the time but the difference in price is remarkable, double!
On the other hand ATB can't "drive" as good as Suretrack without throttle or in very tight corners with different surface levels as it needs more "base" traction to the internal wheel in order to give some torque to the outside, it feels as you loose instantly all the power when the internal wheel is in the air!
On all other situations it's same if not better (I could describe it more fluidy/"continuous") from the Suretrack and may be more progressive. All from personal experience and I am not expert, just my feeling from a WRX02 w/Quaife ATB and STI03 w/Suretrack.
JIM

 

And your car is now more oversteered undr throttle?

 

Isn't my car but a friend's cars and yes it oversteers more than before (MY02) but it turns also better IF you like throttle oversteer.
You can handle it as you like from mild understeer to bad oversteer but it's always predictable-adjustable via throttle and this is more important for me.
For my car (WRX03) a Whiteline adjustable rear anti roll bar (24mm) with some personal alignment settings (1 degree camber front-zero toe and 1,1 degrees camber rear-15min/wheel toe out) completely transformed it believe me!
It really depends from how you like your car!
JIM

 

Next days i will install rear cusco swaybar (supplied with hardened mounts).
My previous car was BMW M3. I need more oversteer than my Sti 3 offers.

 

Rear ATB or Suretrack diff + adjustable rear anti roll bar + 10-15min per wheel rear toe out with max camber front is my favorite modifications and gives you quite a lot of oversteer without problems in the wet, no loss of comfort and most important predictability/adjustability!
Obviously I like too oversteer mate and I didn't own a M3 only Imprezas, Peugeot Rallye and Almera GTI...
JIM