Does the E-brake disengage the center diff in a 4EAT?

[GTS Jeff]

I have an 05 2.5i 4EAT. Driving around, it understeers like a pig. In wider corners, I can set up some oversteer with weight transfer, but I find that the only way to make the car tuck into a tighter corner is with a quick jab at the e-brake.

 

Now I know traditionally locking the rears on an LSD center diff is not a good idea, but since the 4EAT's center diff is computer controlled clutches, I'm wondering if it knows to disengage with e-brake use. I know the STI does this and there's no reason why the 4EAT couldn't...but I want to be sure.

[rao]

No.

[GTS Jeff]

That was enlightening. Do you have anything to support that? Because it really doesn't make sense for it to not have that feature. It's a computer controlled electromagnetic clutch system and the computer is already varying the lock constantly...

[rao]

I didn't realize that this was an essay question

 

 

The TCU doesn't have an input for the parking brake so it has no idea that you are imitating Bo and/or Luke Duke at any given time It does know when you depress the brake pedal though.

 

 

Have fun

[GTS Jeff]

Hmmm...what does the diff when the car is coasting then? Cuz the only time I'd use the ebrake is when I'm off the gas. If it's unlocked when off throttle, it might be ok...

[frank_ster]

ok i was reading through what the computer does for the 5 eat ..

 

in 5th gear the diff is open

 

the pressure is varing depending on throttle position

also steering angle input

and also slip input

 

my car 4 wheels jacked up ..

in drive wheels spin to 20 mph .. i yank the hand break and all 4 wheels stoped together.

 

but i can hand break corners .. and i'm sure if your hand break is adjusted properly i think you can too ..

[mwiener2]

4eat is 90% front wheel drive... which is why you can't kick the backend out without a little handbrake action