I have owned a 2002 WRX wagon, a 2005 STi and currently a 2007 STi. My question relates to what happens with the center differential when the emergency brake is applied. The genesis of this question is as follows:
My 2005 Sti would rotate quite nicely when I applied the e-brake. The rear wheels would lock, and the fronts would keep rotating, allowing for a controlled and predictable rotation. It certainly felt and acted like the center diff opened to allow this. I practiced this many times at Team O's winter safe driving school (the STi's tend to push with wide snow tires sometimes, so a quick pull on the chicken stick and the car would begin to rotate and momentum would carry you around nicely).
The 2007 is a totally different experience. The first few times I tried this in snow, it felt like all four wheels locked and it just kind of slid along, much like a non DCCD diff (like my 2002 wagon). Some rotation, but nothing like the 2005. Well, last evening I confirmed what I was feeling, when the e-brake is pulled, the front wheels also come close to lockup, seems not quite as much as the rears, but still very positive connection between front and rear and not nearly as open as with the 2005. In both scenarios, the diff is in auto. What gives?
Are the electronics and center diffs that different between 05 and 07? Do I have a problem with my center diff on the 2007? My next test is to try this with the diff in the fully open position to see if it makes a difference. It is not that big of a deal as I use this technique only in the snow or other loose surfaces to assist in rotation in places where throttle steering is not an option and push is a concern, but nevertheless this is hampering a tool in my driver's tool kit.
My 2005 Sti would rotate quite nicely when I applied the e-brake. The rear wheels would lock, and the fronts would keep rotating, allowing for a controlled and predictable rotation. It certainly felt and acted like the center diff opened to allow this. I practiced this many times at Team O's winter safe driving school (the STi's tend to push with wide snow tires sometimes, so a quick pull on the chicken stick and the car would begin to rotate and momentum would carry you around nicely).
The 2007 is a totally different experience. The first few times I tried this in snow, it felt like all four wheels locked and it just kind of slid along, much like a non DCCD diff (like my 2002 wagon). Some rotation, but nothing like the 2005. Well, last evening I confirmed what I was feeling, when the e-brake is pulled, the front wheels also come close to lockup, seems not quite as much as the rears, but still very positive connection between front and rear and not nearly as open as with the 2005. In both scenarios, the diff is in auto. What gives?
Are the electronics and center diffs that different between 05 and 07? Do I have a problem with my center diff on the 2007? My next test is to try this with the diff in the fully open position to see if it makes a difference. It is not that big of a deal as I use this technique only in the snow or other loose surfaces to assist in rotation in places where throttle steering is not an option and push is a concern, but nevertheless this is hampering a tool in my driver's tool kit.
