06 Nov 07
Time to investigate the DCCD (Driver's Control Centre differential). This electronically controlled limited-slip differential alters the torque split between front and rear axles through a range from 50/50 to a rear-biased 41/59. The previous STi had a similar system, but what is new is the presence of three automatic modes instead of one. Also new is a button to tab, in manual mode, the required amount of rear bias, formerly achieved with a thumbwheel.
I've been running in regular Auto, which is probably why the STi feels inert. It's strange, because Auto felt fine in the old car. If I switch to Auto Plus, the centre diff will tighten, which is good for slippery-road traction but bad for driving fun. So I select Auto Minus, which loosens the diff and allows a readier transfer of torque to the rear when the front wheels' grip is fading. We'll switch the VDC (Subaru's take on ESP) out of Normal and into Traction, too. That should allow a bit more freedom to drift.
That's better. Immediately the steering sharpens, because the liberated rear end is helping the front to turn in. I can power out of a corner without the front washing wide and the engine fading, and on that scary right-hander I no longer feel I'm going to scoot off the outside of the bend. The nose is biting better and it's easier to take the right line through the corners, but still that STi tail-flourish of old is eluding me as I leave the tighter bends.
Drastic action required. VDC off, DCCD manual and tabbed to maximum rearward torque bias. Two more laps; will the STi's character escape at last from its electronic straitjacket?
