Friday, October 20, 2006

ECU trends at SAE Convergence

He (Steve Magner of Ford Motor Co) used the term "high degree of freedom" (HDOF) to describe the typical modern powerplant, and explained that the table-based method ("full factorial mapping") of calibrating ECUs has basically reached its limit. Where as it's desirable to complete the calibration of a new engine in about four months, a HDOF engine currently requires up to 15 months to fully define in the laboratory. In one example, developing just the timing maps for the EPA' s fuel economy test cycle involved 630 states of operation and three months of time on the dyno.

Via Autoblog

Tuesday, October 17, 2006

2006 2.5L WRX STI test drive

Managed to test drive the 2.5L WRX STI. Motor Image supplied a basic model in black, with more than 2000 km on the odometer... tires are RE070 with 225 width, slightly worn, but still road-worthy.

First things first, the good stuff. Good usable torque down low in the rev range, decent interior. Suspension is firm, maybe a little too firm for local roads. That's about it.

Now on to the stuff I didn't like.

Didn't get the chance to pop open the hood, but I suspect this model has a drive-by-wire throttle. The idling is uneven. The RPM nose-dives, sometimes even hitting the big "0" on the tachometer when making a turn, and the steering suddenly goes heavy at times. A quick prod of the throttle yields... NOTHING! Ironically a DBW throttle integrated with a good idle control system should have eliminated these problems, yet here they are rearing their ugly heads! And this is in a stock car! I've driven some very temperamental cars with aggressive cam overlaps and they don't exhibit symptoms as severe as this.

Secondly, the gear shift. Pushing the gear lever into first feels rough, as if the synchronizers are worn. Second is just as bad. Third and up feels fine though. Now if you're just moving off slowly from standstill, it's not so bad. But when the throttle is floored, and you depress the clutch pedal to shift into 2nd, you find that the linkage shifts so badly you find yourself shifting into 4th instead of 2nd!

Third... the differential is screwed. Making turns is difficult, and you can feel the inside and outside wheels disagreeing on the proper speeds to maintain. It became so bad until a loud "KLONK" could be heard emanating from the back. Eventually I just gave up and set the DCCD torque split to a RWD-biased configuration.

Maybe I was unlucky and drove a lemon. Maybe they need a reason for customers to buy the S204. I drove Edmund's 2.5L WRX and that was by far a much better drive. Sure the power is not up to par but it's a much better value for money. I would be amazed if anyone still put a deposit on it without at least giving an Evo 9 GT a test drive first.


So my sister-in-law, who's a teacher, was trying to instill in my nephew a sense of industriousness.

"Mommy works hard at school so that she gets paid and can buy things for the family."

At which point the little boy looks stunned.

"You mean you get paid?! I hate going to school but I still do, and they don't pay me!"

Couch potato