04/17/2011 The dp4 is a track car and is not really designed for autocross (too little suspension travel/ground clearance, shocks/springs set up for downforce, etc). Still, people kept asking us how it would do and to be honest we were curious ourselves... So we decided to try one - an Oregon PCA event in the PIR parking lot. The lot is VERY bumpy so we knew it was going to be a torture test for the car with its 3/4" ground clearance and 800 lb/in wheel rates. For the driver, too - Karl would be driving and we would just play support crew so he'd be the one to take the bumps. After about 2 seconds deliberation Karl decided to wear the HANS device. Good choice!
The day started out sunny but cold, about 40F warming up to low 50's eventually. Rain the day before left numerous puddles but the course was reasonably dry overall. The bumps were initmidating and I was cringing just looking at them, imagining the sound of the floor being torn to shreds.
The first couple runs showed that while the pavement was indeed a challenge the car handled it resonably well, albeit bouncing around to the point of seeing air under the tires. But the biggest issue was that we could not get any heat into the tires. On the track it typically takes a lap or two to heat them up and the car is very loose until that happens. With 5+ minutes of waiting between 40-second runs we were left to dealing with lots of sliding. On top of that, the bumps precluded the use of full throttle and the clutch required a slow rolling start. Not what you'd call optimum.
(Photos courtesy David Paris).
By the 4th run Karl pretty much figured out what needed to be done (smooth steering, feathering throttle, no full throttle, easy on the brakes) and set Fastest Time of the Day at 40.505 - see official results for competition's times. The video shows Karl at work - here.
Overall, a fun and educational day - many thanks to Oregon PCA for hosting us and putting on a smoothly run event. That said, we probably won't be doing much autocrossing with this car since this isn't what it was designed for. Some of the upcoming models (dp2, dp6) will be better suited to the A/X environment although neither is being targeted at A/X as such.
Some more pictures below, just because.
This is the last entry in this particular blog since the design and development of the car is pretty much done. I will start a new blog for its life as a 'regular' car in the stable the next time we use it as such.