by Dan Chambers on Mon Aug 14, 2006 8:48 am
My thoughts:
As someone who designed tracks for 2+ years in SDR, I can say that although "challanging" to new drivers and a "good teaching tool" for Instructors to teach new A-X drivers car control, you can accomplish the same learning/teaching parameters using two 90-degree turns linked with a very short straight. Car control, throttle steering, and balance of the car can be accomplished with both designs, however a loop represents an unrealistic condition in real-life auto competitions (unless you like to compete against cars on round-abouts in Europe and Australia - where they're prevelent) where as linked 90's occur in many courses as well as on the highways and twisty mtn. roads, and are really quite challanging.
Also, there is no way to teach "linking turns" in a loop, whereas there is ample opportunity to teach linking-turns with two-90's split with a small straight. Even a double-apex sweeper afords more teaching technique than a loop. Incorporate two linked 90's and a double apex turn bonded with a straight, and you have infinitely more teaching tools than a loop.
From an event mamagement point of view, a loop creates havoc! Corner-workers are at risk (if you stand on the inside, you have to avoid accidental over-steers, and if you stand on the outside you have to avoid accidental understeer), the pause between starts is a bit greater (as Tom Tweed points out) and the more experienced drivers - who are often Instructors - may not show up since driving a loop is not that interesting to them .... thus you get a poor Instructor to Student ratio and the Instructors that do show up gripe and complain about working too hard all day.... justafiably so.
SCCA runs a very different type of event. Often - as I understand - the drivers only get 3 laps all day, and the total number of laps for the day is under SDR's typical daily total of 1200 to 1500 TLPD (total laps per day). Loops represent more hinderance than advantage, based on my experience, and SDR's experiments of the past.
Just one perspective from a former A-X Chair and current Co-CDI.
Dan Chambers"It's
just a "well prepared" street car ... or a very, very well-mannered track car."

1983 SC #91 3.6L, "Black Pearl" Livery
1987 944 (gone but not forgotten)