Thursday, April 24, 2008

RSW Time Attack @ SWMS 4.19.08

Last weekend I attended the second monthly Racing Southwest "DriftRoad Cross" at Sandia Motorsport Park. This is the event's first season, and it had a decent turn out. It was set up as a time trial, and the course consisted of a combination of a section of the road course and a very small and tight autocross section. The drifting took place on the inner oval of the track at the time time.
This was my first time on a road course so with this in mind I was not disappointed that the track setup was rather short and limited the top speed. Although the autocross course was so tight that it necessitated going all the way down to first gear, this proved to be somewhat of an equalizer between the bigger and higher powered cars that could have an advantage on the faster parts of the road course and the smaller more maneuverable lower powered cars that were well suited for the tight autocross section. Lucky for me, although my car is no a Mini or a Miata by any means, it still has a decent balance of power, traction for it's weight and size, and maneuverability. Evos are well known for excelling at both autocross and road racing, so I definitely wouldn't be able to use the car as an excuse. I was going to look bad in a good car that my driving skill or lack thereof could not even come close to taking full advantage of, and I was prepared for that.
Regarding other concerns of the car itself, I knew that my old Falken Azenis RT615 tires which had been in sub-freezing temps in my shed for the last two years were sufficient for spirited street driving and cautious road racing, they were less than ideal for pushing the limits of my and the car's abilities. This was a perfectly appropriate handicap though, as it caused me to drive all the more conservatively and pay more attention to getting acquainted with driving, the track, and my car. After all, I had no intention of actually racing today. This was to be an opportunity to test my patience, get the feeling of driving on an actual racetrack, become more familiar with my car and it's new suspension, and try to squeeze in a little bit more of all of the above before the next SCCA autocross event. In addition, having relatively limited grip of street tires also turned out to be very telling of my mistakes and showed me where I was upsetting the car too much by causing loss of traction.
Until this point, I had only driven the coilovers very gently on the street on all-season tires and about 5 autocross runs on the Azenis, and had not really tried all of the different settings. I started out with the same setup that had been recommended for good rotation in autocross (full soft in front, close to full-hard in back), which was more by accident of forgetting to back off the damping before my first lap. this proved to be WAY too loose, as the back end stepped out a few times in very "exciting" fashion at even light lifting of the throttle or braking during a turn. This also amplified the fact that my movements were too sudden and suffering from a reactive rather than anticipatory approach, and forced me to smoothen my inputs and do everything sooner than later.
The second lap I backed off the damping in the rear significantly, and this already helped reduce the excess oversteer immensely and get the car more neutral. I know that Evos are more known for understeering than oversteering, but I should mention that the coilovers have unusually high spring rates (as much as 875lb/15.5k I later found out!), and a hefty 26mm rear sway bar to boot (stock is 22mm!). Even after this adjustment the car was still prone to losing rear traction relatively easily. I don't know if it was due to becoming more familiar with the track, the damping adjustment, the tires beng warmed up, or all of the above (and it really doesn't matter) but I took a good amount of time off. I can't remember exactly how much, and the times have not been shared yet, so I all I can say is that it was significant. But times are almost irrelevant to the difference of how I and the car felt compared to the second run.
The most informative part of that run though, had nothing to do with the car at all. It was having Brenden Tolsch ride along. Brenden has been doing very well in his first season of autocrossing his S2000 at SCCA events and has some prior experience with HPDE's like this. Immediately following the run he had some very helpful feedback for me. I had been riding the inside of the turns too soon and too long, and not using the full width of the track enough. I needed to be going FAR wider at corner entry and allowing myself to go far wider at corner exit as well. His advice proved to be spot on, as I cut more than a second off of my previous lap.
Each lap (for total of about 8 or 9 if i remember correctly) I was able to shave off decent amounts of time and go from the pathetic and disgraceful time I started with to a less embarassing but still humbling lap time. I really wish I had times to reference and compare, but they were never posted and I have since forgotten exactly what they were, and don't want to post inaccurate speculation. What I do know is that my times went down consistently, and the difference in time cut off each consecutive lap grew even greater toward the end. Usually it's the other way around for me. It may be a good thing I don't have the times anyway, because they were indeed nothing to be proud nor ashamed of, but also were not the point of the whole event.
By the end of the night, I felt that I was just starting to get the hang of it after my last run, which is how it always goes. I came to the conclusion that in combination with my high spring rates, I simply have too much rear bar. Even under steady state cornering (where a rear stabilizer bar's effect is most noticeable) and constant and moderate throttle and steering through the turn, the rear end was losing traction too easily. While this could be desirable in autocross, it was not how I wanted the car at high speeds and on a faster, bugger, more open racetrack. Combined with the fact that even at the last autocross I felt that the car was too skittish and oversteered too much, led me to believe that changing the bar to a softer setting or replacing it with the stock one would be desirable. However, that is a change I wanted to feel without too many other variables at the same time, and I already had some other more important variables in the works for the near future ;)