Oct 2, 2006 update to the Mazda STS2 Miata project car


Wow, what a week! Its been a career goal to win the Pro Solo Overall championship and that’s just what we did last week. Along the way, another class win in STS2 (seven in a row!), the year-end class championship and the Street Challenge championship were earned. It was a long week and here’s the story.

Going into the event, we were leading class points and in contention for Street and Overall. To get prepared for the new surface at Heartland Park Topeka, we came to town early to participate in the Test and Tune that the west coast folks were holding. That gave us two extra days to tweak and tune. We’ve been running a lot of front toe-out (1/2 inch total), based on our early-season testing, but have not had time to re-check this once the rest of the suspension was dialed in through the season. So we compared this setting to a more traditional 1/4 inch setting and found this to be an improvement. We lost none of our initial turn-in but removed a bit of mid-corner push in sweepers.

Next, we played with rear sway bars to get a basic balance. Normally, we run the stock bar (12mm) for big courses on medium-grip asphalt. With the expectation for tighter courses and smaller radius turns, we decided to try more rear bar. With four bars to choose from, we went all the way to the stiffest to bracket the test. Turns out it was perfect and the car was gliding through sweepers like it was on rails. We never even tried the middle stiffness bars. Oddly, this large 5/8” bar was what we would normally run on concrete, but the tightness of the test course overrode the grip factor.

With the car now dialed in, the Pro Solo started with rain. Without a co-driver, we were hurt by drying conditions for second drivers and started the weekend a way’s back. In the afternoon session, we came back to within a couple of tenths, but were still on the verge of not even making the cut for the Super Challenge. Since the Finale competition is so tight in all classes, the cutoff is usually less than 2 tenths.

As (bad) luck would have it, we got rain again overnight. And since we were the second group out on track, it looked like the second-driver scenario would play itself out again. Also, with drying conditions, it appeared that no one would go faster. In short, it looked like the final race was over before it began. Sure enough, the first three runs were no faster and we had resigned ourselves to second place. In dramatic fashion, with a last-minute pep talk and a “Hail Mary” final run attitude, we picked up a whopping half-second to win the class and secure a good seed into the Super Challenge!

In the Challenge itself, we used radios to keep abreast of cones and DNF’s on the opposing course, so as not to knock ourselves out. In the early rounds, less experienced competitors tend to make mistakes while pressing too hard. Sure enough, our competitors for the first two rounds hit cones, and the third round was a red light. In the end, we only lost one pairing, won the consolation and finished in third place for the event. This was easily enough to win the Overall title by a very wide margin. What a thrill!

This goal acheieved, the Solo II competition was just gravy. STS2 is still a supplemental class and so we would not be vying for a national championship. So we decided just to have fun and not get too stressed about it. With three days between the Pro Solo and the Solo II, the weather changed drastically. It got very, very cold. And the courses were much more open than in either the Test and Tune or the Pro Solo. Each would play a factor in our results.

We also took the time to have our shocks dynoed at the Koni support trailer. This is a wonderful service and many thanks to Lee Grimes and Jay Phizer for being there. As it turned out, one of our rear shocks had a failure in the divider piston and the nitrogen had all leaked out. Though they were rebuilt last year, we’ve put 25K hard trailer miles on the car this year so its no suprise the shock was blown. But it did get us wondering just how long the car had been this way and how the restored shock would affect the handling.

The first day of the Solo II, we were faced with cold tires, no co-driver, and large transition-heavy courses. In short, our previous setup work was all wrong. The car was impossible to drive so we changed sway bars on every run to try and fix it. By the final run, we were back to our usual asphalt setup and the car was decent. But we had dug ourselves a half-second hole that would be hard to overcome. Still, we were in second place in a class of almost 30 drivers.

Overnight, we found a co-driver whose car was acting up to help keep the tires warm. We also went to an intermediate bar setup that would be close to optimal for the sweeper-oriented course we were running. All of this worked to make the car much better and we only made one minor adjustment between runs to fine-tune. We lead early on, but once again it came down to the final run. It was a valiant effort, but we finished just 48 thousandths short of the winner over the two days. Still, we had lots of fun competing with the folks in this exciting new class.

Over the winter, we have a number of plans in the works to continue development. We’ll be looking into some different cold-air intake solutions and also try to squeeze a Mega-Squirt into the OE ECU housing. Should be challenging and fun, and we’ll take all of you along for the ride.

Join Free Join our community to easily find more project updates.
View comments on the GRM forums
Sponsored by

GRM Ad Dept

Our Preferred Partners