More on Autocross yesterday. Turbos and Autocross have always been an interesting mix, fun and challenging. With a supercharged autocross Miata like our 2007 I like to throttle steer through the course, around cones, precision use of every inch of the course is possible and rotation around features with all the extra power is an easy flick of the throttle. It is very different with the turbo.... dial up the power and then focus more on just roughly hitting my apex marks and otherwise keeping it somewhere between each side of the course. Placing it inches to the cones while trying to summon full TURBO power carries far more risks of stepping rear out and slapping that cone beside you. And so it was yesterday that Sean and I both did our best times in morning practice, in afternoon competition we both did our best times in our first 'warm up' run, and we both seriously slapped some cones during our subsequent runs. Great fun, perhaps even more fun to race than the supercharger, but also a lot more like a shotgun than a sniper riffle. With the supercharger in the car for the last event my challenge was just figuring best use of the power curve, control and placement of the car within the confines of the cones was not a challenge. But hey, at the end of the day our newly TURBO ND was fastest Miata by several seconds, beat all the BMWs too at this BMW CLUB Autocross event.
Now time to applaud the San Diego BMW CLUB. If within reach of San Diego, my TOP pick for Autocross big fun is the BMW Club. Their course designs are a mix of traditional autocross and full on race track. Yesterday included a double U turn that was so tight you had to get down to almost walking pace, but you were then rewarded with expanding radius full acceleration through two gears long downhill sweeper that sent our Turbo high into third gear and the tires just trying to hold on as the speed grew....onto the next rise and slam the breaks and catch the twitching car as you enter a Slalom. Will post video soon. So much Fun, such a great course, kudos to all involved!
As for COOL BOOST, happy to report that with two drivers flogging the car back to back our radiator temps were stable even as we regularly set and reset top time. Oil was still warmer than I want, broke 230 F despite massive oil cooler. We had challenges with cooland and oil temps at Laguna and that led to cutting the grille, though we have upped our oil cooling game per the prior posts after Laguna, we have now added an oil heating boost mechanism...the turbo itself...that makes our oil cooling challenge even higher than before. As time permits will make some more additional refinements to our cooling scheme.