Mid Ohio, Part 1: Test Day at Pineview Run

The Occam’s Racers team will be racing at Mid Ohio on 10/18-20 with AER. The main team is Mario Korf (me), Pat Cornwall, and Alyssa Merrill. Pat races regularly with a BMW league, and he’s been on the Occam’s team twice before. He’s a fast driver, a good mechanic, and you can’t ask for a better teammate. Alyssa was one of the drivers at the Watkins Glen aero tests. Her background is sim racing, and this make her racecraft very impressive, and her online speed somehow translates to the real world.

I’ve been looking for a fourth driver for this race, and found one: Sonny Watanasirisuk. If you follow Miatas, you probably know the name, he works for 949 Racing has won many a race and championship, and is a pro driving coach. Sonny will be joining the team primarily as our coach. Who am I kidding? He’s our ringer. I’m super stoked at this development, and I’m sure it will result in some humble pie, as well as a bunch of speed and setup secrets which I will share with you all. (Or not. Muah ha ha ha.)

But first things first. We have a car hasn’t been run since the WGI tests, and we wanted to address the understeering problem we had there. So we put the rear sway bar back on and corrected the negative rake. There were other things to do, like new shackle-style motor mounts, which should keep the header from hitting the trans tunnel. It was making an awful thumping sound and was really disconcerting.

With these and other details done, we loaded up and headed to Pineview Run for a team test day. I’ve been driving my 1.6 Miata at Pineview a lot, and the first thing I noticed about the race car is that it steers way better, probably because of more caster. On the other hand, the brake bias is way off. The front brakes are the larger 99+ Sport model with Porterfield RE4 pads, and the rear are stock 94 brakes with StopTech pads. This makes for a very grabby and front biased setup that will need to be corrected with a prop valve and possibly a pad change before the race.

We each took two turns in the race car, and logged data with an AIM Solo. This allowed us to compere dick sizes lap times, and see where each of us is fast. I had the fastest average lap (I have a lot more laps around Pineview and can drive it consistently), but they both put in laps that were outright faster than I could. It’s good to have teammates that are faster than you are. What was surprising is that while our times were fairly close, we have different driving styles. But more on that another time.

I also invited my 24 Hours of Lemons teammate, Tom Pyrek, down to Pineview Run, and he brought his racing minivan. Tom got into the Miata for a few laps, which was surprising because he doesn’t like Miatas. Alyssa got to drive his Neighborhood Trolley minivan in exchange, which was pretty dope. Then it started to rain, and the fun really began.

Here’s a couple videos of Alyssa in her NB Miata and Tom in the minivan. Rain is fun!

Alyssa on bald NT01s in the rain.
Tom in the Neighborhood Trolley, or boat, as it were.

In all, the test day went great. We had a lot of fun in the dry and wet, and the race car seemed much more balanced. (No video from the race car, sorry.) We’ll have to sort out the high speed handling when we get to Mid-O.

To get back to Sonny, he recently won the TT6 race at Mid Ohio, and I used his 1:40.7 lap time on the Pro Course to correct some values in OptimumLap. Based on the G values I saw in the video (around 1.3 g steady state cornering with higher spikes, but I’ll settle on 1.3 g) and rough Cl and Cd data (.48, .45), I was able to get the same lap time by changing course grip to 95%.

Sonny doing it at Nationals

Based on the data corrections, OptimumLap says my car should be capable of a 1:41.6 on the Pro Course (with Sonny behind the wheel). AER is using the chicane, which adds probably two seconds, so a projected lap time is more like 143.5. This is all preliminary guesswork, but time will tell. Literally.

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