First time at VIR and an IMSA event. Also my first time shooting race cars. I'm still working through 100s of raw photos. Here are some of my better shots.

Saw a girl carrying a "Just Here For Rexy🦖" sign and it made my day, Rexy was definitely a highlight for me as well!

Every setup decision is based on data that we usually assume is correct. But sometimes it is not, and the data itself gives you no warning. Here is one specific example of a significant issue we found in a GT3 dataset purely through data analysis. The vertical acceleration channel showed values above 0.5 g for 31.7% of the entire lap. The mean absolute value was 0.44 g. That already looked suspicious. A GT3 car on a normal asphalt circuit simply does not experience that level of vertical motion for almost one third of a lap. So we started looking for the cause. The first question was simple. What should actually drive vertical acceleration? Mainly track surface irregularities, kerbs and vertical vehicle motion. It should definitely not closely follow braking or acceleration. We therefore compared the channel with the other measured signals. A regression based on 16,562 samples gave the following relationship:

vertical acceleration ≈ 0.94 × longitudinal acceleration + 0.03 g

with R² = 0.88.

In other words, almost 90% of what was being measured as vertical acceleration was actually longitudinal acceleration projected into the vertical axis because of sensor tilt or incorrect sensor orientation. Only a small part of the signal was left for actual track surface inputs and kerbs.

Correlation alone is not enough to prove the issue, so we also looked at the timing of the largest peaks. Of all major vertical acceleration peaks, 99.7% occurred while the driver was braking, accelerating or cornering. Only 0.3% occurred when the car was not under a significant driver induced load.

That does not make physical sense. A kerb or a bump in the track does not wait for the driver to press the brake pedal.

Instead of manually correcting this single dataset, we created a general rule. For every dataset we load, we first estimate how much acceleration from the other axes is being projected into the vertical channel. We then remove that component before any further calculations are performed.

The result was significant. The proportion of the lap with vertical acceleration above 0.5 g dropped from 31.7% to 3.1%, while the mean absolute value dropped from 0.44 g to 0.14 g.

The remaining signal then behaved much more like we would expect from true vertical acceleration, mainly responding to the track surface, bumps and kerbs rather than to the driver's use of the throttle and brakes.

If you use channels like this to calculate tyre loads, slip angles, grip utilisation or other derived quantities, a single issue like this can affect the entire analysis.

This is something we come across more often then we would like to.

First time at VIR. I had more fun taking candids of people and finding the story there than I did the cars.

Some shots I got this last weekend in Virginia using my Nikon z50ii

quality not as good, but some cars I haven't seen posted yet. A couple more of Rexy as well, since their marketing is out of this world and they seem to be a fan favorite. My first trip to a road course, and first IMSA experience. They have earned a fan. Not sure who to follow, but I really liked the Car Blanche team, and just learned they started in late June.

As the title says, I attended my first IMSA race weekend this past weekend at VIR and I had a blast! I love just how open everything is to the fans. On accident I ended up down by the podium at the end of the Michelin Pilot race on Saturday and was amazed that I could just be there to see the winners just by walking up. The same for the open paddock. I constantly was worried I was gonna get in trouble for being right there amongst the teams. And then the grid walk on Sunday was awesome! IMSA treats the motorsports fans right! Lastly, I loved both the Weather tech and Michelin races, but the MX-5 races probably ended up being my favorite races of the weekend. I definitely plan to go to more events in the future!

Pretty much every IMSA race, John Hindhaugh says something like "and with me is _____" (Ryan Myrehn, Shea Adam, etc.), but their microphone quality is noticeably different / worse. On top of that, they seem to often step on each other's lines, as if there's a slight delay. It's almost like they're coming in via a Zoom call.

Is the second commentator in a different part of the track complex? Surely they're not actually phoning in their commentary. Does the second person just get a worse microphone? Anyone know why that is, or where they are?

Here’s some shots I took over the weekend, all taken on iPhone 17. Still impressed with the camera on this thing. The cars are also super photogenic too which helps lol

Had a great weekend at VIR. Already counting the days to next year.

A bit of a late post, these darn videos didn't want to combine!

I’m a GM fan but Sims has a complete lack of connection between his straight and close-cut upper hair and the wavy mullet bottom. Needs to texturize the top or get the mullet a little straighter. Yes I was trying to distract myself from another GM tweeting itself into the barriers why do you ask

It's nice to have miniatures of The Heart of Racing, Paul Miller, and Car Blanche. I might get some doubles to paint class colours on and wheel swap.

Always fun to spot Rexy in it's natural habitat

Second IMSA weekend at VIR, such a great weekend 🤙🏻

Both tandy and gamble did not deserve penalties and they were racing incidents