The RACER Mailbag, March 15

The RACER Mailbag, March 15

Insights & Analysis

The RACER Mailbag, March 15

By ,

Welcome to the RACER Mailbag. Questions for any of RACER’s writers can be sent to Due to the high volume of questions received, we can’t guarantee that every letter will be published, but we’ll answer as many as we can. Published questions may be edited for length and clarity. Questions received after 3pm ET each Monday will appear the following week.

Q: There are more questions and gaps in the story of Meyer Shank Racing cheating with the minimum tire pressure numbers. As I watched the end of the race, it sure gave the team enormous performance benefit resulting in their victory — which after learning about the infractions, to my surprise IMSA decided to uphold. 

What way do tire pressure data normally get communicated from the race car to IMSA? Live telemetry or on a USB stick or laptop download well after the event? Isn’t this data handled in a closed system if live? How can that be tampered with — in the software? Can manual entry be ruled out or not? 

When did HPD learn about the violation and how soon after the race did they became aware? Was HPD conducting shaker rig testing and comparing tire data coming from Wayne Taylor Racing, for example?  

Mike Shank needs to confess who actually came up with this idea: really Ryan McCarthy on his own, or was it the team principal who wanted to do this but used McCarthy as a sacrificial scapegoat? 

Why did the car not get disqualified as a minimum? Is this because NASCAR owns IMSA and it is their policy that whoever crosses the finish line first keeps the position regardless whether achieved by means of cheating? What do other teams and manufacturers think about this?

Adam Lipcse, Toronto, ON 

MARSHALL PRUETT: If you want a deeper dive, Adam, take a listen to my The Week In Sports Cars podcast I do with Graham Goodwin; it was the opening topic last week.

A couple of things: The violations were twofold. First was the setting of tire pressures below Michelin’s minimum for the event. The second was manipulating the tire pressure monitoring system (TPMS) data leaving the car via live telemetry which was being received by IMSA.

I’m told the data systems on the GTP cars are indeed closed in terms of teams and manufacturers being able to fudge numbers on the regulated items; the TPMS system falls outside of this and, as we learned, was an area where an offset could be applied in the software to fake the tire pressure numbers fired across every second through telemetry.

I can’t say on the exact date and time it was discovered, but anecdotally, I’ve heard it was found and/or reported by HPD to IMSA about a week after the race.

I was not a fan of the statement distributed by MSR pointing to McCarthy, who’s listed as the team’s technical director on his LinkedIn profile, as the proverbial “lone gunman.” Having spent many years of my life on teams exactly like MSR in IndyCar and IMSA, I just can’t think of how one person could concoct and execute this plan in complete isolation.

Teams have one to two tire technicians who handle every aspect of tire usage, including the setting of tire pressures. That’s not something the technical director would do once, much less a dozen-plus times over a 24-hour race. So instructions to set the pressures low had to be given, and that now involves multiple people.

And even if the tire techs had no clue about the pressure settings being lower than the rules allowed, there’s no way you send drivers out on cold and under-pressured tires without telling them to be careful — extra careful — until they got up to temperature. If you’re running a pound or two low on pressures, you’re also needing to adjust ride heights, at a minimum, or else you’d be dragging the ground. And there are other chassis settings you’d need to adjust to compensate for running low pressures.

Trust me, I’ve had a lot of race engineer friends, team owners and team principals reach out and either ask for details or share their thoughts on this, and not a single one has said they believe one person, and one person alone, acted in isolation from the rest of the team. I want to believe it was one bad actor, but it makes no sense to me or other racers. Others had to be involved, but knowing the majority of the crew, I’d put good money on them being unwitting participants.

What’s more likely is the others were unknowingly involved; changes to the pressures, chassis and driver prompts being given without explaining the finer details. Truthfully, and I say this as a former pro mechanic, we do a lot of following instructions — raise the ride height four flats or take 1.2psi out of the front tires, or whatever — without there being a dialogue back and forth as to the what and why. It’s fairly militaristic in that way: You don’t question the orders you’re given; you follow the orders you’re given.

Yep, this is a straight NASCAR deal (NASCAR owns IMSA for those who weren’t aware) where they refuse to take the winner’s name off the trophy. They’re big on whomever folks saw in victory lane will stay the people who celebrated in victory lane.

Q: MSR just got penalized by IMSA for manipulating the minimum tire pressure data and running below the threshold set by Michelin. The penalties seemed pretty stiff. How big of an advantage did this provide? Was it enough of an advantage to influence the outcome of a race?

Brian Henris 

MP: Big, Brian, which is why they did it. I listened to a number of GTP drivers and engineers at Daytona tell me that Michelin set the minimum tire pressure threshold too high — above where the tires would be happiest and offer the best balance and feel — but they were bound by the rules to operate above the minimum.

MSR’s Acura was a rocket at every step of the event, and in the race, it was not only the fastest car, but it was notably faster than its stablemate Wayne Taylor Racing Acura. Nobody could explain why the MSR Acura was so unbeatable. This tire pressure revelation was the “AHA!” moment for everyone else in the class. Just so damn disappointing. What will be interesting is to see how they perform at Sebring.

Can the Meyer Shank Racing W/Curb-Agajanian Acura ARX-06 keep the same margin over its WTR stablemate — and everyone else — at Sebring while riding on the same amount of air? Michael Levitt/Motorsport Images

Q: I just saw the article about Porsche and Lambo getting some BoP help for Sebring, and saw some teams already pulled out due to BoP issues. It sounds like some teams were shifting focus away from IMSA races. Just looking at the optics of this, it looked like teams pulled out of Sebring and IMSA went, “Oh OK, we will change the rules!” Which is not a great look. I guess I am just confused as to why BoP exists? When the motorsport world is all about innovation and technology, wouldn’t BoP cause manufacturers to not invest in tech and development? Especially when you might get a larger restrictor thrown on your car and be a second or more off the pace, what is the point of developing a high-tech fast car?

I know I am preaching to the choir here about BoP, but as a relatively new sports car racing fan, I am so curious about how this all works.

Mike, Michigan

MP: This was an outlier in terms of BoP and Porsche’s new 911 GT3 R model, and frankly, IMSA and Porsche failed each other. IMSA refused to believe the new 992-based GT3 car was as slow as it was in pre-season testing, and insisted — to the great frustration of the many Porsche GTD teams using the new car — that the dire lack of speed was a ploy to receive an advantageous BoP. The cars were so slow, that was the only thing that made sense.

In reality, and this is where Porsche failed, the new car is a dog compared to its predecessor. If you’re looking at things from IMSA’s perspective, it just doesn’t seem conceivable. But that’s precisely what we’re dealing with: The 2023 911 GT3 R left the factory in a poor state of development and readiness to compete with the other GT3 models.

When confronted with its dire lack of speed during BoP data gathering at Daytona in early December, IMSA couldn’t and wouldn’t believe the car itself was at fault because, well, when was the last time Porsche came up so short with a new GT3 model? Never, basically. And so now, with clear evidence that the 911 GT3 R needs extra BoP love to measure up to its rivals, its Sebring BoP settings should bring it into the competitive conversation without giving it an advantage.

Porsche has a lot of work to fix its shortcomings, just as Lexus did when it developed multiple versions of what became its original RC F GT3 which has become a race-winning beast. IMSA won’t keep giving Porsche favorable BoPs forever to compensate for the car’s obvious deficiencies, so watch this space.

Q: There has been much discussion of the Rolex 24 scandal since you broke the story last week. Many, myself included, have opined that watches should be returned. It may be a very good gesture for Mike Shank and his team to be the ones to return them voluntarily. I have to believe that owning or wearing the coveted watch will never feel quite right in light of how it may have been won.

Brian Bristo

MP: I think of all the Tour de France cyclists who were caught cheating and had to return their medals. Only seems fair to return the Rolex 24’s VERY expensive version of a medal if you’re caught cheating. How’s this: It would take BALLS to wear those Rolexes in public, right?