There’s Great Grip…Until There’s Not — Observations from the IMSA SportsCar Weekend at Road America

The DPi Acura looked pretty long, but not as long when compared to the current GTP cars. [Pete Gorski Photo]

by Pete Gorski

“Firsts” don’t happen every day at a track with sixty-eight years of history like Road America, but the IMSA weekend featured a big one and a few “first time in a long time” moments.

Of course the big “first” was the inaugural visit to Road America by IMSA’s new-for-2023 hybrid GTP class. Not to slag the previous DPi era, but there’s a palpable buzz (no hybrid pun intended) surrounding these new cars. Porsche and BMW are back in the top class which is alway a good thing for prototype racing. And so far, teething pains have been relatively light; the threat of retirements due to new technology issues haven’t really manifested. More on the GTPs later.

One of the other “firsts” is playing out over the course of the season — the first time in 28 years the track has been paved and the impact the new surface has on each series as it experiences it for the first time. As we’ve heard all season long, teams can throw out their “books” because anything they knew about the 4.048-miles of pavement no longer has any relevance. But what’s been unexpected is how each series’ perspective has changed as the season progressed.

Fan-favorite Sexy with some 911 cousins. [Pete Gorski Photo]

So many GTs… [Pete Gorski Photo]

Victory smells like hot brakes and champagne. [Pete Gorski Photo]

On this lap, the 718 was ahead of the BMW M4s. The next lap…(shrug)? [Pete Gorski Photo]

Your GTP podium. [Pete Gorski Photo]

The current Acura GTP heats up the front brakes on the way into T5 during Friday practice. Notice the extra length compared to last year’s car. [Pete Gorski Photo]

The Porsche 963 wears a clean design, but the duckbill front end is a little disappointing. [Pete Gorski Photo]

The DPi Acura looked pretty long, but not as long when compared to the current GTP cars. [Pete Gorski Photo]

The best looking of the bunch. [Pete Gorski Photo]

The front end may be polarizing, but how can you not like those taillights? [Pete Gorski Photo]

The BMW M Hybrid V8 is undeniably distinctive. [Pete Gorski Photo]

The #6 963 blasts into T3 during qualifying. [Pete Gorski Photo]

Two wings are better than one…apparently. [Pete Gorski Photo]

The calm before the storm. [Pete Gorski Photo]

The SVRA Spring Vintage Festival was the first “magnet” series to run on the new pavement and the reaction from drivers was almost universally positive. No bumps, consistent, very little tire wear… MotoAmerica was next, and they were setting track records while praising the new surface.

But as the heavy pro series (and that’s not a NASCAR joke) have rubbered in the track with their super sticky tires, grip that had been consistent from edge to edge has shrunk to a single groove. “It’s great on line, but off it’s a skating rink,” or words to that effect, have been heard regularly with each following visit.

Whether the development of (or reduction to) a single groove is a good thing or bad thing is a matter of personal perspective. There’s definitely a vicious circle thing happening, where the grip is so strong on line that nobody wants to run off line, which makes the current line even more grippy because everybody is running there. But there’s one aspect of the new pavement that on the surface (ha!) seems like a good thing, but is causing some trouble.

Cornering speeds are up. That’s great, right? However, because of that, cars seem to be running wide both more often and in places they never used to. More cars have had trouble exiting the Carousel during the past two events (NASCAR Xfinity and IMSA) than in the previous 10 years, or so it seems. (Not much data to be mined on that.) The clouds of dust that rise from the now-grassless area bordering the curbing at the exit of Turn 10 would seem to support the assertion, as would the number of cars hitting the barriers from the exit to the base of the bridge that leads to The Beach.

Let’s get back to the GTP class. We did a story when the cars first debuted that focused on how racecars don’t have to look good to be successful, but it’s nice when they do. After three days of watching and photographing the four models, here are my observations — your mileage may vary.

Sometimes seeing a car in all three dimensions provides a perspective that changes your opinion. Not this time, at least in regard to the Acura. I wasn’t a fan of the Acura ARX-05 DPi’s looks and seeing the new version up close has not swayed me. The BMW M Hybrid V8 is undeniably distinctive, but not really beautiful. That said, the taillights are a great bit of design. The Porsche 963 suffers a little bit from what I’d describe as a duck-bill front end, especially in profile. I’m sticking with my assessment that the Cadillac is the most sinister of the bunch, even in non-Galactic Empire livery. And, as the only atmo engine out there, it sounds the best. Turbos may be a great way to make power, but beyond the spooling whistle, they muffle engine sounds to a disappointing degree.

Beyond all those subjective aspects, the cars are faster and in another YMMV situation, longer. The two carry-over manufacturers’ DPis rode on wheelbases of 155.5 inches (Cadillac) and 118.3 inches (Acura). The GTPs are all pegged at 123.9 inches. But overall length is a different story. The Porsche 963 is listed at < 5,100mm (200 inches), the maximum allowed by the rules, as are the Cadillac and the Acura. The BMW is 4,991. So length is up by 12 inches or so. There has been a discussion recently about how long Formula One cars have become. The explanation is that all the extra MGU apparatus has to fit somewhere, and the engineers don’t want the cars to get wider, so they get longer. (There’s an aero incentive too.) It makes sense that with hybrid power units, the GTPs would get longer. But they look almost awkwardly long (as do current F1 cars), like turning a short bus. For reference, my personal favorite from the aforementioned “beauty” article, the Porsche 917, rolled on a 90.5 inch wheelbase with a length of 163 inches. The 962? 104.3 inch wheelbase and 189 inch length. All this extra length explains why the cars look so slow and ungainly in slow-speed corners, like Long Beach’s hairpin. But don’t misunderstand, the GTPs still put on a great show. And with the addition of the SC63 from Lamborghini next season, excitement and competition levels should remain high. While the WeatherTech Championship was the headline series, the Mazda MX-5 Cup, Lamborghini Super Trofeo series, and Michelin Pilot Challenge kept the track packed with action all weekend long. I mentioned last week how odd it is to hear a single-make series (Porsche Carrera Cup) come hustling past you when you’re used to a variety of engine notes, and here were two more! The Mazdas sound much more raspy and buzzsaw-like in race tune than you’d expect; the Huracáns make a deeper (obviously) rumble, with a cammy overlay. It’s unfortunate that TV needs necessitated running the WeatherTech race early in the morning, bumping the Michelin Pilot Challenge race to the afternoon. The fans who stayed to watch were rewarded with a diverse field of GS and TCR cars running in close contact for much of the two hour race. The last thirty minutes produced multiple position changes between the BMW M4 GT4s from Turner Motorsports and Random Vandals Racing and the Porsche 718 GT4 RS of NOLASPORT. Just when it seemed like the order was set, the pack would burst into view under the Corvette bridge led by a different car than the last time. And in case you were wondering, yes, the Hyundai traction control system still sounds like somebody is stepping on a dog toy every time it engages.

Pete Gorski

I’ve been a race fan from the first time my Dad put a slot-car controller in my hand. That was back in the 1970s, and in the intervening years, I’ve spent hours watching racing, photographing racing, and for the past seven years, writing about racing. My work has appeared in Victory Lane magazine and SpeedTour Quarterly, along with the Visors Down Motorsports Photography Facebook page.

www.gorskiphotoservices.com

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