The other GTP manufacturers are reeling in Aston Martin a little bit: BoP breaks for almost every manufacturer ahead of the upcoming round at Laguna Seca Raceway in Monterey.
Following the tight corners of Long Beach, where heavier weight might not be as much of a problem, the IMSA WeatherTech Sportscar Championship heads to the hilly Laguna Seca Raceway as its next destination with a slightly tweaked Balance of Performance (BoP).
Every manufacturer except Aston Martin, who is already at the best possible limit, will receive a more advantageous power-to-weight ratio compared to the Streets of Long Beach.
In particular, the Porsche 963 lightens from its mandated 1,100 kilogram weight but remains the heaviest GTP car at 1,084 kilograms and 480 kilowatts of power below 190 kph.
Crunching the numbers, the following picture emerges when calculating power-to-weight ratio below 190 kilometers per hour:
Aston Martin Valkyrie - 1.981 kg/kW BMW M Hybrid V8 - 2.034 Cadillac V-Series.R - 2.045 Acura ARX-06 - 2.079 Porsche 963 (2025) - 2.107 Porsche 963 - 2.259
Aston Martin remains at the most advantageous level, one that the Valkyrie LMH has enjoyed since Sebring. The 2026 Porsche 963 is still held back in low-speed BoP after its higher rating for the 2026 Rolex 24.
Compared to Long Beach, the following changes emerge:
Acura ARX-06 -0.038 kg/kW Porsche 963 -0.033 Cadillac V-Series.R -0.025 BMW M Hybrid V8 -0.023 Porsche 963 (2025) -0.016 Aston Martin Valkyrie +-0.000
Here, Acura gets the biggest break. While only receiving a 3-kilo weight break, the ARX-06 is allowed 7.8 kilowatts more power, leading to more punch out of tight corners like Andretti Hairpin, Corkscrew and the final corner at the Laguna Seca Raceway.
The 2026 Porsche receives a 0.033 kg/kW better power-to-weight ratio, which, after its monumental hit ahead of Long Beach, still puts its weight far above all other GTP cars.
The two Dallara-based LMDhs of Cadillac and BMW receive a smaller break, with the 2025 Porsche receiving the smallest improvement following an encouraging performance at Long Beach.
In comparison to the BoP at Laguna Seca Raceway in 2025, the following picture emerges. Keep in mind that all LMDh cars except the 2025 Porsche have been updated over the winter:
Cadillac V-Series.R -0.099 kg/kW Porsche 963 (2025) -0.056 Acura ARX-06 -0.033 Aston Martin Valkyrie -0.004 BMW M Hybrid V8 +0.042 Porsche 963 +0.096
Cadillac gains nearly 0.1 kg/kW compared to last year, with the 2025 Porsche also receiving a big break. BMW, which had a very favorable power-to-weight ratio of 1.992 kg/kW back in 2025, has been reeled in again and brought to a similar level with the Cadillac V-Series.R.
Of course, the 2026 Porsche 963 is still way above all power-to-weight ratios seen in 2025 and so receives the biggest penalty compared to last year.
After the 190 kph threshold, the picture begins to swing in the completely different direction: From 200 kph onwards, the Porsches receive the most favorable BoP, of course behind the relatively draggy Aston Martin Valkyrie, which is still clearly in front:
Aston Martin Valkyrie - 1.981 kg/kW Porsche 963 (2025) - 2.079 Porsche 963 - 2.085 Acura ARX-06 - 2.087 Cadillac V-Series.R - 2.089 BMW M Hybrid V8 - 2.100
For the first time this year, BMW gets the least favorable power-to-weight ratio, albeit the five LMDh cars are being kept inside a small corridor of 0.021 kg/kW, as IMSA had envisioned over the winter.
Porsche 963 (2025) -0.044 Porsche 963 -0.031 Acura ARX-06 -0.010 Cadillac V-Series.R -0.006 BMW M Hybrid V8 -0.001 Aston Martin Valkyrie +-0.000