Key GTD adjustments highlight IMSA BoP tweaks

Image by Michael Levitt/LAT

Key GTD adjustments highlight IMSA BoP tweaks


Key GTD adjustments highlight IMSA BoP tweaks


IMSA has released its first Balance of Performance table for the upcoming WeatherTech SportsCar Championship season, with adjustments made to three of its four classes. The first BoP for 2020 will be trialed at the January 3-5 Roar Before the 24 test at Daytona International Speedway. Based upon the accuracies and inaccuracies found during that event, further adjustments will be made leading into the Rolex 24 At Daytona.

The most notable change is found in the pro-am GT Daytona category where sweeping modifications have been implemented to slow the class as a whole. RACER understands the motivation behind the GTD BoP adjustment involves creating more separation between the faster prototypes and pro GT Le Mans cars to ease passing maneuvers.

Filled with electronic driver assistance technology, the GT3-based GTD cars have, on many occasions, been nearly as fast as Daytona Prototype internationals, LMP2s, and GTLMs in braking zones and slower corners where passing often takes place. By dialing the pace of the GTD cars down by a modest margin, the goal is to reduce the number of clashes while overtaking occurs.

In DPi, Acura, Cadillac, and Mazda — the three remaining manufacturers — have adjustments to make, with Cadillac receiving the longest to-do list from the series.

  • Acura ARX-05: +2.0 liters fuel capacity, up to 78.0L
  • Cadillac DPi-V.R: +20 kilos, up to 950kg, +0.3mm air restrictor opening (more power), up to 32.2mm, +3.0L fuel capacity, up to 73.0L.
  • Mazda RT24-P: +5kg, up to 910kg, +1.0L fuel capacity, up to 80.0L.

In LMP2, the returning Riley/Multimatic Mk 30 chassis has received a number of Daytona-spec aerodynamic adjustments to match the other models. All LMP2s have been given the same fuel changes: +5.0L, up to 75.0L.

In GT Le Mans, the downsized class has seen three of the four manufacturers impacted by BoP, with the two new models from Corvette and Porsche receiving their first IMSA baseline settings.

  • BMW M8 GTE: No changes
  • Corvette C8.R: 1260kg minimum weight, 44.0mm air restrictor, 7400rpm redline, 2.25deg minimum rear wing angle with a 15.0mm maximum Gurney flap height, 0.88 minimum lambda number, and 89.0L maximum fuel capacity.
  • Ferrari 488 GTE: +1L fuel capacity, up to 88.0L, and an increase in turbocharger boost throughout the entirely of its rev range.
  • Porsche 911 RSR GTE: 1270kg minimum weight, 31.5mm air restrictors, 9400rpm redline, 1.2deg minimum rear wing angle, 0.89 minimum lambda number, and 86.0L maximum fuel capacity.

In addition to the class-wide slowdown, three new GTD models — two that are evolutions from last year’s cars — have been given their initial BoP tables to sample at the Roar.

  • Acura NSX GT3: -20kg, down to 1300kg, turbo boost reduction across entire rev range, -1.0L fuel capacity, down to 104.0L
  • Aston Martin Vantage AMR GT3: 1310kg minimum weight, 7200rpm redline, 0.91 minimum lambda number, and 104.0L maximum fuel capacity.
  • Audi R8 LMS GT3: -30kg, down to 1310kg, -1.0mm air restrictor (less power), to 39.0mm.
  • BMW M6 GT3: Turbo boost reduction from 4000rpms to redline, +1.0L fuel capacity, increase to 105.0L.
  • Ferrari 488 GT3: 1295kg minimum weight, 7500rpm redline, 0.90 minimum lambda number, and 93.0L maximum fuel capacity.
  • Lamborghini Huracan GT3: -1.0mm air restrictor (less power), to 38.0mm.
  • Lexus RC F GT3: -20kg, down to 1340kg, -2.0mm air restrictor (less power), to 38.0mm.
  • Mercedes AMG GT3: 1340kg minimum weight, 34.5mm air restrictors, 7700rpm redline, 0.88 minimum lambda number, and 101.0L maximum fuel capacity.
  • Porsche 911 GT3 R: -10kg, down to 1340kg, -5.0mm air restrictor (less power), to 38.0mm.


MX-5 Cup | Round 6 – Mid-Ohio