DTM BoP Zandvoort 2025: Why Porsche is getting a much bigger restrictor

(Motorsport-Total.com) - The Balance of Performance (BoP) for the DTM weekend at Zandvoort ( all information on TV times, stream, etc. ) has some changes compared to the Lausitzring. The impact will also depend on the weather, as the forecast rain could put the significance of this into perspective. It is noticeable, however, that the Porsche 911 GT3 R has been fitted with a significantly larger restrictor.

Instead of the previous 38 millimeters, the Manthey team will be able to switch to an air restrictor with a diameter of 41.5 millimeters in the Netherlands. This is 3.5 millimeters more, which should have a very positive effect on engine performance. This is a reaction to the first two weekends, in which the Manthey Porsches consistently finished in the lower positions in the top speed rankings.

And this despite the fact that Ayhancan Güven and Thomas Preining took the win and third place in Oschersleben and Preining also fought for the lead on Sunday in Lausitz after an early retirement.

Less weight for AMG, more for Lamborghini

The move was carefully coordinated with Porsche: To compensate for the increase in power, 20 kilograms of ballast are being added to the weight box compared to Lausitz. By comparison, at the GT World Challenge Europe Sprint Series (GTWCE), which visited Zandvoort two weeks ago, the Porsche had a 38mm restrictor on board, but was 40 kilograms lighter.

While the Ford and Audi were classified exactly the same as in Lausitz, the Mercedes-AMG teams are allowed to unload ten kilograms. The car also weighs five kilograms less than in the GTWCE at Zandvoort, and its lambda value is 0.03 lower, which translates to slightly more power than in the SRO series. However, tire heating is not permitted in the DTM, which is less beneficial for the car.

The Lamborghini will be five kilograms heavier than at Lausitz, after the unfavorable classification on Saturday was corrected and weight was offloaded. Compared to the GTWC, the Huracan GT3 Evo2 is also five kilograms heavier.

Will the BMW be under control this year?

The BMW, which has been in great shape recently, didn't change its weight, but the boost pressure was. It was significantly reduced at lower revs, but increased at higher revs. In this regard, the comparison with last year is also interesting, as hardly anyone could compete with the M4 GT3 in a one-on-one battle.

The 2025 Evo version of the car will receive even more boost pressure at lower revs than in 2024, but slightly less at higher revs. In addition, the minimum angle of the rear wing is designed to prevent an excessively significant top speed advantage.

As in the previous year, those responsible for the BoP at Zandvoort face a major challenge. Because the modified schedule means that the qualifying sessions, which are so important in Zandvoort, are held before the first race, important experience and data are missing. This, incidentally, was the reason why the BMW's BoP was improved last year after the poor first qualifying result, and the car was then too strong in the race.

SRO reacts to McLaren's favorite track from last year

Speaking of strength: The McLaren, which had by far its strongest weekend at Zandvoort last year thanks to Clemens Schmid's second place on the grid and fourth place in the race, was rated significantly lower compared to the Lausitzring. 30 kilograms of ballast had to be loaded, and the boost pressure was also reduced slightly.

This also makes the 720S GT3 Evo 15 kilograms heavier, and the boost pressure in the midrange is slightly lower than on Saturday a year ago, when Schmid was on top. The fast corners, rough asphalt, and flat curbs suit the car.

Compared to the Lausitzring, where Jack Aitken won, the Ferrari adds 15 kilograms of weight – boost pressure has been significantly reduced in the mid-range. And the Aston Martin, which set the fastest time in the test more than two weeks ago, also has to cope with lower boost pressure.

DTM BoP Zandvoort 2025: Aston Martin: 1,280 kg/1.37 - 1.97 bar (boost pressure) Audi: 1,315 kg/2 x 36.5 mm (restrictor) BMW: 1,300 kg/2.10 - 2.69 bar (boost pressure)

Ferrari: 1,315 kg/1.0 - 2.48 bar (boost pressure)

Ford: 1,300 kg/2 x 38 mm (restrictor)

Lamborghini: 1,345 kg/1 x 50 mm (restrictor)

McLaren: 1,310 kg/ 1.10 - 1.78 bar (boost pressure) Mercedes: 1,335 kg/2 x 34.5 mm (restrictor) Porsche: 1,330 kg/2 x 41.5 mm (restrictor)

Aston Martin: -0.04 to +0.00 bar (boost pressure) BMW: -0.08 to 0.00 bar (boost pressure) Ferrari: +15 kg / -0.05 to +0.02 bar (boost pressure) Lamborghini: +5 kg McLaren: +30 kg / -0.02 to +0.00 bar (boost pressure) Mercedes: -10 kg

Porsche: +20 kg/+3.5 mm (restrictor)

No changes to ground clearance, lambda and rear wing angle.

DTM BoP Lausitzring 2025 (Sunday): Aston Martin: 1,280 kg/1.37 - 1.97 bar (boost pressure) Audi: 1,315 kg/2 x 36.5 mm (restrictor) BMW: 1,300 kg/2.10 - 2.69 bar (boost pressure) Ferrari: 1,300 kg/1.0 - 2.48 bar (boost pressure) Ford: 1,300 kg/2 x 38 mm (restrictor) Lamborghini: 1,340 kg/1 x 50 mm (restrictor) McLaren: 1,280 kg/1.10 - 1.78 bar (boost pressure) Mercedes: 1,345 kg/2 x 34.5 mm (restrictor) Porsche: 1,310 kg/2 x 39.5 mm (restrictor)