The wait for the all-new BMW M3 Sedan and M4 Coupe is almost over as the automaker has confirmed the two high-performance models will debut in mid-September.

This means there’s not much time left for testing, which is why BMW M is running on all cylinders at the moment performing driving dynamics tests under racetrack conditions. This is a crucial phase of the series development process and BMW M is not just relying on the Nürburgring Nordschleife for the job.

The automaker is currently testing camouflaged 2021 M3 and 2021 M4 prototypes on the 3,670-meter (2.28-mile) long Sachsenring, the long-standing venue of the German Touring Car Masters (DTM) racing series. The challenging track’s hairpin bends, long straights and the downhill passage before the Queckenberg bend are ideal conditions to fine tune the longitudinal and lateral driving dynamics of the two cars.

Watch: 2021 BMW M3 Hits The Nürburgring In Official Teaser Video

2021 BMW M4 Coupe

Alongside the photo gallery of the camouflaged prototypes, BMW has also confirmed engine specifications of the 2021 M3 and 2021 M4, which promise “a significant increase in performance” over the predecessor models. That’s because the new models offer increases of 49 PS (48 HP) in base spec and 60 PS (59 HP) in Competition guise over the outgoing BMW M3 and M4.

Power comes from a twin-turbocharged 3.0-liter straight-six engine sourced from the BMW X3 M and X4 M SUVs. There are two performance levels to choose from. In base specification, the unit delivers 480 PS (473 HP / 353 kW) and it comes with a standard six-speed manual transmission and rear-wheel drive, much to the delight of BMW M purists.

There is also the choice of a Competition model with 510 PS (503 HP / 375 kW) and 650 Nm (479 lb-ft), offered as standard with an 8-speed M Steptronic transmission with Drivelogic and rear-wheel drive. Later on, the M3 Competition and M4 Competition will also be available with the latest version of the M xDrive four-wheel-drive system.

2021 BMW M3 Sedan

“For customers who prefer a puristic performance experience and particularly intense interaction with their vehicle, the model variants with a manual transmission constitute an offer that is unique in this segment,” explains Dirk Häcker, head of Development M Automobiles and BMW Individual. That is true as rivals from Mercedes-AMG and Audi Sport do not offer a manual option.

Elsewhere, the new BMW M3 and M4 will feature an M-specific suspension setup, as well as “comprehensive innovations in the areas of drive, wheel suspension, springs, dampers and braking technology”.