The twin-turbocharged 3.0 liter in line six-cylinder engine from the Alpina B3 S Bi-Turbo is also used in the B3 GT3. By amending the exhaust system and replacing the rear silencer the back pressure has been further reduced, increasing output in the B3 GT3 by 8hp. The direct petrol injected engine now delivers a total power output of 408hp at 6,000rpm and 540Nm of torque at 4,500rpm.