E92 M3 cracks 400 horsepower at the wheels with GIAC tune on 91 octane pump gas - Gains ~50 WHP from tune and bolt ons
These are some very impressive results. The M3 used is a DCT as which has slightly higher drivetrain losses than the manual making cracking 400 whp in naturally aspirated form on 91 octane quite the achievement. The baseline for the M3 was 351 whp, spot on. With an air filter and under drive pulley it hit 367 wheel horsepower. With the addition of a GIAC tune and exhaust including X-pipe the car hit 400 whp for a gain of 49 horsepower at the wheels, very nice. The car will be tested next with an Evolve tune and we will report how it compares to the GIAC.