Searching for more power? A downpipe is an excellent source for horsepower! Since a turbocharger is essentially a pump, it’s important for the pipes leading up to and exiting the turbo to have unrestricted airflow. Factory downpipes generally are highly restrictive as they have catalyst material formed into "honeycomb" weaves. Exhaust gas must pass through these tiny "honeycomb" weaves on their way to the exhaust system thus causing a major exhaust flow restriction. It also causes turbulence after the catalytic converter which causes the exhaust flow to slow down.
When this M4 came to our shop for its appointment, it was bone stock with exception to the trunk mounted Aeromotion carbon fiber wing. Once it was on our lift we proceeded to install a full Akrapovic exhaust set-up, which included the Evolution titanium system along with the stainless steel catless downpipes. K&N performance air filters and a JB4 tuner were then installed under the hood to maximize this convertible's power output. Next we installed an RKP carbon fiber rear diffuser, which compliments the Akrapovic carbon fiber exhaust tips nicely, along with the M Performance carbon fiber front splitters & lip. You might notice that this F83 retains its chrome trim and orange reflectors; that's because the owner was explicitly focused on maximizing the car's power and aerodynamics instead of its exterior cosmetics. While this M4 convertible probably won't appeal to the more conservative BMW enthusiast, there's certainly no denying that it must be a blast to drive around Southern California. Enjoy.
Posted: November 26, 2014
Every year we participate in the European Car Magazine Tuner GP with one of our project BMWs. Having previously competed with a supercharged E92 M3 and a supercharged E86 Z4M, this was the first year we showed up with a turbo car. With our M4 putting down 559hp and 605ft-lbs tq at the wheels, we made some changes prior to the event to help this beast handle the race track.
While lowering springs are perfect for the street, the track demands a bit more. We opted for a set of KW Clubsport 2-way adjustable coilovers, which enabled us to dial-in the optimal settings for the highly technical Streets of Willow Raceway. We then installed a front/rear Brembo GT big brake kit for better stopping power and fade-free performance. Like many of our track-going customers, we installed a set of strong and lightweight 18" Apex EC-7 wheels wrapped in the event required Continental Extreme Contact DW tires.
Just like every other year we've competed, we drove our M4 to and from the event to prove that it's a double duty street/track weapon. Our driver, Jordan Yost of Yost Autosport, piloted the F82 and put down some awesome lap times. To get all the details you'll have to wait for the European Car Tuner GP issue to hit newsstands sometime early next year, but for now you can check out these exclusive photos and video from the event. Enjoy!