The 135I VR390 horsepower kit really starts to open up your N54 turbocharged engine. By adding catless downpipes and a performance catback exhaust system, the turbochargers are able to flow freely without any backpressure. By adding these exhaust components to the car, the horsepower will go up by 30hp giving you more response when the gas pedal is hammered. The Agency Power catless race downpipes are 304 stainless steel designed to bolt up to your stock turbochargers. They are larger in diameter then stock to help improve turbo performance. With the downpipes installed, the turbos are much more audible however this does not affect cruising speed cabin noise. In addition to the downpipes, we add our Agency Power midpipes and axle back exhaust system. The full catback exhaust includes our new Agency Power center race pipes with resonators. The axle back features a high flow muffler, titanium tips, and all polished 304 stainless steel. This exhaust system improves the overall performance by reducing back pressure and not creating substantially more noise. With the addition of the JB3 plug and play ECU and Injen cold air intake, we were able to take this vehicle to 390 horsepower at the crank. With a drivetrain loss of 10-15%, this is nearly a 80 horsepower gain!
We obtained our numbers using 91 octane pump fuel. Because the JB3 plug and play ECU has map switching abilities, horsepower can increase to over 400hp with the addition of 100 octane race fuel. For more on JB3 Map Switching, visit N54 Tech here. For further questions on this power kit for your BMW, contact one of our BMW specialists.
BMW 135I VR390 Kit Includes:
- JB4 Plug and Play ECU
- Injen Cold Air Intake Kit
- Agency Power Race Downpipes
- JB4 CEL Eliminator
- Agency Power Race Midpipes
- Agency Power Axle Back with Ti Tips