Breaking Records with the Solo Motorsports 624HP Time Attack BMW 135i


The OEM center / core support was trimmed and cut to make space for the massive IC.


Keeping the intake charge cool is important. Keeping the oil cool is important-er… Here, Solo employs a dual Setrab oil cooler setup to help keep the life-sustaining lubricant at the proper temperature.

Not pictured is the CSF radiator which keeps the coolant happy, too.


With a denser, more fuel-filled boosted intake charge comes the need for more performance in the ignition system, too. Precision Raceworks makes a complete plug-and-play ignition system for the BMW N54.

According to Precision Raceworks, the system incorporates a coil of their own design that is matched to the BMW DME’s expectations. The OEM system utilizes an IGBT (Insulated Gate Bipolar Transistor) that drives a “dumb” coil. The commonly used LS coil is, according to PR, a “smart” coil that does not take a simple input signal. Instead of doing all kinds of hacky things to the ignition setup and possibly compromising reliability and daily drive-ability, PR designed a coil that works with the DME IGBT driver and is designed to work with the factory DME coil dwell time, all while delivering more spark energy.

It all seems to be working, based on the dyno figures and the car’s performance.


A Fuelab FPR is used to maintain fuel pressure for a set of secondary injectors.

The N54 is a direct injection engine that features a super high-pressure injector. The aftermarket for direct injection is still nascent, so choices are limited. In most cases, people use some kind of port-mount retrofit kit to get more fuel when the factory system is maxed out.

The Solo 135i uses a Fuel-It! E-Series port injection kit in order to get more go-juice into the cylinders. Fuel-It! Provides several methods of integrating with the factory DME, and, in Solo’s case, they use the Split Second AIC6 without any intermediary unit, since they can program the DME themselves. The car also features dual Walbro 450 fuel pumps mounted in the factory BMW tank, one for each fuel system. Ignite 114 race fuel is Solo’s choice.

Once all of the fuel is turned into noise, heat, and power, it passes through a Clutch Masters twin disk clutch. The rest of the motor is otherwise stock – for now. Solo has a completely built N54 in the works with some extra fancy bits, so stay tuned for a future update.


The FireSense fire system has a couple of nozzles installed in the engine bay. One right behind the motor, pointing at portions of the fuel system.

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