Before Hondata, before the A'PEXi Power FC, even before Speed Pro, there was ACCEL DFI. Pioneered by Eddie Kim and company at SoCal-based Dynamic Autosports, it was the first widely used standalone ECU adopted by Honda racers. The DFI box was key in helping drag race legend David Shih break the 10-second barrier. Honda guys could finally plug a laptop into a car and legitimize themselves as tuners. No more boost-dependent fuel pressure regulators or silly timing retarding boxes. Old-school tuners knew that once that little joke of a pixilated car made its way across the DOS-based screen they were on their way to making real power, which in those days was only about 350 whp but that's beside the point.
ACCEL's DFI was intended to be used on domestics, but the guys at Dynamic figured that if they built a harness to mate the system to Honda's engine sensors, they could have full control over fuel and ignition parameters, which incidentally is about all the DFI could control. The original system only worked on DOS operating systems. Keep in mind, this was a time when Windows was still in its infancy; the circuit board featured a whopping eight-bit processor-the same thing used on the original Nintendo system-but it did have 16 x 16 fuel and ignition maps and was able to scale itself based on injector sizes. This opened the door to larger fuel injectors than factory ECUs would be able to compensate for. Before the DFI reign, tuners were stuck using fish aquarium check valves as a means to divert positive pressure away from the OEM MAP sensors, which are designed to read vacuum, not boost. With the ability to use two- and three-bar General Motors' MAP sensors to register boost and distribute the correct amount of fuel to the engine, new power records were shattered month after month.
Yes, the MoTeC M4 was available during this time but was regarded as far too expensive for anyone in the Honda community. MoTeCs were reserved for multimillion-dollar race teams and could never be fitted to a Civic or Integra-or so the thinking was at the time. At $650 for the unit and about $300 for the custom harness, DFI pricing was just right for the times. Oh how times have changed. There are a number of engine management choices now and money no longer seems to be the main concern. Still, it all started with ACCEL's little box that made history.