Okada Projects has gained popularity among automotive performance tuners across the globe with their highly effective Plasma Direct ignition system. The Plasma Direct system improves spark energy over factory coilover plug applications and has been proven successful in numerous vehicles campaigned in time attack and Super Lap Battle race events throughout Japan. One example is the ultra-competitive M-Speed R34 GT-R, which battled against Japan's elite tuner cars at the season finale time attack in December. The M-Speed Skyline, equipped with the Okada Project Plasma Ignition, dominated the circuit and took the title of '07 Tsukuba Time Attack champ as the canary yellow GT-R blasted an amazing 54.4 seconds at the Tsukuba circuit.
At a time and age when horsepower rules the street, the demands of delivering sufficient fuel and spark becomes a critical factor when looking to increase horsepower and torque beyond the factory ignition's status quo. The most common occurrences among high-horsepower vehicles are typically intermittent misfires, which are almost always caused by a weak spark or conditions of a lean fuel mixture. Ignoring these telltale symptoms can lead to a loss in horsepower and erratic performance, but in the long term can ultimately send your engine spiraling toward engine detonation and a costly rebuild if not addressed properly. With most factory ignition systems, we find the ignition energy to decline rapidly as dwell time falls below optimal levels. The drop in dwell time causes an inadequate time between sparks to fully recharge the coil and ignite the air/fuel mixture to fire that cylinder, generating a miss.
Plasma Direct is a factory replacement ignition coil system that uses a high-power amplifier built into the unit to increase secondary spark current by 100 percent-two times as much as OEM. The system produces four times more spark energy for the initial spark discharge than the average stock coils while also generating a highly effective multi-spark discharge of 10 sparks throughout the powerband. Compared to the factory coil that delivers a single-spark discharge, the Plasma Direct's multi-spark discharge and improved spark energy yields improved ignition and greater combustion efficiency, all of which is beneficial for those driving high-horsepower vehicles. Using an oscilloscope, we hooked up a factory coil pack to monitor its performance. The factory secondary ignition spark reached a maximum of 60mA before quickly leveling out. Whereas testing the same vehicle with an Okada Plasma coil pack revealed the secondary spark current reaching 140mA and showed a wave pattern present in the multi-spark oscillation that improves combustion and increases ignition spark. Okada Projects representative Akira Sato says the main importance with the Plasma Direct ignition is the change in current capacity and that voltage isn't important when looking to create an increase in energy spark. The oscilloscope shows the Okada Plasma Booster Direct goes from a range of 10 amps to -10 amps, which is twice that of the factory unit. The secondary current also reaches 100mA, which is twice that of the factory 50mA current, while also making an AC discharge not possible on the factory setup.
For all intensive testing purposes, we found a perfect candidate to run the new Okada Projects Plasma Direct ignition coil packs. A few phone calls in search of a Honda S2000 netted us with quite an interesting find. Gary Castillo of Design Craft Fabrication based in Lake Forest, Calif., offered a F20C powerplant engine transplanted into a Nissan S13 chassis that was dubbed the S13K. The vehicle and engine buildup was covered in a previous issue of Import Tuner magazine and was successfully completed a few months prior to the '08 drift season. The F20C powerplant was now turbocharged and generating 300-plus whp. The 2.0L mill is equipped with an AEM engine management system, 750cc injectors, Garrett GT2835 turbo, BC camshafts and a custom turbo kit built by Design Craft Fabrication. Strapped to the dyno, the turbocharged F20C, boosting at 14 psi, netted 325 hp and 330 lb-ft of torque while still using the factory coil packs.
Armed with a 10mm socket and an Allen wrench, the F20C plug cover was removed and set aside to expose the four 10mm bolts holding the factory coil packs in place. The bolts were easily removed and the plugs were unclipped before each pack was replaced with our new Okada Projects Plasma Direct system. Within eight minutes of swapping out the factory packs, we had the new Okada units in place. The S13 was spun on the dyno for its second run to see if the Plasma Direct was true to its claims. The dyno charts revealed an increase of 9-peak hp and an amazing 17 lb-ft of torque. At 4,350 rpm we saw an increase of 7 hp and 17 lb-ft of torque as our gains became more significant at a higher rpm, where the F20C transitions from low to high cam phase at 5,300 rpm. From 5,540 rpm to 6,900 rpm, we find the F20C reaping the benefits of the Plasma Direct system with a consistent gain of 7 hp and 5 lb-ft of torque. While horsepower gains were a definite plus in our books, we found the Okada Projects Plasma Direct to prove itself worthy, as the new coilover plug setup helped clean up our forced induced machine at a higher rpm where we were prone to stumbling previous to the installation.