Project FR-S: Getting Torque Everywhere with an Innovate Motorsports Supercharger
Our FR-S is a difficult car to deal with in the engine department. The ECU with a lot of command authority has been driving us nuts. We have put several thousand miles on our FR-S over the last few months and it seemed like the car was once again dialing out a lot of our power over time.
If you can remember from previous installments we had done a accumulation of several hundred dyno pulls trying to get repeatable dyno results, removing and re-installing parts many times. Being curious we decided to dyno our car again. To our dismay the car had returned to nearly stock power levels again.
We were thinking that the erratic power readings might have been due to the tune we had done on the car that perhaps wasn't very suitable to our 91 octane gas. To test this thinking we flashed the ECU back to stock and still experienced wildly erratic power on the dyno.
What we ended up doing with the help of Innovate Motorsports was to reflash our ECU with a stock program with a less aggressive ignition timing multiplier constant. This gave us consistent readings but we were disappointed to find that our cumulative mods only made 5-6 more whp than stock. At least the runs were stable.
Our theory is that the FA20 engine with its high 12.5:1 compression is not really happy with California's crappy 91 octane pee water. Possibly a less aggressive tune might actually make more power. It works for cars like the EVO and the STI!
Being confounded with our efforts to gain power, we decided to take a big step by going forced induction. Innovate Motorsports has just come out with a twin screw positive displacement supercharger kit for the FR-S and BR-Z in addition to a tune that is stable with California fuel.
We have liked the torque everywhere, wide powerband, bigger engine feel that a postive displacment blower gave on some of our other projects and our FR-S surely needs more power everywhere!