We had a couple of issues on the rollers. Firstly, my alternator is not man enough to run all of the electrical crap on my car, so the voltage dropped down in to the 11s. Not good for a decent spark. Secondly, my CNC throttle pedal snapped on the dyno whilst at wide open throttle at full rpm on a power run. As you can imagine, pandemonium ensued, but luckily I had fitted a battery cut off pull switch on the right rear corner and I was able to kill the power before the motor blew up! Anyway, we carried on with a makeshift hand operated throttle cable. That was a little tricky, but it worked.
We made 14 power runs in total. First runs were to map fuel at 13 psi of boost. All good, over 300 horsepower. We then started to increase the boost by increments of 2 psi and corresponding fuel increase. Each time the power went up by around 20 hp. At 18 psi the motor put out 414.9 bhp. After 18 psi, however, it became apparent that the ignition system was not up to the task of dealing with the power. Maybe it was the low voltage, not sure. Anyhow, we tried all sorts: changing plugs and closing plug gaps, but the ignition kept misfiring above 18 psi of boost. Back it down to 18 psi and all was good again.
We did have one run at 22 psi that did not have spark failure. Bhp went up to 457, but as we couldn't replicate this with another run due to misfires, we can't really say if the power reading was on the money or not. It looks like we are going to step up to a CDI ignition system shortly, so the plan of running 30 psi of boost may become a reality. I reckon that might be a go for next year though, as 400 bhp is still going to make me soil my boxer shorts ;D. I need to learn how to drive the car first...
