I went to a Dyno day today and was pleasantly surprised.
a bit of preparatory explanation here.
My boost controller spikes in boost and then settles.
The first run peaked at 13 psi, settled to 11psi and produced 142.6 kw at the wheels, which translates to 191.2 horsepower at the rear wheels.
So I decided to ramp it up a bit and went a half turn on the controller.....we'll get back to this.
A 1/4 turn produced the sheet you see below
peak boost is 15.9psi and settles to around 13psi
peak power is around 7000rpm to 7200 rpm and at these revs it is only boosting around 12-12.1psi.
the power starts to level off at 5500rpm.
This was a bit of a surprise because I thought it would be around 4000-4500rpm.
Between 4500rpm and 5500rpm the power goes from 75kw (100hp) to 150kw (201hp)
So it basically doubles the power in 1000rpm
That is why it hits 4500 and goes LUNGE!!!
Back to the half turn story.
If you follow the trajectory of the above power line, imagine it continuing upwards.....
It cracked 170kw (228hp) at 5750rpm and 20psi when the operator called a halt with a bit of detonation.
Interestingly, the air/fuel ratios were if anything on the rich side, ramping from 14:1 down to high 11:1 at full boost. Even at 20 psi.
That tells me that the detonation is caused by timing, which would be the Japanese chip in the ECU.
After a small talk with the dyno guys, it will run all day every day as it is now.
But if I were to perhaps embiggen the exhaust (it is a 2 and a half inch press bent at the moment) and tune some of the timing out we could substantially embiggen the power curve.
Oh, and get a boost controller that doesn't spike
Finally, a little (creative)accounting.
Driveline losses are calculated at 30%
So 152.8kw divided by 70% = 218.28kw at the crankshaft.
Divide that figure by .7457 (kilowatt to horsepower conversion) and that gives me 292.71 horsepower.
That's as close as dammit to 300 horsepower at the crankshaft!