[Anaxilus]

A positive displacement supercharger should be much easier to calculate than any turbo rig. The prior posts make good points but I think some of you might be over thinking it in this case. I'd say around 260hp on E85 is more than logical.

The FA20 already makes 100hp/liter, that means it flows quite well. In a perfect world, w/ a PD charger you can simply take a percentage of 1bar (14.7 psi) that the stock motor operates at under NA and calculate the multiplier as a percentage of 1bar that you are adding. Assuming lack of intake restriction (Remember, the Innovate system comes w/ it's own tuned manifold).

So let's say 7.5 psi is roughly 1/2bar, this translates to adding half your NA value, thus 200hp (crank) + 100hp= 300hp total (crank). However, if the Sprintex graph is right, then it operates at 90% volumetric efficiency, so more like roughly 100 x .90= 90hp (ignoring intake charge temps for the sake of simplicity). Thus total 290hp (crank). So now let's minus roughly 10% for parasitic losses = 260hp (crank). Minus another 15% for drivetrain losses and you are at 210-220hp (wheels).

So take that 210-220 and add E85 to the equation and add maybe another 10% back, you get 230-240hp. So where's the 20hp discrepancy w/ robispec's numbers? Ah, we didn't calculate his increase in volumetric efficiency on both sides of the air pump due to improved intake and exhaust, better tuning/mapping, changed pulley/boost, reductions in frictional and rotational mass losses, all of which convert to more power. Thus finding another 20hp doesn't seem unlikely, nor would calling the dyno potentially generous be unreasonable. Either way, the numbers all look roughly in the logical ballpark to me.

This is why I consider the rated HP rating of a blower and it's max BAR to be something of a red-herring. If I know it's volumetric efficiency, and the engine's VE, the math is relatively straight forward. To me, this does not look like unicorn numbers at all.

If this were a turbo, the math is more complicated due to variable VE and intake charge temps. If the efficiency of the motor was lower, then yes I would see unicorns too. Imagine how well a PD charger would do on an S2000 at 120hp/liter. Common S2000 numbers seem to indicate an rough average of 330hp at the wheels under similar conditions. Again, this makes sense if you increase the FA20's efficiency by 20%. Could this Innovate PD charger get you there? That would be more of a concern for the S2000.

These numbers aren't 100% accurate at all, but are relatively straight forward and in the ballpark of reality. So nobody should be worried about making only 180hp or hope for 600hp at the wheels w/ this kit.