Wobbly, a couple of musings on your power curve---
In “observing” your power curve in reply 287 the “flat-topped” horsepower curve just didn’t seem consistent with the torque curve. After cranking a few numbers, it appears that the horsepower data points at 7400 and 7800 rpm are plotted one unit too high. While this is not a big deal, correcting the locations more vividly shows that you were running well beyond the approximately 6800 rpm current power peak.
Also, as you embark on more inlet and exhaust tuning, it may be useful to recall that what may be good at 60 degrees in Oregon may not be quite optimum at 95 degree Bonneville. This would amount to about a 3.5% increase in acoustic celerity--again, not a big deal, but an indication of which way to round off dimensions, or a reason to include some “shimming” capability in the inlet tract.
Getting the inlet, exhaust, and valve timing all coordinated will probably keep you well occupied over the winter.
Re: Your “driving force” performance evaluation process (reply 289):
First, there is a much easier way to calculate the tractive effort, or “driving force.” Force times velocity equals power. More particularly, Force (lb) x Velocity (mph) / 375 = Horsepower (hp) and conversely, Force (lb) = 375*Hp/mph. (This is just a linear version of a relationship you are already familiar with--Hp = torque (rotational force) x rpm (rotational velocity)).
Example: 70 horsepower expended at 125 mph produces 375*70/125 = 210 lbs of “driving force”.
One could also include an efficiency factor to account for driveline losses.
Second, why do you care what the torque or driving force is, except to get an idea of the aerodynamic drag?
All the torque in the world won’t pull the skin off a grape. To do work (go 130 mph at Bonneville) one must apply POWER. Likewise, to accelerate you need to apply power. Don’t worry about how broad the torque curve is or is not, worry about the power curve. Manipulate the power curve itself by tuning changes, and its application by gearing arrangements.
Of course, none of this is meant to criticize you or your methods, it just illustrates a different and perhaps simpler perspective that may be useful.