[DeTomaso] An engine-bay shot from Japan

[Daniel C Jones]

> How can it not be accurate for torque if it estimates power correctly?
> Power is just torque x rpm, so unless the rpm is wrong in the other
> direction, everything should fall into place.

The program has been accurate in predicting peak HP but optimistic in
predicting the peak torque, which occurs at a lower RPM.  Another way
to say this is it is more accurate at higher RPM prediction and less at
lower RPM.  There are several potential reasons for this.  The program
assumes perfect atomization of the fuel which does not occur at lower
RPM, as well as a perfectly stable air-fuel ratio.  The mode I run the
predictions in computes optimal timing at each RPM, though there is a
mode to enter your actual spark curve and air-fuel ratios to further
refine the simulation.  Finally, the induction tuning assumed by the
program is probably stronger than the actual.  In the simulation, the
average intake runner length is used, along with an ideal taper angle
from the plenum entry area to the minimum area (just under the valve
seat), is assumed.  In reality, the 351C has short and long runners
which spreads out the torque and lowers the peak and the Blue Thunder
intake manifold and CHI 4V heads do not taper at a constant angle.

More later.  I have to go shoot some fricken' Laser beams in the desert.

Dan Jones