What is the optimum shift point when drag racing? put aside engine mechanics and focus on a theoretical dyno graph in your mind. would it be to shift so when you hit next gear your at the peak of your torque curve, or to shift over the broadest curve of your horsepower? (ie 300hp @ 5000rpm, 350 rpm @ 5500rpm, 300hp @ 6000rpm) would u shift at 6k? or 5.5K since that is peak hp?

what is your thoughts, and/or knowledge, or guesses. any eveidence to back it up?

 

You shift for most HP under the curve for highest speed.
That means your HP at recovery RPM would be equal to your HP at the shift.
If your recovery RPM would really be 5000 RPM after the shift, then your best shift point would be 6000 RPM in your example.

This method will give you the highest average speed (MPH) and highest trap speed, but not neccessarily the lowest E.T.

It's not neccessary to recover at your torque peak, but if you must shift too early to get highest HP under the curve, then you'll want as much torque as possible at recovery RPM.


E.T. is more tricky than speed.
Recovering at your HP peak could actually net you the quickest E.T. as long as the HP curve doesn't fall off too fast.
If HP falls off too fast after peak then you may find your best E.T. by short-shifting early so that your shift point is closer to the HP peak.

It all depends on the shape of the power curve and also how the car is geared.

 

I typically shift when I am down to 90% of peak HP, torque is falling drastically, or at Redline, whichever is first. My 305 peaks at 5,500 rpm, I have the transmission setup to shift at about 5,800 rpm.

A chassis dyno run can tell you pretty close, where to shift.

 

thanks, once my motor is up and running, ill dyno it and post it up.