Best shift point: Torque Versus Horsepower in a GT350

[gregsdart]

Its pretty simple really. Keep the motor in the highest average hp you can for the gears you have, and the trans ratios will take care of torque multiplication to produce the best acceleration curve.
My drag car has a peak torque of 5100 rpm, max hp at 6900. But what has proven to be fastest is a stall of 6,000 rpm(actual) and shift points of 7350 rpm, with 7400 rom at the finish line. Even though the loose converter isn't as efficient as a much tighter unit, the motor is making more power up there than the loose converter loses to slippage, so overall average power delivered is higher.
If you want to really feel torque, then load the crap out of the motor with boost from a twin screw blower. About 12 psi will double the torque at low speeds, making my blown 4.6 gt more fun at low rpms than a new gt!
But you still have to spin it up to get the best times. 6700 in the case of my 4.6 2006 gt.

Sponsored

 

[Grintch]

My favorite way to calculate the optimum shift point: Get a dyno curve for your car or a similar car (you can almost surely find a stock or close to stock curve with a quick Google search). Now multiply the torque times the gear ratio for each rpm step. As soon as the combined torque is higher in the higher gear, that's when you want to shift. It also helps to have a gear chart so you know the rpm drop between gears. No need to calculate the area under the curve or anything fancy. Just pick the bigger number.

 

[11GT50]

Does the heads up shift light "know" whats best for speed, or is it thinking MPG, etc as well?

It's based on the RPM setting you choose in TrackApps.

And I assume when the car is put in loud mode, it must by-pass some baffles, therefore more power?

It opens a butterfly valve in the tailpipes. No additional power.

 

[NoVaGT]

......My wife and kid will also drive this car on occasion......

 

[key01]

Read the manual on the shift light configuration and settings. It is highly customizable to your preference

 

[proeagles]

Read the manual on the shift light. You can set it for different conditions and different RPM. I have my set in track mode where the lights come together and shift when they do. I have mine set at 7K RPM for the street. This engine pulls like a freight train to redline pretty much and I would shift it somewhere around 7900 to 8000 if drag racing which the car is clearly not designed to do.

 

[tex929rr]

Just based on my sport bike experiences, if you want max performance you have to keep the revs up. Those little engines that spin to 14000+ rpm’s have to be kept boiling, as their torque and HP both plummet as revs drop. The Voodoo is only slightly less extreme than those motors.

 

[gregsdart]

there is another factor that can affect best shift points, engine inertia recaptured going into the next gear. Its effect is very dependant on a number of things. Gear ratio change, over rev during the shift, available traction, clutch efficiency. I have no idea how much it will affect a GT 350 with stock gears, but have seen it have a big effect on drag cars. A friends drag car needed about 400 to 600 less rpm on the 1/2 shift versus the 3/4 shift. 3400 lb car, 440 cube bigblock chev spinning 9800 on the 3/4 shift. Try and shift it the same rpm and it would run 9.50s instead of 9.teens

Sponsored