Tuner or no?
05-11-2019, 07:44 AM
#21
Member
Changing the shift points has no effect on engine RPM per given vehicle velocity. The only thing that effects that are gears and tires.
Put it this way: if right now you turn 1800 RPM at 65 mph, taller tires means you’ll be turning, say 1400 RPM no matter when the transmission shifts. Your speedometer and odometer are off by the same percentage. Lower gears compensate by bringing the engine back up to its proper 1800 RPM at 65. (I made up the above numbers to illustrate the point). A later shift point just means the engine and vehicle will be going faster when it shifts, but once you get in gear, a given engine speed is moving the vehicle the same it would have before adjusting the shift points. Adjusting shift points simply gets the engine up into its power band before upshifting so it doesn’t fall on its face after the upshift.
Put it this way: if right now you turn 1800 RPM at 65 mph, taller tires means you’ll be turning, say 1400 RPM no matter when the transmission shifts. Your speedometer and odometer are off by the same percentage. Lower gears compensate by bringing the engine back up to its proper 1800 RPM at 65. (I made up the above numbers to illustrate the point). A later shift point just means the engine and vehicle will be going faster when it shifts, but once you get in gear, a given engine speed is moving the vehicle the same it would have before adjusting the shift points. Adjusting shift points simply gets the engine up into its power band before upshifting so it doesn’t fall on its face after the upshift.
