paradisenb

Anyone have the Torque/Horsepower Graph for a 2000 Boxster S?

Post or PM it.

TIA

94twin

paradisenb

94twin
Thanks a lot.
The graph matches my foot really close. I've been shifting at 62-64K for smoothness but, based on the graph I can back off to 6k. Figuring approximate drop off of 2k RPM between gears I'll end up right near the sweet spot.

Mike Murphy

Nope, if you back it off to 6000, you'll lose power. You're trying to achieve the greatest area under the curve, so keeping the revs between 5200-7200 would yield the most power. If you want to shift at 6000 to save a little reliability, that makes sense. I also shift at 6000 around town, but on the track, I would pull all the way up to redline, every time.

986Jim

Murphyslaw1978 is absolutly right. It has nothing to do with being in the area that has the most power while your accelerating. At 5000rpm even if your making more HP the car accelerates slower than it does at 7000rpm. The higher the RPM the easier the engine can accelerate and the less hp it takes to go faster.

If your power peaks at 6000 you still rev to the highest rpm possible no matter what. If you wanna see what it does, test it on a g-tech or at the track.

blue2000s

Your shift points totally depend on your driving goals at the time. If you're trying to keep up fuel economy, get into teh highest gear as soon as possible without lugging the engine.

If you're looking for the best acceleration, on THIS car, redline is the best choice for the shift point under wide open throttle. Why? Quite simply, you want to make the most torque at the wheels at any given road speed. The combination of gearing and engine torque curve for this car show that for any given road speed your best torque at the road is produced in the lowest possible gear (as long as the engine is under it's redline).

This IS NOT TRUE FOR ALL CARS and has to be evaluated based on the car's torque curve and gearing, as I mentioned.

blue2000s

Not true. Inertial energy goes with the square of speed, it takes much more energy to go from 6000-7000 rpm than from 1000-2000 rpm. That's not accounting for the increase in friction with engine speed. Although redline is the correct place to shift for best acceleration on this car, your reasons are incorrect.