How can I use the torque & HP vs rpm curves of a racing car advantageously?

Question

In particular, I want to know under what circumstances I should be driving the engine at max torque point or max power point.

Answer 1

You are generally aiming to have the gear ratios such that when you upshift, you wind up at, or near the torque peak of the engine in the next gear. Though this is not a hard and fast rule, as it may be more important to get the gear ratios set up to 1) take the most advantage of any long straights, 2) avoid short shifts at awkward points on the track.

If you don't have the resources to redo the gearing and final drive for every track you visit, then you simply have to work out the best you can; stock gears will normally max out just after the power peak, and should up shift to near the torque peak. After that, it's just common sense to sometimes decide to short shift before some corners, or to not upshift just before hitting a braking zone.

Answer 2

The engine builder and a great dyno. machine operator can do wonders for you. Generally speaking, road race engines are built for more torque at lower rpm's and a generous long torque curve. The camshaft has closer lobe centers with quick opening and closing ramps. Also these cams are usually advanced 1 or 2 degrees. The intake ports should be kept on the small side and be ported using a programed CNC machine. Nowadays intake ports are not smooth slick and shinny. The ports are machined with rough ridges around the circumference of the ports down to the valves. This practice helps to mix incoming fuel and air so puddles of raw fuel won't tend to form. High constant rpm engines have a quick High lift and more degrees of open position of the valves followed buy a slightly longer valve closing rate. This type of camshaft is usually retarded somewhat. The torque curve is much shorter but peak horsepower is obtained at the highest RPM that the engine safely can be run at.

Answer 3

Im not an engineer, but I personally would think torque is most important when driving out of a corner, and horsepower is most seen 2/3 down a straightaway.