Quote Originally Posted by Mirek View Post
This is a bit difficult because all scenarios are somewhat theoretical both mine and yours.

You are right that the important thing is torque on the wheels but that is why I give the example in speaking about power curve. Because the torque on the wheels x wheel speed is the same thing as the engine power minus mechanical losses, i.e. speaking about power curve simplifies things (when talking torque you anyway get from one power curve to another power curve but in a more complicated way).

You are also right that normally the teams will try to limit what they loose in the power band by using different gearing but they need a ballanced peformance, they need also certain top speed on straights, traction etc. In other words where one team can use shorter gearing to their advantage the other can do as well and keep their advantage (or put the advantage on top speed if needed).

Why it matters more on twisty stages (in my interpretation based also on long time observation) is because no matter how much time you push the throttle you always need to deliver biggest possible energy on the wheels in that period of time, i.e. largest possible graph area under the power curve. In twisty events it is physically impossible to keep the engine RPM tightly around the peak power and therefore car with flatter curve will always have advantage because between two gearshifting it always delivers more energy to the wheels.

The second reason why it matters more in lower speeds is traction because car with flatter curve has smoother delivery of the wheel torque (less raise or drop of torque).

IMHO this was very well illustrated in times when S2000 were the second category. They had very low torque compared to the turbo cars but reasonable power. They were able to keep within 1 s/km on very fast events (Finland for example) but the difference was around double on twistier mountain events (Acropolis for example) and even worse in muddy events (up to tripple sometimes).

You are right that normally the team with stronger engine may use advantage of the higher top speed but they also may opt for other options, for example higher downforce, hence why we can not know whose engine is more powerful just by looking on the onboards. We don't know how they ballanced the drag/downforce/power/torque/gearing/traction and how successful they were in their preparations.
There is no scenario where an engine with a flatter curve will not be better. But I still believe that with more optimized gearing in the more technical sections the driver can make a big part of the deficit up with his driving, setup, accurate gear changes etc. But if it is a fast rally where the drivers will be in top gear nearing the limiter for long amounts of time then there is absolutely nothing the driver can do.

For your S2000 point i think the best season to look at would be 2012 with Ogier in the Škoda Fabia. I had a quick look at EWRC-Results. His average speed was 1,9 lower in Greece and 1.73 in Finland than the leader. Not a massive difference. And the loss is not only from the lack of engine power for the S2000. As a counterpoint I would point to the ERC or national level in the S2000 or early R5 era where the N group cars could hang on with the much more nimble opponents on fast rallies like Estonia thanks to their superior top speed.