[Bebbetufs]

Some important thoughts here. Personally I want to maximize on-track performance. I don't mind losing a bit of torque as long as there is an overall gain. I can see why most people would be dissapointed by a loss of torque.

I agree that the boxser engine has more torque but the usable area under the curve does not feel that much larger since the Clio revs higher. This is on track. In traffic the Renault requires more work than the boxer engine to access its potential, so you are definitely right there.

FWIW the "kick" when the cam timing changes feels about the same on both engines. Also, the Clio can be easily and very affordably remapped to remove the environmental flat spot the factory put in.The Clio revs to 7500 and feels very quick. Of course it has a close-ratio 6 speed box which makes it easy to stay in the power band.

You are right about the 4-2-1 headers. They are a work of art. Renault also has a racing header for this engine. In race trim it delivers around 250hp. This brings me back to the original thought that the collectors on a 4 cylinder are more effective at scavenging than on a 6 cylinder boxer. The pulses will arive closer together in time and ther will be no pause per cylce which, as far as I can tell, there is on the 6 cyl. boxer.