[s-cars] article on horsepower conversion, rwhp to flywheel

[Brian Powell]

> By contrast the VW 5 valve per cylinder engine has plenty of inlet
> valve
> area from its 3 inlet valves per cylinder but space constraints mean
> the
> lifters are only 24mm diameter. This limits the design of the cam
> profile so
> badly that the power potential of the engine is reduced below that of
> the
> much simpler 4 valve per cylinder design. In effect, this engine ended
> up as
> nothing more than a very complex and expensive marketing exercise.
> "... from

Well, they are absolutely wrong that it is an "expensive marketing
exercise."  From a tuning standpoint, I agree.  However, from an
emissions and efficiency standpoint, Audi is positioned far ahead of
the 4-valves as stricter governmental controls around the world kick in.

Sure, we'd all love more valve displacement, piston displacement, etc.;
however, the manufacturer has to worry about little things like the law.

There has even been talk in CA of REQUIRING all cars to have a minimum
of 5-valves for emissions control.

Cheers,
Brian