If you are talking about driving in a straight line, you are probably right. (If you can actually get all of that power down without lighting up the tyres!).

On a track though, even the "slowest" one of these Caterham's will eat it for breakfast http://www.caterhamcars.com.au/pricing.php

Going fast in a straight line is one thing, but hauling up that HSV's ~2 tonne weight and trying to make it go round corners is where it will all slow down.

There is a substitute for displacement, it's lightness and handling! ;)

As Colin Chapman (who designed what is now that Caterham of course) famously said, "Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere". It's a matter of which philosophy works for you - some want lots of horsepower, noise, grunt and all that, others prefer to finesse a machine to its limits. Horse(power)s for courses!