Re: Still more hot air

[bearbvd@domain.elided (Greg Hermann)]

>Graham comes back to the question of how great is the power increase
>attributable to cool air induction? The difference in power between a
>Giulietta and a Giulietta Veloce was 10 hp, 12.5%, which is attributable to a
>combination of the cold ducted air, two Webers in place of the single Solex,
>7% higher compression (9.1 vs 8.5), 5% greater valve lift and about 5% longer
>duration. I would think that the Webers, the camshafts, and the compression
>ratio would get the lion's share of the credit.

John--

Let us not lose sight of the fact that the factory HP ratings upon which
you have based your comment were based on either the DIN or SAE standards
of the day (you do not specifiy which ratings you are talking about, and
whether you are talking about "net" or "gross" HP ratings--but those points
are all really moot in this discussion.

In fact _ALL _of the difference in the factory ratings is due to the cam,
carb, compression, & exhaust differences , normale vs. veloce. This is true
because _ALL_ of the HP ratings of which you could be speaking are based on
a testing standard (this is true of any of the usual DIN or SAE HP testing
standards) which _includes_ a correction to a standardized inlet air
density and temperature!

Thus, while a cold air intake has _no_effect_whatsoever_ on a factory HP
rating, it has a _distinct_ effect on functional HP in the real world!

Regards, Greg
>
>John H.

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