"David Hawkins" <otgrouch@twosrus.com> wrote:
> The single most common modification to a turbocharged car is to up the
> boost. Instant EM car.....is it fair? You bet.
Hell no, it's not fair - but that is the rule.
> Boost mods are almost impossible to police, and the gains from each one will
> be different and would make a classing nightmare.
This is a myth, and a popular one at that. All forced induction cars have a
natural limit to the amount of power that can be made with the stock
turbo/blower. The things only flow so much air, and no matter how much wizardry
and voodoo you do with boost control devices, _as long as the impellers and
housings themselves are not modified_, there is an upper limit to the amount of
power a given motor can make.
Take our supercharged friend here. If he spent a day on the dyno, swapping in
progressively smaller pulleys (to drive the blower faster) and adjusting the
fuel delivery to match, he'd find that there would be a pulley size where if he
went any smaller, he'd lose power. Either the airflow limit of the blower has
been reached, or it's efficiancy limit has been reached. (ALL compressors,
because of immutable laws of physics, impart heat into the air they compress. At
some point, increasing pressure actually decreases the amount of air molecules
being forced into the engine, as the hotter air temperature with the increased
compression results in a lower density.
This gets particularly nasty with supercharged cars, as they have a direct link
between engine RPM and compressor RPM. If the car is set up so that compressor
efficiancy peaks at any point below max engine RPM, then revving the engine past
that point will result in lost power.)
As long as that theoretical max power value is within the bounds of the rest of
the cars in his class (adjusted for weight, suspension type, maximum tire size
etc. - power is not king in this sport) then nobody is hurt. In fact, as
turbo/blower cars tend to be conservatively classed in the first place, odds are
that the mod is an equalizing factor. And if not - reclass the car.
There's no need to punish people like this by forcing them into Mod. Allowing
open boost controls - but requiring unmodified boost producers - in SP works out
the best for everyone.
- It's easier on impound, because the only part of the system that is
regulated is the physical bit that comprises the turbo or blower. If the serial
numbers/model numbers are correct, and it hasn't been machined or modified, then
it's legal - verifying legality is now much like checking a cylinder head. You
don't need to be a rocket scientist to see if a turbo has been ported or
clipped.
- It's easier on non-turbo fellow competitors, as there's no longer any need
to have to understand that snakes nest of hoses and vacuum lines in the other
guy's car, or to worry that there's a modification hidden in there that you and
the impound guy don't understand and so can't possibly find, or that there's
some sneaky and undetectable computer modification, or whatever.
- It's easier on newcomers to the sport - "Hey, nice boost controller!.
You're over there, in E Mod, next to that guy bolting down that carbon fibre
Fiero body over his Formula Atlantic chassis, right next to that twin-turbo
5l-Ford V8 powered Mini. Good luck on your first day!"
- It's easier on "serious" turbo competitors, as they get a little more power
in their (usually) conservatively classed car, and they get the ability to set a
hard limit on they amount of boost they want to run.
I still can't find _anyone_ who gets hurt by allowing boost controllers in SP.
DG
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