RE: Fuel prices / efficiency

[Mika.Helander@softbit.fi]

This is interesting; as I read from Wizard books the parasitic drag caused
by Roots supercharger is fairly high, and Whipple ones are too expensive (as
most centrifugal ones) so I skipped those chargers. Now I'm thinking of (or
more likely twin-) Turbo -- thanks Bruce to turn my feets back to ground ;->

Here in Finland we have lot of Saab's and Volvo's equipped with both
high-pressure and low-pressure Turbo's and the engine size is about 2-2.6L
and power rating is ~150HP so my current plan is to "grap" two nordic turbos
(both with computer-controlled waste gate) to my 350ci. The research
continues...

BTW, the fuel costs about 6.49fim/l here (95E unleaded) and 5,945730eur=1fim
and 1eur=0,989800usd so one gallon costs about 4.1usd !!! This explains my
interest in stock 350 van engine improvement interests to get much better
overall efficiency of the engine and gain some more power in high when doing
that.
One way to improve efficiency is to increase compression ratio and to go to
98E (our highest octane nonleaded fuel). According to Wizard increasing
compression might increase engine efficiency like 15% and it decreases fuel
consumption about same amount. This means that if 98E costs about 0.2fim/l
more it's all savings... But, to make power with Turbo(s) the compression is
normally decreased from stock ie. to hone the engine and put forged/extruded
pistons. And, of course the cam is matched to Turbo(s). Any comments?

-Mika

> I have had a street type (1" tube size) bypass on a fairly 
> low boost application
> (10-11psi), and it solved a lot of driveability problems I 
> had with the car.
> Honestly, the s/c drag on the motor is vastly overrated, 
> especially for centrifugal
> blowers that measure 15lb of boost or less.  I ran the car 
> with the belt attached to
> the blower, and the belt off, and mileage wise it didn't seem 
> to make any significant
> difference.  This was on a car that registered approx. 480hp 
> at the rear wheels, and
> still managed around 22-23mpg on the highway.
> 
>  Caveat:  some of the older blower designs, like the paxton 
> ball drive, take up a lot
> of power to overcome the ball friction.  The blower I used 
> was a powerdyne blower,
> which has dry ceramic bearings.  If you spin it by hand, it 
> feels like it has almost
> no friction whatsoever.  YMMV.
> 
> Daniel
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