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Old 01-13-2013, 06:33 PM   #149
gmookher
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Join Date: Aug 2012
Drives: VortechSC,BorlaEL,Perrin,GCRace
Location: HighHeatHighAltitudeAZ,USA
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For those of you who have never done FI at altitude, the math is simple, if @skatery1989 lives at 5000 feet, on a supercharger the loss will be about 5%HP on low side, even more as temps increase. I may be wrong here on the exact percentage, it may be 4% or 6% but lets just say there abouts per 1000

why? cause fuel is metered according to MAP, not altitude or boost

VE is never ideal % at altitude, volumetric efficiency is a ratio (or percentage) of what quantity of fuel and air actually enters the cylinder during induction to the actual capacity of the cylinder under static conditions, ie ideal sea level and ideal temps. motors rarely see ideal. 3% is ideal loss. its more in real life.

I think its closer Approx. .5 psi boost per 1000' of atmospheric pressure is lost due to elevation. Boost plus atmospheric pressure is called absolute pressure. 14.7 psi at sea level +10 psi boost = 24.7 absolute psi.

if his atmos pressure at 5000 feet is 12.2psi, his absolute will be 22.2psi

if he is loosing 2.5psi due to altitude at 5000 feet, his MAP is lower, unless he spins his SC faster he cant compensate to make more power; but he can end up with too much MAP at sea level if Perrin and Vortech arent careful in dialin in and system setup.

At higher altitudes, air is less dense, and thus boost is decreased.
the goal should not be to have him make the same HP at 5000 feet as sea level, physics will make you have a bad day if you play that game

He's gotta be putting down over 220-225whp at sea level, as my guess, conservatively on 91 oct
on 92 -93 at sea level I suspect 240whp

Quote:
Originally Posted by 2forme View Post
Absolutely. Toss on a smaller pulley and you can have low-mid range torque too..
Yes, yes indeed, but its not my place to tell you this, no one would believe me anyways.. just lets wait for the dyno curve of THAT setup..at sea level, an its gonna knock your socks off,

-but wait theres more-

if the pulley gets you hot and bothered, the stuff I hear about thats being tested will surely make you shoot your load. This kit just keeps getting better.
and better
and better

makes me feel like I have donated my car to "science, and explorations of new frontiers for humankind"

http://www.wallaceracing.com/braking-hp.php

Last edited by gmookher; 01-13-2013 at 07:02 PM.
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