Re: Correction for: .5*Dave,Dave et.al.

[QSHIPQ@aol.com]

In a message dated 97-10-28 15:50:44 EST, you write:

<< > *  S.O.c claims and audi facts:
 > *  26psi in 2nd thru 5th
 > *  2.5 bar PT
 > *  16+psi in 1st gear
 > *  .5 PD accross modded IC
 > *  Audi --> RS2 gets 310hp @ 460CFM
 > *  1325 EGT
 > *  Audi --> MC motor = 134ci
 >
 > The homework would be
 > A) How does a 134ci motor flow 513CFM in 10v trim?  Can it?
 > B)  Why such a large PR?  I thought Density Ratio was more the goal?
 >  
Long formulas deleted, summation:

 Fe = Fa*Rm = 183.7*2.57 = 473.2 cfm

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Dave, 
On further review of your homework, I think you did it forward, when you
should have gone backwards, which you have to do in this case.  Remember the
claim is 26psi, in this case, is measured AT the intake manifold, you are
assuming that to be before the IC in your long math as presented.  That
means, the given in your equations is:

Fe = Fa*Rm = 183.7*2.79 = 512.5  (assuming 85% VE that is)

So your long math is the same, and it should be with the 80% VE correction.
 All this really indicates is that the effective PD from PR vs DR makes this
an even higher number upstream.  Make sense? Don't forget, a given is also
.5PD across the IC.  

Your math backwards might also give a good indication of what the mods HAVE
to be.  Either VE or IC eff HAS to be really high.  Maybe too much so.
 Thanks again for the plug ins.

HTH

Scott Justusson, RS2 wannabe
'87 5ktqwRS2
'87 5ktq
'86 5ktqw
'84 Urq