Re: Claims vs. Claims - getting them straight

[QSHIPQ@aol.com]

In a message dated 97-10-28 13:59:39 EST, you write:

<< > >From them I extrapolated only the basics to the claims in accepted
engine and
 > turbo theories, math and physics.  Maybe you can explain how 513CFM goes
thru
 > an MC motor.  Or how you control boost to 2.79PR with a 2.5 bar PT box
with a
 > stock spring?  Accepting the usual 1.5 factor for airflow, 342 hp? It
seems
 > to apply well to the audi motor cuz the RS2 is really close 460CFM/1.5 =
306,
 > so is the claim 342hp or something else?  
 
 Hmmm.  Let's apply some of that to the stock configuration.
 
> 1.43 PR, 162 hp.
 
 >1.5 for airflow gives 240 CFM, or 170 CFM for 1.0 bar.  Now Eric's
> 2.8 PR gives us 470 CFM - pretty close to that RS2 figure which would
> indicate to me that the performance ain't going to be much different
> to the RS2.
 
> BTW, what VE and RPM are you using to get the 513 CFM figure?
 >Given the stock numbers, I think you may want to reduce the VE.
 
 >And finally, to get 2.8 with a 2.5 pressure transducer... well,
> I guess the fuel pump cutoff must be disabled.  Living dangerously...
 
 Orin. >>
Ok, glad someone is cking me here.  I get
134ci * 5500 * .5 * .85/1728 = 184CFM @ 85% VE

So, 
1.43PR * 184 = 263CFM

263 CFM/1.5 (factor) = 175hp for a 162hp motor.

Ok, so let's back that up and correct VE

134 * 5500 * .5 * .80/1728 = 170CFM
170 * 1.43 = 243
243/1.5 = 162.6 (that's a keeper)

So, 85% appears high for a 10v, and about dead nuts for a 20v motor (assuming
we agree that the 1.5 is the actual, it really is an estimate)

Ok, now lets throw that back to the claims @ 80% VE (prolly better for a 10v
motor anyhow)

134 * 5500 * .5 * .80 = 170CFM
170 * 2.79 = 474.3

474.3/1.5(est.) = 316.2hp

Ok, I guess I could rephrase the question?  How is it that 316hp is claimed?

Ok, so either I have to take the correction to the 85% VE (which I will, and
will repost my original numbers) or the correction doesn't apply to the 10v
motors from audi.  I'll bite on the former, since the 20vt RS2 with a 85%
looks to be pretty accurate.
What this really does is make my original post that much more blatent in the
question part.  Assuming one was to choose a hybrid turbo that has a PR of
2.79 or an RS2 that has a PR of 2.50, which would give the higher DR?  Output
is the same, so how could a hybrid turbo "blow the RS2 into the weeds" when
the output is the same at a higher DR?  Even a more perplexing question in my
mind.

To give the S.O.c the benefit of the doubt, I will repost with the original
numbers corrected for 80% VE

Scott, RS2 wannabe (even more now)