[s-cars] Ceramic coating - EM / Turbo

[Djdawson2 at aol.com]

In a message dated 5/13/2005 4:32:18 PM Mountain Standard Time,  
rletsinger at gmail.com writes:

But the  stock or RS2 EMs place the compressor housing
right next to the #1 and #2  exhaust runners.  The temp of that
manifold is way higher than the air  in the compressor housing.
Yep, true... but a simple barrier could be used.

Which is more like 150 to 180 degrees in my engine.  At 350 you'd have  to
have one heluvan intercooler to get that back down to  ambient.



350F compressor outlet temps are just a figure that I grabbed from  published 
folks (like C Bell) as representative of typical.
 
Also, consider this...  If you take air at 70 degrees F, and you take  it 
from atmospheric (1 bar), and add 2 bars of boost... and assuming that you're  
only compressing it to 50% of its original volume (this is a safe assumption),  
it follows that your compressor outlet temp will be over 340F.  This  doesn't 
even take into account any mechanical heat transfer (you know,  100,000rpm 
compressor wheel activity and such).  This is application  of the Ideal Gas Law.  
In other words... If you're really running 20+  psi of boost, and your 
compressor outlet temps are 150-180F, you are currently  defying the laws of 
physics... so I will either applaud you, or question your  gauge... most likely that 
latter.
 
As far as an intercooler being able to get compressor discharge temps back  
to ambient... well that's a whole other debate.  Do the math and see what  kind 
of IC efficiency it takes to perform that task...  realizing that air  to air 
ICs are typically only capable of returning about 85% in ideal  conditions.  
When I do that math, it makes me question the validity of the  figures 
returned by the popular Davtron.  But like I said... that's another  debate in and of 
itself.
Take care,
Dave