Chargecoolers

[Neil Swanson <75377.3445@compuserve.com>]

Air vs Water,

One of the grips about S4/6s is the IC location and the great legths of
tubing.  But it needs to be in the air stream and space is limited.  The
long tubes may hurt response and may add increased work for the turbo for
you to see that big 2.0 on the gauge.

One of the great features of the air-water ICs is that the chargecooler
itself doesn't need to be in the direct airstream, just it's water rad
does.  The chargecooler can and should be mounted very close to the turbo
and inlet.  Less work for the turbo as it isn't overcoming 6' of IC tubing.



But to put an air-water way the hell over where the OE IC was leaves you
with all that long tubing.  This may sort of remove one of it's advantages.
 Or I should say you aren't taking advantage of one of it's great main
features.

So try if at all possible to put the charecooler as close as possible to
the inlet and turbo.  It CAN be anywhere.  

So this is all theory.  It may be that with a really good water heat
exchanger that the chargecooler may work really well in the OE place. Even
with all that tubing.   Only someone who has done it and tested temps will
know.

One thing I think most all OE air-water systems fall short is in the volume
of water they carry for the system.  Up to a point the more the better.
More water will take longer to heat.  And it may never get as hot as too
little water.  I suppose if you got too much water too hot then it would
take too long to get cool again. 

Want to stretch this point a HUGE amount.    There was a '66 Mustang at
Bonneville this year.  The owner told me charge temps were 30F!!!! at the
start and 100F!!! five WFO miles later.  That is what 100lbs of ice do for
you.  Damn brick went 236mph too.


In Tenn one of the Merkur bros did his own air-water IC.  Spearco core and
Pace of UK pump and rad.  The rest was his own work and very well done. 
100% ZERO lag.  He has only 14"s of IC tubing not including the IC itself. 
I have 7ft! in my front mount IC.   The best air-air system a friend in NJ
makes is 4.5ft.

  This air-water system carries a little over one gallon of coolant.  He
reports quick recovery to near ambient inlet temps after a thrash.  But as
he admits, wait till a Tenn summer.

Neil