FW: failure notice

[Michael Pederson]

-----Original Message-----
From: Michael Pederson [mailto:mlped at dnvr.uswest.net]
Sent: Saturday, February 10, 2001 6:02 PM


Delta Force - Intercoolers that is - Any Data?
Any speculations on efficiency?

Ok, The Don confessed this afternoon that there were "... at least 20 people
in on it...."

"It" being the 1st Davtron / Andial differential temperature gage purchase.

So what, did like no one install the gage?  Has anyone got any "deltas" for
the stock IC?

Which brings up a Question for the engineering types.  Since its the weekend
& football season's over I'll ask one:

Should one expect an IC's delta to remain relatively constant?  In other
words, on a 0 degree day, while cruising the highway under moderate load,
say @ a constant 70-75mph, I find that the Davtron is reporting an IC "out"
temperature running right around 7 to 10 degree above ambient.

Should one expect that difference to remain about the same on a 32 degree
day?
A 60 degree day?  Or does the cooling efficiency change with a rise in
ambient temperature?

i.e. On a 0 degree day, the incoming air charge at the air filter is roughly
0 degree.  By the time it passes through the turbocharger (hot), thermal
convection (just for arguments sake, I've no idea what a real world number
would be) raises that by say 10 degrees, and boost (pressurizing the air
charge) another 30 degrees for a charge into the IC at say + at 40 degrees.
Passing through the IC knocks that temperature back down to say 7 degrees,
for an IC induced change of -33.

Is it reasonable to expect on a 60 degree day ambient, the same differences
would apply?  Incoming 60 degree air is heated by thermal convection from
the hot turbo by 10 degrees, pressurization adds another 30 for an outgoing
IC temperature of 100 degrees which the IC knocks down to ambient (60) plus
7, producing the same -33 degree temperature drop?  I guess under the above
one would, or should assume a constant cool air flow / speed across the IC's
cooling fins.

Or do IC efficiencies rise with greater and greater charge air temperatures?