[s-cars] FMIC info digested...

[Marc Swanson]

On Tue, 2005-11-01 at 23:39 -0500, djdawson2 at aol.com wrote:
> OK, let's say "inefficient."  It's a well established fact that the tube and fin IC doesn't perform as well as a bar and plate of equal size.

You're missing a few advantages that tube and fin intercoolers enjoy:

- less restrictive (lower pressure drop)
- less mass (lower weight)


Bar and plate ICs are physically more massive than tube and fin and as a
result, they hold more heat.  This can actually be a liability,
especially considering situations such as drag racing.  You'll spend a
good 10 minutes miniumum getting your car to the starting line.  During
that time, your intercooler has soaked up as much heat as it possibly
can, and will likely spend the fist 100' or so getting rid of it whereas
the tube and fin core has less mass and thus would take less time to rid
itself of the accumulated heat.


>   You can read about it anywhere, and often... so why would one choose that route?

I'm not doubting that bar and plate is more efficient, because it is.
But there are other factors involved.


>  
> Bar and plate intercooler cores function basically the same as a tube and fin core. In a bar and plate core, the charge air travels through passages that have more surface area... about a 35% larger surface area for cooling.  Yes, you CAN have a tube and fin IC that provides good results.  However, if you are limited in space (and we are) a tube and fin of size "x" will never provide the same heat transfer capability of a size "x" bar and plate IC.
>  
> Another point to consider is the mass of the BAP, compared to the TAF.  TAF cores are very light... whereas the BAP is quite heavy.  The BAP has a substantial ability to "store" energy... using it for those typically short periods of high output.

See above.  I see that as a liability.
 
> As a data point... see if you can find an OE tube and fin IC in any German performance car.  I certainly haven't seen everything... but in everything I have seen, it's been bar and plate.

Just going off of what I've had in my hands, the UrQ is tube and fin, as
are the big diesel truck ICs.
 
> But hey, YMMV, and if you like tube and fin, go for it.

I think I'm just trying to level the discussion and point out that bar
and plate is NOT necessarily better, hands down, no questions.


--
Marc Swanson
95.5 //S6 Avant
90 CQ 4.2 V8 project car