Mad Cow

Let's take an intercooler that's rated for 300 horsepower.

What is the limiting factor? Does the intercooler now physically flow enough air, or is the intercooler just not cooling the air enough because the air is moving through it too fast? (not enough surface area)

If it's not cooling the air enough, can you datalog your IAT to see if the intercooler is still efficient? What's a good range of temps for the IAT to read?

89civic1.8T

I would like to know also. How is the precision intercooler (24X6X3.5) rated at 350 HP when the drag gen III IC is rated at 500 HP? The Drag IC is 1 inch thiner.

Mad Cow

Up to the top. Someone enlighten us.

Blaze45

bump cause I wanna know as well,

Blaze

RedTegLS

I think its all based upon how much boost your running. A 6" tall and 2.5" thick IC isnt going to be able to cool 12lbs of boost as efficiently as a 8"x3".

Mad Cow

Yeah, but that's because of a simple surface area calculation... not really what I was looking for. Bump.

rjardy

I think that the cfm capacity is alot to do with it. Not sure just throwing it out there.


Rob

JrCRXHF

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MadCow &raquo;</TD></TR><TR><TD CLASS="quote">Yeah, but that's because of a simple surface area calculation... not really what I was looking for. Bump.</TD></TR></TABLE>

last i knew it was a surface area deal you can only effectively cool so much air what makes them work is simple t1-t2 the colder u can make t2 the better.

or that is how i have always looked at it..

Mad Cow

ALright, well if that's the case, what's a decent range for your final (intercooled air) temperature?

raene

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MadCow &raquo;</TD></TR><TR><TD CLASS="quote">ALright, well if that's the case, what's a decent range for your final (intercooled air) temperature?</TD></TR></TABLE>

Personally I would think getting in the 80% efficiency range would be nice... at least 80%. Depends on ambient air temp and airflow characteristics of the mounting location, I suppose.

Mad Cow

So when an intercooler becomes ineffecient, it won't restrict air flow, it will just not cool enough?

Or does it limit air flow too?

tjbizzo

IMHO the best intercooler designs (for a given frontal surface area, like 6"x30") have lots and lots of tubes that aren't too long. Why you ask? Consider two 6"x30" intercoolers, one has 6" endtanks on the left and right with tubes 30" long, and the other has 30" endtanks on the top and bottom with 6" tubes. In which one does the air stay in the tubes the longest? It's a trick question because the air stays in the tubes of both ICs for the same amount of time. YES, it does, and here's why. In the long skinny IC the air is going 5 times farther but also 5 times faster. In the short fat one the air is going 5 times shorter but 5 times slower. Are they equal? No. The long skinny one creates MUCH more drag and pressure drop than the short fat one, so you need to create more boost pressure, and therefore also heat, in the turbo of the long skinny one to get equal boost pressure in its intake manifold. And that's IF you can cool the air as much, which you can't. The downside of the short fat IC is that they cost more and they weigh a pound or two more than the long skinny one.

Also IMHO, unless your IC is bigger than your mattress it isn't too big. Some guys will say that a bigger IC creates lag but the lag due to the difference in internal volumes is almost insignificant compared to the inherent lag of the turbo itself. Of course, buy what you want, it's your money.

Mr. Softee

Art has posted this before, it has to do with pressure drop/efficiency from an IC as well. Basically some IC's cannot physically flow enough air to produce X # of HP. The tubes the air flows through are obviuosly not very big so if you have a small IC there is only so much air that can flow through it before you reach a point of diminishing return.

Blaze45

Bump for more info.... thanks to all those who contributed...

Blaze

beepy

If you want the scientific explanation, here goes:

There are two things that a intercooler directly influences. Heat and pressure.

Pressure is influenced in two ways. One, is the pressure drop that occurs because the intercooler has a larger internal volume per unit length than the pipes that go into and come out of it. Dynamics would tell you that pressure would drop, and then rise coming out of the intercooler, and for the most part it does, but because of friction and other ineffeciencies the pressure is always lower.
Secondly, the pressure drops by virtue of the air being cooler. This will always occur even in a perfect system, so no intercooler can ever be 100% efficient.

So, how do you maximize cooling while minimizing pressure loss? Simply, you want to have the largest surface area possible, with the least internal pressure and an internal volume per unit length as close as possible to the charge pipes. Since larger turbo systems need larger charge pipes, so the intercooler much get larger.

Thus, intercoolers that are "rated" at 300 horsepower are likely much larger than ones for 150 horsepower. Using too large of an intercooler will cause an unwanted drop in pressure, using one too small will limit surface area and increase internal friction.