intercooler thickness. How thick before it loses effeciency?

[W.P._Turbocars]

Just picked up a cooler that's overall a little bigger than the precision unit on my truck now but instead of 3" thick its more like 4.5"to 5". I didn't have a tape measure handy but it's definitely more than an inch thicker. I was debating on running a separate cooling fan on it to help pull more air through which shouldn't hurt anyways but is it necessary?

Thanks guys.

[johnl]

I'd run a motorcycle radiator fan on it, maybe with a Hobbes switch as boost comes on.

[W.P._Turbocars]

I'd run a motorcycle radiator fan on it, maybe with a Hobbes switch as boost comes on.

I figured it have it kick on with my regular fan for the radiator. AZ gets super hot. Pics too when I can.

[4 l-bodies]

Once upon a time Spearco had nice charts for all their intercoolers that showed pressure drop by PSI and efficiency of intercoolers by MPH across core. It was pretty interesting. The beauty of the thicker core is why it may not be seeing full ambient air temp. all the way through the core, it most certainly is acting as a great heat sink.
Todd

[Vigo]

I now think of intercoolers as having two distinct functions: First, to soak heat out of the charge air, and Second, to transfer the heat to outside air.

Those two things could happen at substantially different rates. The first is definitely the more important of the two for a street car that never sees full power for more than 15 seconds at a time.

One situation that is analogous to the 4"+ thick intercooler core in question is the people who have doubled up stock T2-style intercoolers to be double thick and still fit in the stock location. 2.216vturbo did one on his rampage and claimed a lot of power gain by the butt dyno. There is a guy named SVOdave who had one in his lancer which worked well enough for ~13 second power levels before he sold the car and it was sort of de-modded (i now own that intercooler but havent used it yet).

[Ondonti]

How much of that pressure drop is mitigated by PV=NRT? Pressure drop is often talked about as a measurement of restriction but I don't see a large intercooler causing increased restriction, just delayed response. Say your little "well designed" intercooler has low pressure drop, then run twice the air through it and see what happens. Try the same amounts of airflow with a giant intercooler. Then think about the exchange of heat, density of air vs actual air pressure, etc.

I wouldn't fit an intercooler that large on a car making 1/3 the HP it might support. I like the idea of going bigger but a 12x3 is bigger than any stockish setups need and sufficient for most everyone at the top. The problem would really be if they heat soak or not and if the surface area of all the internal and external fins working together with the airflow that you are able to FORCE through the intercooler to will be enough for the heat you need to get out.

The dyno record holding Subaru back in ~2008 had a cheap 12x4 intercooler that worked fine on the dyno but at the end of the 1/4 it would heat soak and cause problems...and that was not even full boost.

[johnl]

I'd run a motorcycle radiator fan on it, maybe with a Hobbes switch as boost comes on.

Good points all around, that said, ditto me. lol

[W.P._Turbocars]

Good points all around, that said, ditto me. lol

So then, next question, build a shroud for it or leave it open air around the two fans? I'm opting for a fiberglass shroud probably since I work with a guy who can glass anything.

[Ondonti]

Ducting. That would make you one of the 1% of people who actually install their intercooler correctly. I never have bothered.

[johnl]

Most of the motorcycle fans come with their own limited shrouds which also serve as mounting brackets. That is, they come with light sheet metal stampings that both shroud the fan and mount the fan motor and typically they also have nuts welded to the brackets. So . . . you can adapt them, weld on them, extend them, shorten them, and so on.

A fan could block air too Since at some speed the wind through the IC might possibly exceed the capacity of a fan, maybe don't shroud completely, figuring that that the fan with its limited but focused shrouding is going to suck heat out of at least half of your intercooler's area. If you can fit two fans, then . . .. yeah a full shroud might be best.


Also, if there is a way to shroud, or focus, the incoming air at the front of the car, I'd do that too, and then take that into consideration regarding the fan.

[johnl]

Here are two Denso fans from a couple of Kawasaki 500 twins that were at the junkyard. I trimmed the shrouds' brackets, used the tin I cut off to make the mounting brackets, and split some 1/8th rubber tube to cushion/seal the shrouds' contact with this air/water IC heat exchanger. This exchanger is not very thick, so the exercise is likely unnecessary but . . . . every little bit helps . . . and it's fun to talk about.

[Ondonti]

Sorry, by shroud I really meant ducting towards the intercooler, that is what people should be doing

[contraption22]

Fan shrouds can boost the efficiency of a fan greatly at low vehicle speeds, but can become a restriction at higher vehicle speeds.

Many circle track cars and road race cars do not use back side fan shrouds to maximize airflow at high speeds.

Street cars that spend time a lot of time at low-or no-speed benefit from fan shrouds the most, but even the OE's have incorporated flaps in the fan shrouds that open up to let air through when there is more ram air available than the fan can flow.

Brent's suggestion for proper front-side ducting is key. The intercooler core itself is a restriction to ambient airflow. Don't give the air an easy path to flow right around it, because it will take it.

[thedon809]

Now that you mention it, my neon had flaps. I have not seen any modern mopars with flaps though.

[Oggie Fisher]

The Dart has active grill shutters.

[thedon809]

That does the opposite of the flaps though. It restricts radiator flow to increase aerodynamics whereas the flaps in the cooling fan shroud increase flow through the radiator at highway speed.

[2.216VTurbo]

I now think of intercoolers as having two distinct functions: First, to soak heat out of the charge air, and Second, to transfer the heat to outside air.

Those two things could happen at substantially different rates. The first is definitely the more important of the two for a street car that never sees full power for more than 15 seconds at a time.

One situation that is analogous to the 4"+ thick intercooler core in question is the people who have doubled up stock T2-style intercoolers to be double thick and still fit in the stock location. 2.216vturbo did one on his rampage and claimed a lot of power gain by the butt dyno. There is a guy named SVOdave who had one in his lancer which worked well enough for ~13 second power levels before he sold the car and it was sort of de-modded (i now own that intercooler but havent used it yet).

No I didn't dyno it before or after but this helped a ton

[OmniLuvr]

^and you even passed the California smog natzi visual inspection with it! I think?