Intercooler Reference Notes

[bcl]

This post is intended to provide some general information about Intercoolers, via a web reference to the intercooler types that are available, so that we have a better understanding of Intercooler types and attributes.

The following link is to the ARE web site, a company that makes intercoolers:

http://www.are.com.au/techtalk/intecoolersMR.htm

There are 3 types of Intercooler:

1. Bar and Plate

2. Tube and Fin

3. Plate tube and Fin

The following quotes from the article are pertinent:

"Tube & fin cores penetrate the ambient air (channel the cooling air) better - less disturbance - than plate tube & fin cores which penetrate just better than bar & plate cores. "

"As a general rule, with a level playing field (manufacturing quality, both fpi's, tube size, thickness, & a hundred other variables), bar & plate intercooler cores dissipate more BTU's than plate tube & fin & then tube & fin cores - per square centimetre. Please stop, go back & read that sentence again, as it is the most often asked question, but the most misquoted answer of all time. Please also note that it is very easy to change just one specification of a core to make it better than the other (forget plate tube & fin here), & it must be remembered right now that heat dissipation is only one parameter of overall intercooler performance. If there is enough area & volume available, I mostly recommend a tube & fin core to do the job, as it will get the temperature down close to bar & plate, but at less pressure drop & less chance of leakage."

"Turbo Lag ? or is it

The internet is a great thing, BUT, there are so many false statements that people make sound so convincing. "I put a big front mount on my VL Commodore & there's no extra lag at all, it goes heaps better too". Treat this person with total distrust. The only accurate (note: I did not say honest, because he may be genuinely kidding himself) part is ' it goes heaps better'. It is a physical & scientific impossibility, to not have extra lag in this case.

If it was a Skyline or similar car, treat the person with some distrust & quiz them on both setups, as the system they replaced was certainly not optimized &/or the new system must be really suited to the car."

"Not all Chinese intercoolers are created equal. I can not stress this enough ! They do not come from the same factory. There are at least 8 factories that have contacted us with total different addresses & then there are different named companies within these addresses, which is how some flaunt the copyright laws that western compan - ies must abide by. A couple of factories make very good units, some are okay, & some are downright bad. To complicate purchasing further, some size intercoolers from the same factory are good & other sizes bad. How do I know this, we tested some 75mm units from an importer, which came up good in all aspects & unfortunately for us quite good in a couple of aspects, so they represented excellent value. We have sold a few of these without one complaint. They also imported some 90mm & 100mm intercoolers from the same factory. After getting some returned with vocal complaints because power output & response dropped when these were fitted (often replacing a 75mm unit), they sent one each up to me for testing. Just looking at them showed a close fin pitch. Results are listed below. We are talking all bar-plate construction with these imported intercoolers. The sad part of all this is there is no way of accurately listing who's who, most factories will stamp any name onto there product!

Intercooler - Size Type Flow Rate-corrected Notes.

Chinese 600x300x90mm. Bar-Plate - 3" inlet. 299.3 cfm

Chinese 600x300 x100mm. Bar-Plate - 3" inlet. 330.9 cfm.

ARE-610x302x91mm. Tube-Fin - 3" inlet 471.4 cfm.

ARE-610x302x91mm Tube-Fin - 3" inlet 493.3 cfm. With our optional venturie plate option"

"The intercooler cores produced by both manufacturers in Australia are extruded tube & fin design. There are actually 4 manufacturers of aluminium radiator cores in Australia - ADRAD in Adelaide, DENSO in Melbourne, K&J in Currumbin & NATRA in Melbourne - but only two of these will make a core to size (npn) & it also happens that the same two are the only ones too manufacture intercooler cores - ADRAD and K&J ! A variant of the extruded tube core is the folded tube core, which has two thinner wall sections with a seam folded to the inside, manufactured by Calsonic in Japan & fitted oe by Nissan - including the GTR. Bar & plate is most common in the USA. aftermarket (& strong in trucking industry), whilst the plate tube is common in oe. intercoolers in Japan - mostly Denso - Toyota & Diahatsu, & a couple of Mazda models. Japans aftermarket is more tube & fin than bar & plate when looking through the catalogues, with no aftermarket performance plate tube & fin cores from any country - thank goodness."

There is a lot more information available at the web site, including pictures and diagrams; well worth a read.

Brian

[Flukey]

Cooler is next on my shopping list so great info Brian.

Thanks

[Adam]

Good info Brian.

[normda]

wow. that's good info!

[MUZ]

What a great post, some good info

Muz

[Impellor]

Here is an update Intercooler list that simply highlights the approximate internal capacity of the listed Intercoolers. However, this will give some idea as to cooling efficiency of a particular product. Further, if anyone has a cooler not on the list it would be greatly appreciated if you could measure the dimensions and pass on so that we may add to the List, Cheers

FG - Ford XR6T 370 x 255 x 55mm = 5189 cm3 (Factory)

FG - FPV F6 370 x 380 x 45mm = 6327 cm3 (Factory)

FG Process West stage 1 & 2 420 x 410 x 90mm = 15498cm3

FG - HDI GT2 PRO - HYBRID LENGTH - 660mm x WIDTH - 80mm x HEIGHT - 440mm = 23232

BA/BF- Ford XR6T 368mmL x 178mmH x 51mmD = 3340 cm3 (Factory)

BA/BF- FPV F6 estimate based on being 50% bigger than the XR6T = 5,011.056 cm3 (Factory)

BA/BF Rajab Racing 406mmL x 305mmH x 76mmD = 9411 cm3

BA/BF APS 508mmL x 351mmH x 89mmD = 15869 cm3

BA/BF Monza 450mmL x 300mmH x 76mmD = 10260 cm3

BA/BF AVO 457mmL x 356mmH x 89mmD = 14479 cm3

BA/BF Nizpro 475mm x 430mm x 80mm = 16340 cm3

BA/BF Plazmaman 480mm x 300mm x 76mm = 10944 cm3

500mm x 410mm x 76mm = 15580 cm3

BA/BF/FG 1800hp 530mm tapering down to 575mm (ave used for equation 552.5mm) X 405mm X 100mm = 22376 cm3

BA/BF Process West Stage 1 420 x 360 x 90mm = 13608 cm3

Stage 2 500 x 370 x 80mm = 14800 cm3

Stage 3 500 x 425 x 100mm = 21250 cm3

BA/BF Hybrid 450mm x 300mm x 76mm = 10260 cm3

BA/BF Auto Sport Engineering (ASE) 450X450X76mm tube and fin = 15390 cm3

450X450X100mm bar and plate = 20250 cm3

BA/BF Hyperflo 480mmL x 400mmH x 100mmD = 19,200 cm3

Edited 16/01/12 07:18 AM by Impellor

[Dillz]

Good post, great to see them all stacked up.

[Impellor]

Little info for you Intercooler tech heads to consider, Cheers

Building blocks of intercooling.

If you think about it, trickery plays a big role in performance tuning. We fool the ECU into giving us more power with black boxes. We trick the fuel system into delivering more fuel by upping the pressure, and in the biggest con of all, we fool the atmosphere by compressing it and doubling and tripling its volume inside our engines. While forced induction is the big trick, intercooling also serves to befuddle the atmosphere in the name of power.

Intercooler Mission Statement

An intercooler's trickery centers on air density. During compression, charge air is heated and with this heat comes a decrease in air density. Density can be viewed as the amount of molecules in a given volume of air. Intercooling reverses the heating trend and endeavors to recapture some of that density.

The amount of density regained depends on the ambient temperature of the air (in air-to-air units), the efficiency of the compressor (max boost, wheel efficiency etc.) and the cooling capacity of the intercooler.

A properly sized turbo that operates at or near its peak efficiency will not heat the charge as much as a mismatched unit that has to overspeed to generate the desired boost. This extra effort results in a chopping of the air, which nets high outlet temperatures.Because of its charge chilling capabilities, the intercooler also ups the detonation threshold and, as a general rule, a good intercooler will allow you to run three to four more psi without experiencing any detonation.

The charge side is where boost...

The charge side is where boost travels to be cooled on the way to the engine. Here we see a fin comparo with the popular low-pressure drop, high-speed plain square fin (right) and an offset fin design (left). The offset fin will allow the air to travel slower through the core (more pressure drop) but the air will have more time in the core for heat exchange.

Construction Techniques

Intercoolers are constructed in a number of different ways. The most popular are bar and plate and tube and fin. We cornered Johnny Wang, Spearco's product manager of heat exchangers, in the intercooler inventory room and would not let him leave until he answered some questions

.

Tube And Fin

"A conventional tube-and-fin intercooler weighs less than a bar-and-plate design," says Wang. "Typical tube-and-fin units utilize extruded tubes with fins pressed into place. In order to achieve strength, a thick, extruded tube must be used.

"The tube-and-fin core is held together and its seal is created at the joints at the end of the plates, which is usually .125 inches thick. The width of the tubes is less than the width of the side plate. Space is lost where the joints for sealing are used. So a 3.5-inch core will have tubes only 2.87 inches wide."

Unable to maneuver around the machinery, Wang continued, "Also, fin design in the charge side, inside the extruded tubes, was limited by the extrusion machine, which impeded the design of charge side fin geometry to meet individual custom applications. While this design did allow varying ambient fin designs, the charge air shortcomings proved too much of a handicap.

"Tube and fin has a larger leakage rate compared to bar-and-plate cores. Furthermore, tube-and-fin cores are more susceptible to road damage from rocks and debris than bar-and-plate cores; big trouble in front-mount applications. The oval tubes are extruded from thin-wall material and any sort of extreme pressure can cause these tubes to 'balloon.' In today's high-performance industry, high boost levels are the key power."

On the ambient side, where...

On the ambient side, where oncoming air streams through the unit, fin design is equally important. Fin density here also impacts cooling performance but there is often the vehicle's cooling system to consider.

Bar And Plate

Wang had a more upbeat tone when it came to bar-and-plate construction. "Spearco pioneered bar-and-plate core design. True, the bar-and-plate design is a bit heavier than tube and fin, but this is actually advantageous.

"The core acts as a heat sink. Its ability to soak up more heat is especially useful in stop-and-go traffic. It keeps the charge relatively cool, then is able to dissipate the heat once the vehicle is in motion. Tube-and-fin units can't pull this off.

"A bar-and-plate core can take the damage of front-mount life and endure high boost without flinching. Sealing is superior in bar-and-plate units because the bars and brazing sheets run the length of the unit, providing a 100-percent seal between the ambient and charge sides.

Here we see a liquid-to-air...

Here we see a liquid-to-air core (left) and air-to-air units (right). A liquid cooler works opposite than a air-to-air in that the charge air is run through what would be the ambient side of a air unit and water is run through what would be the charge side.

"A key advantage of bar and plate is its extraordinary variety of fin designs on both sides of the cooler. Further, the height of the passages can be changed by using taller bars and fins, which dramatically expands the possibilities for the intercooler designer. A 3.5-inch thick core gets a 3.5-inch row of fins, not the 2.87 inches found in tube-and-fin designs.

"Also, a tube-and-fin design has a lot of room between rows where a bar-and-plate unit can get more rows into a given area with more area per passage which means more cfm and a more efficient unit. As far as big boost goes, the ability of a bar-and-plate core to handle high boost is determined by the thickness of the braze sheets, fins, side bars and top plates."

Density Dynamics

The intercooler is a crossroads of sorts. Charge air and ambient air intersect inside the unit and heat exchange occurs. The cooling properties of intercoolers are decided by its thickness (for charge air flow) and area (for cooling ambient airflow).

The thickness (and the type of fins used) dictates how quickly the charge air will move across the unit while the surface area affects how quickly ambient air will flow across the cooler. The curveball here is fin density. The number of fins per inch will dramatically impact the cooling characteristics of the unit.

The popular plain square fin...

The popular plain square fin works its magic on the charge side.

"Fin combination is very crucial when designing an effective core with a very low pressure drop," says Wang. "A dense fin design offers superb heat transfer, however, this design also creates high pressure drop. Pressure drop is the amount of boost lost by the system as it pumps the charge air through the intercooler. The type of fin-plain, offset, louvered or bump-each has its own unique heat transfer characteristics.

"The key when designing any intercooler is that a median is met where the effectiveness is attained and a low-pressure drop is achieved. For example, a plain fin design offers an exceptional low pressure drop but does not provide great heat transfer compared to a louvered fin or an offset fin. The air moves quickly over/through the plain fin (low pressure drop), but is so fast it may not be in the core long enough to maximize heat transfer. Consequently, air moving through a louvered or offset fin takes longer to move through the core (more pressure drop), but it also has more time to transfer heat."

Area vs. Thickness

Wang continues, "The rule of thumb here is obvious-bigger is better. More surface area means more cooling power. However, a larger surface area is favored over a thicker core. A larger surface area provides more cooling face for the ambient air where a thicker core might be less effective. As the core gets thicker, the ambient air traveling through the core is heated by transfer and the farther through the core it travels the hotter it gets. By the time the ambient is at the back side of the unit, it's lost a good percentage of its cooling capacity. Beyond that, thick cores cause an ambient pressure drop, which means less air will make its way to the radiator causing overheating issues.

"When it comes to area, achieving the maximum height is more beneficial than widening the unit. The main reason for this is pressure drop is greater when the charge air has to travel through longer passage compared to a shorter passage. It should be noted that pressure drop through a longer-passage core can be compensated for, to a certain extent, via fin design."

Here we see an ambient side-louvered...

Here we see an ambient side-louvered fin.

Spearco produces both tube-and-fin and bar-and-plate intercoolers. With bar and plate being so superior, one has to wonder why. It's all about cost. The tube-and-fin core is much cheaper to produce and is often used in OE applications, which inherently run lower boost levels.

Spearco put a new twist on tube-and-fin cores with its extruded tube design that incorporated the fins as part of the extrusion. In this design, the overall weight was about equal to a bar-and-plate core. tube-and-fin units are cheaper to manufacture.

This is an ambient side-split...

This is an ambient side-split fin.

Manufacturing Methods

Generally, two manufacturing methods are used to create intercoolers-vacuum furnace brazing and controlled atmospheric brazing (CAB). Vacuum furnace brazing starts with a "Lego set" of parts that are stacked and strapped together, then placed in the furnace. The headers, fins, bars and plates are aligned with a thin layer of aluminum cladding positioned in between. This clad material is designed to have a melting point slightly below that of the intercooler components. With the straps providing the proper amount of pressure, the furnace "bake-welds" the parts together in a totally inert environment (less oxidation).

CAB is very similar to vacuum furnace brazing but the component parts are dipped into a cladding solution and then assembled in the furnace. Instead of a vacuum, CAB furnaces are purged with nitrogen. Coolers made with this technique have a chalky look to them, while vacuum furnace brazing leaves more luster.

Spearco's extruded tube charge...

Spearco's extruded tube charge side tube. Generally, tube and fin offers cheaper manufacturing costs, but makes compromises in durability and high-boost pressure capability.

Popular cars have intercooler kits designed especially for them, but custom applications and special circumstances may mean starting from scratch. Spearco has proprietary modeling software that will crunch the pertinent numbers to meet the cooling needs of custom applications.

Intercoolers do a lot more than look good behind a custom bumper cover. Their atmospheric trickery is the result of technical factors such as area, thickness, fin design and fin density. Controlling the flow compromises and cooling advantages of these factors will determine the ultimate driveability of your turbo system. The payoff is power.

Read more: http://www.turbomaga...l#ixzz1jbgcblVn.

Edited 16/01/12 08:19 AM by Impellor

[arronm]

Great information, BUT people must understand size alone doesn't equal flow or efficiency.

[Impellor]

The article above goes along way to explain the facts. I used this article as it was the best I found, and clearly highlighted that the manufacturer actually made both intercooler types. I also feel that it conflicts with a previous acticle by Brian and goes a long way in dispelling some of those claims. I personally feel that this is a more accurate summarisation. Some of the areas that I found interesting related to the fact that greater thickness reduced efficiency and that greater height played apart in obtaining better results. And finally it looks as though the Bar and Plate is a better option for a road car, being better for traffic conditions, and providing greater durability and strength. Cheers