Aluminium Radiators & Engineering Pty Ltd
Unit 11 / 60 Kremzow Rd
Brendale QLD Australia

Ph +61 07 32054620 Email info@are.com.au


A must read....

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Obviously if you've landed on our website, then you have some interest in our cooling products.  It can be seen from the content and effort put into our website that it is designed not only to promote our products but also to educate you, the customer.  

The information below is my opinion on intercoolers, based on the experience and sights we see everyday at work, our hundreds of hours on the flow bench, & all the times at a dyno with accurate digital, both probe & infra red,  thermometers.  We hope this will help you in choosing which type of intercooler  is best suited to your performance requirement, pocket, driving style & car.

 

 

Before we start, remember that almost every motorized component is a compromise to some extent. Adding an intercooler to your super/turbocharged engine costs power & throttle response whilst in vacuum & very low boost! Fit an intercooIer to a naturally aspirated engine & see what it does to the power output curve. For a couple of decades when nearly all competition & modified street engines in Australia were naturally aspirated, opening up the ports or at least matching them with the intake manifold was almost mandatory. So we worried about a small mismatch of usually no more than 0.5mm. then, but some people now buy a great monstrous chunk of alloy that tortures the same intake charge (& isn't cheap) without much thought at all ! An intercooler causes a static pressure drop across the core because  of the extra resistance of the Intake charge "rubbing" on the internal walls of the "tube" & cooling "fins/ribs" create. This can vary  between approximately 0.3 to 5.0 psi. static pressure drop. The trick is too cool the intake charge the most, with the least static pressure drop. The more temperature that is pulled out of the intake charge, the higher the dynamic pressure drop has to be, because the cooler air is denser & occupies less volume. Simple physics. To judge a core properly on pressure drop, you have to know the static pressure drop & subtract it from the dynamic pressure drop, with the higher resulting figure indicating a more efficient core - the exact opposite to what you may first think. The denser the air, the more oxygen ( there is approx. 22 % oxygen in the atmosphere, & it is only oxygen that will burn in the combustion mixture), the more kw. produced. A rough rule of thumb is for every 10 farenheight - 1% extra kw. is produced ! So even though it does theoretically cost power with pressure drop, the denser intake charge easily compensates for this, with a power gain between not much to a bloody lot, realized !! The more the charging device beats & heats up the intake charge, the higher the power gains from intercooling & more importantly to me, the safer (engine component life) the gains are made. No point in winning the race back to the mechanic for a new headgasket , or worse, a new set of pistons, each time.

The heat from the intake charge is dissipated by contact with the surface of the interior walls (fins or extrusions), and then it transfers through the thickness of the "tube" wall to the surface of the exterior fin, from where it is transported away by the passing ambient air flowing through the core.


It seems that due to the cost of new fabricated intercoolers, a lot of people are looking for a cheap alternative.  However, as the old saying goes, 'you only get what you pay for' and usually the same applies to intercoolers.  There are significant differences in intercoolers, not only in core construction (bar and plate or tube and fin etc.), but also their design (especially end tank design).

There is usually a reason for the cost involved in buying a new intercooler (whether it be ARE or another company), and they do offer advantages over other options, especially cut down truck intercoolers

ENGINE DESTRUCTION  ! ! ! !

The most single deadly forced induction engine destroyer (apart from no oil) has two common names :-   Detonation or when I did my time at college, Pre Ignition. My interpretation of these is when the spark plug ignites the intake charge, the flame front travels rapidly but smoothly, across the piston face to fill the combustion chamber with the exploding fuel charge & force the piston back down the bore. When something happens to destabilize the smooth travel of the flame front (wrong combustion chamber/piston dome shape, little/no squelch surface, sharp edges, hot heat range plugs, advanced timing, excessive compression, high boost, too low octane fuel,) one or more smaller fronts can start & these then collide, resulting in an early &/or more violent explosion, resulting in the knocking or pinging noise that sometimes can be heard from the top part of the engine. Interestingly, it is easier to hear a standard car/ute ( our terrible unleaded) pulling away from the lights up a hill, than it is a turbocharged car. I have to admit that I lost an engine of mine only this year,  whilst testing on the open road (steepish hill) without hearing it. Radio on low & passenger reading data, I felt the engine nose over but by the time I clicked it & coasted to a stop, it was missing on one cylinder - side gone out of the top of the piston - expensive! That quick. Don't pass me off as a dickhead & it wont happen to you, be aware. The boost gauge decided to read at 60% of actual boost sometime just before the testing started, I adjusted it up thinking someone had changed it & it's that simple.  The cooler the intake charge - the less chance you have of detonation !  I'm also positive that a consistently stable (air/water is supreme here) cooler intake charge also increases the life of headgasket, valve & seats, top bore-ring-ring land to a noticeable degree, whilst offering considerable more power potential.  How important is intercooler selection now ???? 

Bar and Plate,  Extruded Tube and Fin,  Folded Tube & Fin or Plate tube & fin?

115, 90, 75mm bar/plate on left & 73, 57, 3mm tube/fin on right.

Close up of  bar/plate (heavy) on the left & tube/fin (tough) on the right

Nissan folded tube & fin on top. Adrad on left & K&J on right bot. - both are extruded tube - tough.

Denso plate tube & fin. Too many seams + too weak. Usually small thinner tubes with close fine fins.

                                                                        

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.

AIR FLOW.

  ADRAD      K&J    CALSONIC
     OURS   GARRETT       DENSO

The above pictures show how in all the different intercooler design/production methods, one  basic feature is common to all - the Ambient air flow is at ninety degrees to the Charge air flow.

AMBIENT AIR FLOW

Tube/fin top core & bar/plate underneath. These are average fin pitches, but if needed, we vary them to suit the purpose.

Our bar/plate top & Garrett below. Ours does not have as close fpi & being neat, allow more air through to the radiator

May 2002 HOT4's - tiny tubes with large ambient fins like this should only be for an air water application

  

May2002 Hot4's -super wide fin spacing like this could only be for extreme high cfm @ low temperature, or cheap !

Adrad tube. Ambient air brakes off back of tube good.

Denso tube. Air brakes off back of tube good.

Garrett tube. Air brakes off back of tube okay.

K&J tube. Air brakes off the back with highest drag, negating the benefit of best entry performance

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. Remember that in front mount applications, this has a small effect on the engine water temperature, by slowing the air speed & volume, before it reaches the radiator. This is because the rounded leading edge of the extruded tube parts the air with less turbulence than the "W" shape of the plate tube & fin core, only because this core has thinner tubes than the other two. If the square leading edge of the bar & plate tube was as thin as the plate tube, then it would flow better, but it comes a close third. The above drawings illustrate the turbulence caused by the three tube shapes. Please note that with the leading edge of intercooler tube shape, we are talking very small differences between them with tube pitch (spacing) having more effect than tube shape on ambient air flow, and it has little effect on charge heat dissipation, actually having allot more of an effect on radiator cooling efficiency.

One point often overlooked is the body work across the front of the vehicle.  Modern car designs have evolved to aerodynamic swoopy nosecones, which look great & give low  drag coefficients, but make intercooling & efficient engine system cooling, much more a science than a few years ago. Most of the current designs rely on a low scoop just in front of the radiator for the majority of air flow, so this has to be taken into account when mounting the intercooler. The less direct path the ambient air travels to the intercooler, the slower it's speed & so it's ability to force it's way through the core, resulting in both core thickness & fin pitch choice being much more important.  Surface area should be increased to compensate when core thickness &/or fin pitch are reduced & ducting fabricated to channel all air possible to the core & then through the radiator. . The same goes for Cars/four wheel drives that have driving lights, winch etc. mounted in front of the grille.

CHARGE AIR FLOW 

Below is what the intake charge see's.

                               Tube/fin core   Picture - Driftking

                                  bar/plate core    Picture - driftking

          Much more important (to performance) than the ambient air flow disruption is the charge air flow disruption entering the core flow passages. Least effected (as manufactured) is air entering the plate tube & fin core as the plates are stamped with a small radius as part of their construction & the fact these tubes are always allot narrower, however, check the paragraph on tanks before getting too excited.  Bar & plate cores are next, as the top surface is flat with a sharp 90 deg. edge. Tube & fin cores (both types) are definitely the worst as the tubes are proud of the header plate  causing some of the charge air to do a 180 deg. turn at the plate then another 180 deg. turn to enter the tube. Allot of turbulence/drag/static pressure drop! Most manufacturers of these cores take the safe/fast way in production & cut the tube lengths longer than necessary, hurting air flow, but knowing that the product is integrally sound. The tubes usually stick up around 3-4mm, which makes the air flow do 2 distinct 180 deg, turns. The cores out of the new Adrad factory are no more than 1mm proud of the header plate, so they have really tightened up there production tolerances. ARE. has a "venturie plate" option that gives the air flow a proper radiused entry into the tube, increasing air flow by approx. 8.4%. @ 10psi., an extremely worthwhile gain,& the only manufacturer I know of doing this ! Once again Lateral thinking & R&D gives our customers an advantage.  

 To size an intercooler properly, the most important factor is what I call " the charge air window". This is the  surface area of the tubes for the charge air to enter. With cores from the same manufacturer, just multiply the core height by the thickness, but too compare cores from different manufacturers properly, you must work out the surface area of each tube (allowing for fin/ribs etc.) & count how many tubes in each core. The window controls two parameters, - the pressure drop of the air entering the tube, so if he window is too small for the cfm flow, the pressure drop increases. Most importantly, if the window is too small, the air speed through the core will be too high & not allow enough time for the heat to dissipate out of the charge. If you play it safe & go too big in the widow size, then the tube length needs to be kept short, or pressure drop increases for little extra cooling. Best way is too size the intake window for the cfm. requirement, then the length of the tube for the heat dissipation requirement. That is for the same kw. output, a larger turbo needs a larger window & a smaller turbo needs a longer tube - generally.                 

 

COOLING CAPACITIES   (following some very contentious paragraphs)

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.

The most consistent method of charge air heat transference is Extruded tube. This is because the aluminium is forced through the extrusion die during manufacture, giving a 100%  wall to rib bond as there is no join in the material. The next most consistent is the "square" shaped fin, as it is stamped with a flat surface to fuse onto the tube wall, giving up too 10 times the surface area to bond to the tube over the least consistent, folded fin, which is the most common in bar & plate, & all that's seen in plate & fin cores. We have seen intercoolers where the tolerance of the fin fold width is too narrow & so the fin didn't fuse too the tube wall, resulting in no heat transference in that area. Also the fins can bunch up, leaving a gap either side, very inefficient. Another reason for the difference in the price of cores - quality control against sloppy manufacture.  

The most efficient method of Charge air heat entrapment is folded fin, because louvered fin configurations &/or very close fin per inch ratios can be utilized, resulting in higher surface areas to "grab" the heat. Note that these also cause the greatest pressure drop. It really comes down to manufacturing quality & specifications between folded fin & extruded tube efficiency as they can give similar results. Some folded fins have holes to break up the air flow, some have louvered fins to channel the air & some are plain flat, but they usually have higher fpi. ratios. Extruded tube dividing walls are either flat or have ridges running length ways for increased surface area. 

         Below are 5 pics of different bar/plate cores. You have to know all the specifications to be able to accurately judge which core suits your application best, Then there's tube/fin !!        

   

 Our 3rd. generation bar/plate on left compared to best the same factory offered on right. Big difference in performance. Both a larger tube & more fins = cool

   

Top is narrower charge passage to ambient ratio compared to bottom. Note bloody sloppy quality of bottom core!  We have to straighten fins before welding tanks on.

    

On the left is a louvered fin (more cooling & pressure drop) & on the right is punched fin. Different results.

May 92 HOT4's shows ridicules course finning I can't think of any application for this except cost. Not even air/water.

May 02 HOT4's shows three examples of course finning which is inefficient, cheap, & flooding our market. Be wary !           ******CHEAP can mean            HEAT*******

 

Three different bar/plate core from 2 different manufactures. Note the very small "tube" size for water cooling in the air/water core. Also the courser fpi. of the Spearco air/air core

There are some cases where I will definitely not recommend a tube & fin core & they are where there is not enough room for a properly sized core, usually upgrades in the oe. position - Subaru top mounts, S13,14,15, Skyline GTS, 300ZX inner guard etc. or big kw. applications. The thickest tube & fin core made in Australia is 75mm & there are allot of applications where that will not allow large enough intake window area size, causing a pressure buildup in the inlet tank with the charge trying to get into the tubes & too high air speed through the tubes, to be able to pull the heat out of the charge. Note: This has now changed as of August 2002 with ADRAD producing 109mm & 146mm thick tube/fin, & having instigated & played a part in their development, I mostly recommend these cores except for extreme cfm & heat applications ie: very large turbo's working near or above their efficiency range, size not available or not enough room - header plate size. It is impossible to repair a leak near the centre of a thick core, & because tube/fin is both stronger & less prone to leaks, they get my vote. I have not made any mention of the plate tube & fin core, because to my knowledge, the Japanese plants only supply to the oe. industry & do not sell to the aftermarket. For overseas customers, I have seen thicker tube & fin cores made in Japan & I imagine these could be a viable alternative. 

An advantage of the bar & plate core  is when there is a lack of room situation in thickness at the tank ends, as a tube & fin core has to have the outside of the tank at least 6mm proud of the tubes on each side (absolute min. 87mm tank on a 75mm core), whereas the tank can be a few mm inboard of the bar & plate core 86mm tank on a 90mm core). This can be very important in cars with short engine bay/grille areas (Datsun 1600, Hi Lux etc.). 

Note that usually, the more surface area, the higher heat transference, but also the greater pressure drop. There is no across the board, standout performer in the above three cores, as they all have there strength & weaknesses, but it is a two horse race, as plate & fin cores are only available oe., meaning smaller sizes for lower kw. applications. They have too much static pressure drop & are too weak to be manufactured in large sizes. You will have to add you own interpretation to what the company you are dealing with has to say, & hope they know exactly what they are talking about 

Plate tube & fin tanks, for charge air flow, are a basic disaster with the high capillary turbulence caused by the approx. 240 deg. convoluted walls causing a large static pressure drop. I have never bothered to measure the flow drop because there is no point - only used in oe applications, thank goodness. Sorry  Denso, but that design is a shocker, it should be left to oil coolers, if at all ! These must have been designed by accountants.    

                                                                                                                                                                                 

   Core Construction

115, 90 & 75mm bar/plate on left. 73,57,37mm tube/fin in right.

Our bar/plate on the left & K&J tube fin on the right.

 Nissan skyline oe on top. Adrad on left & K&J tube/fins on right.

 

Real close up of the three different header plate designs.

Difference  in fins & tubes between K&J closer & ADRAD cores, even though both are tube/fin

The extruded tubes. Integral strength over bar/plate. We remove any swarf before welding or it's straight into your engine !

When I was in the factory, we discussed rib size, flow tested the tubes & this is the result - 1.28mm ribs instead of .80mm 

                     Plate tube & fin cores are the physically weakest core in that we have allot more of them come through our workshop for repairs than any of the other three, & too reinforce that, they usually have a larger leak for the damage &/or the leak be further away from damaged area. The core has three components too each tube. Two stamped side plates with fine folded fins fused internally. I believe the plates are "stretched" too far to form the tank on each end, thinning the alloy to where it will crack with minor stress. They are clamped together (looking like a piano accordian) & furnace brazed.                       Bar/Plate & fin cores are the second weakest, even though they are also the heaviest with a couple of the thickest components. However this is the reason for their weakness. The thin plate side walls have to fuse onto the thick plate sides to form a "tube", with both of them having to fuse onto the very thick bars to form the "header plate" for the tank to be welded to. It is hard for these three differing thickness to be held at the right temperature for the cladding to melt,     ??   & fuse the surfaces together. This is where we see most of the leaks in these cores, even from new in one brand. The charge cooling fins are fused to the thin plate walls, meaning there are 5 components too each tube, a reason that these cores tend to develop a series of weeps along the "header"  seam.     

                       Folded tube & Extruded tube seem to be of similar strength although with two tube sides, fine fused internal fins & two header plate joints, folded tube should be weaker with 5 components. However, I have seen both types of cores come in for repairs quite beat up & out of shape, without leaking. Eventually the hot/cold & pressure/vacuum cycles will open up cracks.                                                                                                                                                                                      The Extruded tube core is possibly the strongest core as it only has three components in it's construction, a tube & two header plates. It is also the most consistent performing unit as the internal charge air cooling ribs are one piece with the tube walls whereas the above three cores have tubes with fins fused too them & if the specifications vary in production for any reason ( & it does occasionally), then an area of fins can exist where they are not in full contact with the tube wall, bottling up the heat in that area. The same also happens with external ambient finning, although this is common to all four cores & can be found with a simple visual/physical check.

 Header Plate/tube joints, bar/plate joints

Bar/plate top & tube fin bottom. Note how the header plate is proud approx. 7mm/side making a wider overall 'cooler. 

Same pair intercoolers from opposite direction. difference is more graphic.

Folded tube/fin on top is okay, tube/fin bottom left is best & right is worst for air flow entering tube.

Bar/plate on left has intergral header plate, whereas tube fine has to be proud to weld  tank to.

The 8 components that make a complete tube in a bar/plate core

The 2 components that make a complete tube in a tube/fin core. Note flux/cladding around tube.

The 3 components that make a complete tube in a folded tube/ fin core. This has a tabbed header plate to hold tank on.

The 2 components that make a complete tube in a plate tube/fin core, including the tank - shown cut in half here.

I have not worried about fin/ribs in the above pics. as they are common too the internal structure of every tube & would unnecessarily clutter the pics. They are highlighted in their own section.

 

  Finning - or Ribs.

Both Adrad cores. Different fpi.'s for different applications.

Adrad top & K&J  bottom, different fin shapes & pitches.

Garrett top & ours bottom. Straighter uniform fin allows more air through.

Charge air fins, straight uniform fins allow intake charge through with less pressure drop.

More open ribs of Adrad give 17% less pressure drop. Radius on ribs adds to surface area.

Longer ribs help pull heat out of air better, but more restriction.

Cut away bar/plate core shows fins at 90 degree to each other, very efficient but high pressure drop.

This is actually an abient air fin, but very similar to charge air fin. Louvers direct air flow but also cut flow dramatically, so fpi important

The parts  of an intercooler that do all the "work" are the fins, or in the case of extruded tubes, ribs. Their purpose is the opposite when in charge air flow to ambient air flow. In charge air flow, their job is to soak up the heat in the passing air & deliver it to the tube wall. The trick is too pull the maximum heat out of the air with the least resistance to flow. The different designs are flat fin (cheapest & least effective), punched fin & closely followed by louvered fin (dearest & most effective at heat soak but with highest pressure drop). Extruded tubes are formed by forcing an aluminium block through a die resulting  in a complex one piece tube, offering 100% heat transfer between the rib & tube wall. This does not always happen with fins, because sometimes the factory does not apply the correct "crush" to the core when clamping in assembly, resulting in no bond between the tube/fin during furnace fusion. It appears to be more of a problem with internal fins than external, but luckily, is not that common. Extruded tubes have internal walls that form continuous compartments with ribs inside each compartment. These vary between manufacturers, but the same rules apply - more ribs/inch, more heat soak & pressure drop. Also the more ribs in contact with the tube wall, the more efficient. Because of the extrusion process, ribs are thicker than fins & there is always more open space in the middle of the tube. This results in a small reduction in heat transfer if the tube is too long, as the air " straight -ens out"- reduces turbulence due to the smooth compartment & rib walls. With Ambient air flow, the fins job is too radiate the heat, so the air passing through the core absorbs the heat & transports it away from the core - usually straight into the radiator finning - but that's another problem! Adrad fold both fin edges over (hem the fin) which doubles the strength fin & lessens damage. Damaged fins should always be straightened as they inhibit air flow & so cooling efficiency.  The higher the vehicle speed &/or  the more direct ducting to stop spillage of the air around the core, the closer the fin pitch can be :- an offroad  buggy or hill climb car needs less fpi. than a circuit racer. Some thought has to be given to radiator cooling or you can create a problem that can limit the engine output more than the intercooler can increase it! Intercooler position, surface area, fpi., tanks & workload, all have a bearing on engine water temperature.  

                                                                                                                              

 

TANKS - the single most underrated part of an intercooler !!!

 

This tank is extremely basic & because the outlet is in line on the other tank,- even worse!

This is our tank to do the same job So much more efficient! How much more expensive?

Line up of our Hot Chilli tanks. A couple of sizes still to come. GTR type this end.

Note the over hang a tank has to have because of the construction of tube/fin

Not all cast tanks are created equal. We could get our tanks cheaper, but we pay for quality/performance.

Our cast tank walls average 3.6mm thick, negating heat soak problems assoc. with tanks that are 6 -7mm.

The areas between the lines are the "tanks" on a Denso intercooler. The large boundary layer is extremely turbulent causing a high pressure drop for no gain.

This is where allot of my knowledge comes from, hundreds of hours testing but hundreds upon hundreds more fabricating parts too test. Results do not always cross over to the real world. Alex of Bryant Engineering.

The thickness of the alloy in tanks is very important. Too thin & heat soak is negligible, but their life span maybe short due to stresses from the continual hot/cool & boost pressure cycling. too thick & they'll last forever, but suffer heat soak, which is the time it takes the tank temperature to react to ambient &/or charge temperature changes. Depending on the use of the vehicle, the effect of  heat soak varies. Constant high speed static throttle position with a front mount (road transport) is the least effected. A four wheel drive in soft sand or with a heavy boat up a ramp, fitted with a top mount, is the most effected.  We spent 14 months making sheet metal tanks for next to nothing while I looked for a good pattern maker & foundry.  It's our customers gain as our tank walls average 3.6mm thick.

Shape or Profile

Most of the charge flows through the bottom 35% of core, with the top 65% causing detrimental pressure drop  until high boost is reached. Worse again if other pipe is on the bottom too !!

The 2  corners cause large eddies & the square inlet corners small eddies which restrict flow & distribution across the core window. Worse if pipe is on bottom other end !!

Not perfect, but very good & very cost effective. Nowhere near as important to have diagonally opposite tanks like both designs on the left. Very small eddies & small  uneven distribution across core window

Square shaped/edged tanks are taboo for performance conscious enthusiasts for four reasons:-

1) They look basic, agricultural & ugly 

2) A square edge concentrates stresses along that fold (or weld), which, depending on several factors, will shorten the life of the tank to a some extent. It's surprising the number of small weeps that can go undetected for months, especially if the turbo seals are good (no oil stains), resulting in a loss of economy/performance. This usually applies more to a sheet metal tank than cast tanks, due to their thinner wall construction.

3) Most importantly is that the square edged tanks hurt air flow & increase "static" pressure drop. The intake charge does not want to make a sharp turn with the majority of the air taking a radiused path around the edge, causing some of the air to eddy back around through an elongated 360 degree tumble. This causes friction with both the wall surface & the following air, really hurting flow figures. 

4) I don't know if any manufacturers ever think of this, but when building tanks for a tube & fin core, if more air is directed to the front or back of the tubes, then that is how it stays for the entire length of that tube, as the extruded bridge walls contain that charge & it can't mix until it reaches the outlet tank, resulting in a cooling efficiency loss. With a good bar & plate core (not a cheap plain flat fin) this can't happen because the louvers or holes in the fins allow the charge to pass across the "tube" as it travels lengthways. This problem doesn't apply when the inlet pipe is inline (parallel) with the tubes & only applies a little when big boost is being used. 

 In our Hot Chilli range of tanks, the angles & radii of the triangulated roof are different for each size tank. This is not a marketing gimmick, but shows how important it is to get it right. Only three degrees sometimes made a difference of 2% of flow but 10% of window distribution.

Configuration

Two designs of tanks are very poor in distributing the intake charge evenly across the core face. Please note that 100% distribution is impossible, if the core is high enough to offer worthwhile cooling.

One design is commonly used on Rotary powered cars coming out of Sydney. The Core is 500+mm high & has the inlet/outlet pipes in the bottom of both tanks at 90 deg angle, parallel to charge flow. However the higher static pressure drop to cooling efficiency ratio, is less important to a 20+ psi. drag car (it will increase 'spool up' time! ), but decreases throttle response & a few kw. output, in a street car.  In the pictures (below) of our answer to this problem, we have designed a dual pass intercooler that splits the core area in half, so the intake charge uses the whole of the core evenly. Attention has to be paid the the sizes however, as the air speed through the core is doubled & if the charge window is too small, a pressure build up (drop) will result.                                                  

 4 of  9 tank shapes built to try to maximize distribution across the core face.

From lower down to show some entry changes made. Front 2 are absolute shockers.

In each tank we tried different baffle shapes/angles & got some mixed results. Some hopeless.

In our initial testing, 80% of charge air used end 25% of core at 264 cfm @ 25" water. Just turning bottom tank around makes a big difference 

If the outlet is below this inlet, this is the worst combination I can think of. Step causes reversion, smaller diameter speeds air flow & increasers syphoning !

This is the second worst combination I've tested & it's so popular with the Rotary set. ARE has never sold an intercooler like this - allot missed sales, but we now have a better setup.

This is our solution too cooling the Rotary. Maximum effeciency from this large core giving more cooling with less pressure drop. Relocate the oil cooler & we can make it even better. 

Here is how our intercooler looks in the car. Still fills up the front but gives more overall cooling with a little less pressure drop. There is a limit to the cfm flow through these cores & generally need to be thicker.

The other design mostly is used in the USA., where tanks are on the top & bottom of the core, causing the charge air to make two 90 deg. bends. By using a second manometer with a long thin probe, we found that 80% of the intake charge flows through the end 25% of tubes on our first test tank, which was of reasonable length. Flow rate was good but cooling rate was terrible. When we doubled the length of the tank, 55% of the intake charge flowed through the end 25% of tubes & overall flow dropped 9%, indicating that this design has too have very long tanks, but should be able to be avoided anyway. We also discovered flow 'syphoning' for the first time during this testing. The intercooler was making a strange noise, & with the aid of the second manometer probe, & then removing the tank & using the old tissue streamer on a stick trick, found that air was actually being sucked  back up the tubes next too the inlet end, by the same principal as a spray gun operation. This means that some of the already cooled intake charge was being recirculated through the core again. This creates a double loss as not only does the extra syphoned air create more pressure drop, it has already been cooled so takes away core space needed by the hot air. I didn't waste time measuring the % recirculation as we rarely use this design. Please note that this paragraph refers to intercoolers with the inlet/outlet above each other (on the same side). It is reduced noticeably if one tank is reversed, but still should be avoided if possible. A dual pass intercooler is heaps more efficient where both pipes are on the one side, but they require more height for the core. 

A few factors should be remembered with air flow. Definitely don't polish the inside of tanks or pipes. An ultra smooth surface causes capillary tension on the surface layer of air with the wall & will increase drag so increasing pressure drop.                A street car is not in high boost that much of the time (maybe 10% max.- or no licence, no tyres!), and for possibly 50% of the time in vacuum, with maybe another 30% at less than 5psi boost, so the engine operates as a naturally aspirated engine for approximately 70% of it's life. Now, how many hundreds of hours a year do the Group A Supercar teams spend on the flow bench trying to find even a half a percent increase in flow? A square edge tank can easily cause a 20 percent drop in flow, at low boost driving !! Some people confuse the result of poor tank/pipe design with turbo lag, when it actually may have little or nothing to do with the turbo's performance. This has been reinforced with our Air/Water intercooler R&D. program, where much shorter/straighter pipe lengths are used (reduced "turbo" lag). A crisper throttle response with increased "driveability" can actually be felt driving the vehicle,  very important not only on the street, but in Rally, Hillclimb, Gymkhana, Jet - boat, type competitions. In my flow bench testing, I've found that making air flow change direction by 360 deg. causes noticeably more pressure drop than a 180 deg. change.

The importance of squared tanks exponentially decreases as boost pressure increases, this is for air flow & distribution. If you see a car at the drags that runs 35 plus psi, with square tanks on it's intercooler, don't worry about it after the car has launched & is revving out, as power loss is minimal ( maybe 3%), BUT, if the engine could not spool up quickly, or needs nitrous to spool up, then the tank shape plays a very definite part in this problem, with Rotary engines seemingly affected more than 4 stroke engines. I have seen many drag cars, not being able too spool up onto the converter for 1 to 3 seconds, usually mostly in the afternoon heat - over cool night air, resulting in up to a quarter track lead to their opponent. The importance of the inlet tank shape also exponentially increases with the thickness of the core, from when it is 25% wider than the inlet pipe,  & especially for tube/fin cores.. The outlet tank only has approx. 40% influence on this as the inlet.   I have spent hundreds of hours on the flow bench with everything from conventional basic (opposition manufactureres) tanks, to some way out designs that would be laughed at, but you can't always accurately predict the results, & it's marvellous what I occasionally learn from these experiments. I reckon 85% of my r&d. time is aimed at tough street car applications to provide the most cooling with the highest horsepower output with the crispest throttle response. Note the word economy was not used, because it goes hand in hand with crisp throttle response.

 

Material

Not a pretty sight. Too thin material used.

A closer pic of the thickness guage. We use 2mm for hand hammered (formed) tanks without flat surfaces & 2.5 or 3mm on everything else.

Macro picture of 3mm sheet metal tank surface. Fold made with 10mm dia. mandrel. Can see surface cracks if made with sharp edge folder.

Surface of cast tank. Both polish up similar, but cast takes longer. Can have inclusions or blow holes that will leak if not cast proper;ly.

If the tank wall is too thick is  it will become a heat soak & counteract part of the advantage your intercooler provides. Worst example is a thick cast tank fitted to a Subaru WRX top mount - or any top mount. It is getting all the under bonnet heat (around 70c.) at low speed & then when nailed, takes a couple of seconds to drop to it's proper temperature, which isn't that cool anyway. This has much less effect on a front mount, except when reversing back after that big impressive burnout & it won't stabilize when staging either. We pay more for our cast range of tanks, but they average 3.7mm thickness & are well worth it because of the formentioned problems. 

 

Can an intercooler be too big?

 YES ! In street driven applications, an intercooler can definitely be too big, maybe not for 'attitude', but for maximum performance. It is not an argument to say that Joe Blow's RX2 runs 9.6 @ 132 with a monstrous intercooler because that car may run 9.4 @ 134 with an intercooler that is engineered very close to the overall requirements of that combination. The same may be said for Fred Nerks TX3 that runs 13.8 @ 100 with his headlight to headlight monster intercooler jumping out of the grille. The car may run 13 flat @ 110 with a properly engineered intercooler/pipe setup. This is because if a 13,500 cu. cm. core drops the intake temperature to 40 c. @ 1.5 psi. "static" pressure drop, a 9,550 cu. cm. core may drop the temperature to 41c @ 0.82 psi "static" pressure drop, & I know which will produce more power ! 

The closer to ambient temperature the intake charge gets cooled to, the exponentially larger the internal surface area of the core is needed, also exponentially increasing the friction (drag) of the charge air in the larger core, causing higher Static pressure drop. Please note that the same kw. output can be generated by two engines, but require two different intercoolers. If  one engine is fitted with a smaller than optimum turbo, then it will operate out of it's efficiency range, over revving & 'beating' the air, to a higher temperature. Even in a street application 40+ c. (eg. 120 to 160 c.) is common! This requires a more efficient cooling intercooler, with either larger volume, more cooling fins or longer tube length, than the other engine that is fitted with a larger than optimum turbo, which may only heat the charge to 105 c., placing less importance on the intercooler, but more on the inlet tank "window" (area) which needs to be larger & the tube length shorter. The first engine makes a better street driver, as the turbo will be on boost at considerably lower revs.

A really important point is that the more oversize an intercooler is, the more important tank shape is, for both pressure drop & charge distribution across the core face. Make an effort to suss out the best overall intercooler & pipework for your car, usage & driving style. It will make a worthwhile gain, & possibly at less cost! 


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. 
    --  These figures are calculated for a system with perfect air flow, without disturbance from  poor tank shape, poor core flow efficiency, gaps in pipes, no. of bends & many more factors, so the actual real world times will be slower !
    -- The actual time a molecule of air takes to travel the system during , from idle, to 8500rpm., cannot be accurately calculated as the variables are immense. These four graphs are to help you get a handle on how important it is to run a properly designed system for street throttle response & race spool up. This is part of the reason a high stall auto, turbo, 4 cyl. drag car is usually allot more consistent.
    --  Note: -- The smaller the engine capacity - or the lower the revs used - the more important the design is. 
                 -- Boost has miniscule bearing on charge air speed/time - it changes the cfm. output, making the charge denser, BUT not the air speed velocity ! 
                 -- The lights on an ANDRA Xmas start tree are 0.400 of a sec. intervals. 
    -- We have been using these figures (in house developed computer programme) for years to help us design ic. systems for customers, maybe that's why so many of our customers speak so highly of the results our products provide.
    -- Following are four PDF files to validate the above.

2.0Litre engine putting out 668cfm. @ 8500rpm.
Core size - 610x278x109mm. 2.5" & 3" pipes. Skyline GTR tanks. 26.853L.
800rpm. -1.673 secs.  8500rpm - 0.167 secs.
Exact same engine specs as above.
Core size - 500x278x109mm. 2.0" & 2.5" pipes. Evo tanks. 19.477L.
800rpm. - 1.227 secs. 8500rpm - 0.123 secs.
Exact same engine specs as above.
Core size - 150x380x109mm. 2.0" & 2.75" pipes. As our Subaru WRX top mount upgrade intercooler- not as efficient (at cooling drop) as a front mount, BUT --    800rpm. - 0.517 secs. 8500rpm - 0.052 secs.
3.1Litre engine putting out 1193cfm @ 8500-remember boost has no bearing on air speed!   All other specs exactly as the first file above.
800rpm. - 1.079 secs.  8500rpm. - 0.108 secs.

 

Pipes, Couplers and Clamps

 

 

 

 

 

 

 

 

I know they're not intercoolers, but your shiny new $1000 piece of alloy lurking behind the grille isn't much use without them. Pipes also have to be engineered or they can cause sizeable pressure drops.  The worst thing you can ask the charge air too do is turn back on itself ie. make a 180 deg turn to the right & then a 180 deg. turn to the left, like an S shape. Once air is deflected it likes to keep travelling in that direction. Asking charge air to open out at 360 degrees, as in a 50mm pipe into the middle of a 90mm flat rectangular tank,  causes a big pressure drop.   Another problem is Heat soak, especially when the throttle body faces across the tappet cover on a north/south engine or at the rear of an east west layout, making for a long pipe length from the radiator support panel to the plennum. Why is this a problem? We have measured under bonnet temps. of over 80 c. & that is not down near the turbo either. On a 26 c. day, the average charge air temp. out of our front mounts is 30 c. & this low temp. makes the charge very susceptible too heat soak from the high under bonnet temp.& naturally, the longer the pipe, the higher the rate of heat absorption. In these cases, even though we work in alloy predominately, or stainless, I recommend to do the pipe work in mild steel mandrel bends & have it HPC (or similar) thermal coated, it is worth the extra time & could be cheaper. Worst case scenario we have measured between the intercooler outlet & the plennum inlet, is 21 c. (a 25 day) on a Commodore VL with the pipe behind the radiator, with a guy in Cairns telling me he measured 26 on his Skyline R32 GTST 

When it comes time to by couplers, if at all possible, pay the extra money, buy the proper high temp. silicon ones (they look good), fit them & forget them, after you retension the clamp a week later, they do shrink under the clamp compression. I know hump hoses cause a little pressure drop, but that can be better than cracking pipes through not having enough give in the system. If there is only a short distance for the pipe, & it is between a fixed point (intercooler etc.) & the engine, use one or two humps too allow for engine movement.

Clamps are important in both sealing & longtivety of the couplers.

Intercooler Maintenance

This is the worst picture since 1997 of one of our customers horror story.

Enough too make you sick !!

Japan really must have terrible air. The black buildup actually corrodes into the alloy & must be cleaned.

This is how it should be. Back to near new efficiency, & looks the part.

An intercooler that has been in service for a couple of years (longer in rural areas), will definitely provide more cooling if it is cleaned properly. That is, soaked in a degreaser bath to remove the interior oil film that has accumulated (which may be ever so thin with a new turbo), then power flushed with water. The exterior fins should sprayed with a proper aluminium etching cleaner to remove the surface oxidation & road grime that will have formed. Both the oil film & oxidation/grime buildup provide insulating coatings that inhibit the transference of charge air heat to the ambient air. 

If not sure of the proper procedure & products to use, we strongly recommend having this done by a professional business in our field. Please see the two pictures above left, which is a 9 month old intercooler that was removed off the car for another reason, & the owner decided to do the right thing & clean it to be sure of maximum performance. He rang us & I told him we use a Degreaser, Kero & Phenol solution in our bath. He already had some degreaser at home, so bought some kero, mixed them, blocked off one end & poured the mix in to let it soak. It started to get warm after a short while, then bubble gently & get hotter. By the time he realized it was going awfully wrong & tipped it out, this was the result. It was late Friday afternoon when he rang, both of us were in a  hurry,  I didn't say & he didn't ask about different sort of degreasers and he didn't read the label which said 'not for aluminium'. It was a water  degreaser he had & mixed with the kero. The caustic base of the degreaser attacked the alloy & rendered the core completely useless, a new core being the only alternative - expensive mistake for both of us, as we helped him out with the cost. I rang a few industrial chemists & the answer was the same from them all - over the left shoulder.  For internal cleaning, only use a petroleum based degreaser, which we mix with Kero & phenol. Specific acid cleaners must be used on the external cooling fins as the average thickness is only 0.08mm - that's paper thin. Any bent over fins should be straightened  before the cleaning process, so the fin is cleaned properly & full air flow is allowed through the core. 

Check all the mounting brackets, both on the cooler & car for any signs of cracks. If you have to undo or loosen any bolts, take notice that the brackets don't 'spring' or have tension on them. If so, fix the problem so the bolts go straight in easy. This will stop any stress cracks forming or spreading.

Check all the hoses for any signs of deteriation, especially next to the clamps & in the centre of any convolutions if the hose has them. These are by far the two most common problem areas. When buying hoses, do your car a favour & pay the extra for proper high temp silicon hose. Buy it once, fit it once, & forget it (after checking clamp tension after a week). Remember that hoses shrink under compression of the clamp, so when reassembling, make sure that the clamp not only goes back in the exact same position but also around the same way, as the tabs under the worm drive mechanism are asymmetrical & could allow charge air too escape. Same with radiator hoses too. When buying clamps, always make sure the band part has a rolled edge on both sides, this stops cutting the hose with time, as they must be very tight if boost is over 10 psi. If over 20 psi. I recommend using the T-bolt clamp.

One really top, time saving trick I was given by Matt @ Chiptorque (Nerang) is to plumb an air line set at a couple psi into the inlet system & listen or feel for the leak if you're having trouble tracking it down or have doubts. A small leak is next to impossible to diagnose with the engine running sometimes. 

 

 

Repairability

 

 

This oe Nissan GTR core does not leak. Because there are no sharp creases in the damage, it will probably give several years service. 

This Skyline GTST is going for scrap. Tubes probably don't leak now, but tubes torn out of header plate & tank holed.

Close up of damage. If "will leak" tubes aren't leaking now, they soon will with hot/cool & pressure cycling

 

When considering tube construction, one thing to remember is the strength & repair ability of the cores. The weakest core by a very big margin is the plate tube & fin core. We get allot of these through our workshop (including oil coolers of the same construction), but they are relative easy to repair as they mostly crack in the centre of the end tank concertina joins.  If the crack is in the centre of the "tank" end, then it is a throw away. They have to be hydrogen brazed as the heat from TIG welding is too concentrated, usually resulting in a weep at one/both ends of the welds. Bar & plate cores are weaker than tube & fin.  The worry is that Garrett paperwork says that it is acceptable to have leaks in the core, as long as it doesn't exceed 4 psi drop from 30 psi in 15 secs !!!  We may have had a leak in a tube & fin core over the years, but no new intercooler has ever left our shop with a weep, let alone leak.  Bar & plate cores are very difficult to repair leaks anywhere on them because of the vastly differing thickness components , but tube & fin are only hard when the leak is in towards the centre of the core by more than 15mm.. The wall thickness  of an Adrad core is 1.3mm front/rear face & 0.7mm for rest of tube and K&J is 1.0mm front/ rear curve & 0.4mm sides of tube. Any competent aluminium welder will be able to weld damage to the tubes, but burning the fins away will sort out their talent !  This advice is from our workshop, that is one of the few set up too repair properly as well as fabricate new assemblies - in fact there is not another shop in Australia, set up anywhere near as comprehensive as us, for repairs !  

Chinese Intercoolers

I've tried to stay out of this as long as I could otherwise it would come over as blatant sour grapes, but there is now enough knowledge & enough people have been caught to substantiate my findings & most importantly, the rush of blood from both sides (particularly on forums) has mellowed abit. There are allot of myths, doing the forums in particular, ranging from close to right, too downright ridicules, so I will try to keep to facts.
                  1) Our intercooler sales are down near 60% to what they were 2 years ago, so they wounded our business for a while. However our intercooler dollar turnover is only down 20%, because we are making more thicker units for the higher powered cars that are being built, & our air-water sales are increasing too.
                  2) ARE can not have a core made in Australia within $90.00 of what we can SELL a complete Chinese unit for. I saw an SBS documentary on Wal Mart in USA's purchasing policies & they stated that a Chinese factory worker is paid as little as $0.78 per hour. $20.00 per hour is an average type wage in this business & what ticks me is that a whole heap of the Aust. workforce (Doctors. IT, etc.) would not even work for 100 times the Chinese wage. Lets not even mention 4 weeks annual leave with 17% loading.
                  3) 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
 
                   4) A few intercoolers have weeps, or sometimes leaks, out of the box, which makes me think that they will develop  more leaks ( maybe even if they don't have any when new) early in their life, with the rigors of hot-cold / press-ure - vacuum cycling of normal use.
                   5) Our testing & feedback from some reputable dyno shops suggest that the majority of Chinese 'coolers do a good job up to the point of being worked hard & then gains exponentially taper off. A couple of years ago, they generally had a basic fin design @ a course pitch in a small 'tube', meaning they had a low pressure drop but not good cooling efficiency, so do a good job for an engine with an efficient turbo operating in the low-middle of it's efficiency map. Try & run too much boost & they will 'choke' & pressure drop will soar.  The later trend seems to be much closer fin pitch, but still in a small 'tube', restricting flow even more, & worse still 'choke' more at a comparative lower boost. The closer fin pitch which gives better cooling rates, would only increase performance if the tube length was shorter, as the cooling efficiency quickly exponentially decreases (we have placed probes @ 100mm increments along tubes of both air-air & dry ice intercoolers) & the pressure drop (more slowly) exponentially increases along the length of a tube, meaning there is a 'sweet spot' where cooling rate & pressure drop give maximum performance. Sorry guys, but our parchment 'for big is better' philosophy & the fact that the Chinese factories don't seem to have much technical inkling of how an intercooler works, means that allot of purchases will never give near the gains possible & some, well, they're just a waste of your 'cheap money' !!!
                   6) They really have there place in the market, are very good for anyone seeking a moderate power gain with a limited budget & for more gains than this, become increasingly more difficult to gauge if they will do the work you need , all this -  is of course if you get a good one !
 

Import or 'Grey' Intercoolers

These are a much preferred option to the Truck intercoolers, talked about below, in fact, some very good units can be bought for a value price. If the unit has not been stored properly after it was removed from the vehicle (& this means in the wrecking yard in Japan, loading onto & in the container coming over here & storage over here), then it may in fact, cost you money &/or performance. They have been brought in to us for cleaning with a line of whitish powder 1/4 to 1/2 way up the core internally, from where they have been laying in the salt water coming over. Don't touch them. Sometimes, they have looked real good, but after we have soaked them in the bath & while power flushing, the amount of pebbles, dirt, & the odd self taping screw that comes out, is a real worry. Firstly, too us that we have got all the rubbish out, & secondly, that anybody buying one & fitting it straight up, has been lucky & it is clean, or else whatever is in there, will finish up in the engine sooner than later.  Paranoid? no, seen it happen too often.

If an import intercooler is for you, then look for a unit off a car that has at least 50% more power than your engine, as oe. intercoolers are sized by accountants, not engineers. Even if the engineers do get the final say, I'm sure they know how much some of you guy's will turn up the boost & so have a small intercooler to try & "choke" your gains ! 

 

Truck Intercooler Cores

There are differences between a 'truck intercooler' and an intercooler fitted into a performance car application.  However, 'truck intercoolers' is a broad term and does not sufficiently categorize the product.  Just like other types of products, truck intercoolers come in different configurations -  both bar and plate and tube and fin design. I have not seen a plate tube & fin core in a truck, they would be too weak.  However, due to their specialized application, truck intercoolers have a noticeably courser internal fin &/or external fin pitch (depending on whether tube and fin or bar and plate), than their cousins fitted into normal performance car applications. This means that although a new truck core can be used in performance applications, the core surface area/volume must be larger  in proportion to that of a standard 'performance core', & then it will give good temperature drop, but it will be at the cost of a medium/ high "static" pressure drop & higher radiator water temperatures. 

A truck intercooler core is nearly always larger because even though the engines are slow revving, they have a large swept capacity requiring a high cfm. intake charge, also there average road speed is much slower & the engine is under load most of the time. Because of the slower road speed, thinner cores per area and with less fpi., are used to keep the air speed onto the water radiator as high as possible. 37mm thick is used by truck manufacturers in there lower powered applications, but you hardly ever see them in a performance application. Trucks also have a large frontal area, giving more room for the intercooler/radiator.

We cleaned out a Volvo truck intercooler (it had plastic tanks) & during the job, discovered that it had no internal fining, turbulators, nothing, inside the charge air tubes at all. When the customer came to pick it up, I asked him how it going on his car (Cordia), & he said brilliant ! He had never measured the temperature drop, & I guess he drove pretty easy, so it may do a reasonable job, but put it on a Commodore & it would be hopeless.

The larger volume of a truck intercooler has three main drawbacks:-
1)  Higher 'static' pressure drop
2)  Increased 'turbo lag'
3)  Higher engine water/under bonnet temperatures - in front mount applications, as the large truck intercooler blocks more of the air flow through to the radiator.

Therefore, if money is a major issue than new truck cores in a performance car are a viable BUDGET alternative, especially if tanks can be made & fitted at "mates rates"! 

Used Truck Intercooler Cores

       

It is my opinion that used truck intercooler cores should not be used in a performance car.  Using a used truck intercooler core is a huge gamble, are you prepared to risk the welfare of your engine because of a cheap intercooler.  Why put a $100 core in front of a $2000+ engine? It also is a slow job to do properly, as compressed air has to be blown through the tubes, from the opposite end to which you are working on. 

Most truck intercooler cores can fit into a performance car application, but they nearly always have to be modified.  During this modification process, whether it be when the old tanks are being cut off, or when the core is being cut down in preparation for welding tanks on, or when the tanks/core is being cut down, swarf and fillings can get lodged in the core, some of which can be up to 600mm in length and can be imposable to blow or clean out.  The result is that they dislodge days or weeks later, after working their way through the intercooler tubes and intake piping and end up passing straight into the engine.  I'm sure you can imagine the result of that !? Another point is that bar & plate and finned tube cores are much, much harder to clean any solid particles out of as they get trapped in the fins & have to "travel" through the length of the tube, interestingly, the exact same reason why per sq. cm., these cores dissipate heat better, but at a higher "static" pressure drop.

Remember that a used truck core is for sale for a reason. If you buy one, hope that the truck was hit up the arse, because if it was hit around the cab, then the core was more than likely damaged or twisted to some extent. If the damaged section was cut off, your core will still have some stress & 'set' in it & even if not leaking when purchased, the heat & cutting when modifying it to fit, may release the stress, resulting in leaks in the header plate/ tube joints when finished. We do not do this work anymore for this reason, it happens far too often !

Picture of core in test tank.

Used truck cores in a performance car are a stupid, desperate alternative, & if you haven't guessed, a pet hate of mine. Use them in your smoky turboed A12 powered rusty 120Y, but please not in a performance car. I'd much rather see you buy from an opposition shop !!

Last words.

 Intercooling a forced induction intake charge is a compromise. We direct all our energies & R&D., at minimising the negative compromises & maximising the positive compromises!

A 20% gain in air flow through a component, does not give a 20% increase in power - I wish it did ! It might only result in a 0.5% (or 5%) gain in power - it all depends on the application.

If you have read this far, I thank you kindly, because it has taken me allot of work. I've tried to be as honest & unbiased as I could, so I really hope you found it both worthwhile & especially educational. Spend your money wisely, & you'll always be ahead.

 

Short Glossary (for a our full edition click here)

* "Static" pressure drop - The measurement of the drop in pressure of the air travelling through the core, friction or 'parasitic drag' measured on a flow bench (of capable capacity) at ambient temperature.

* "Dynamic" pressure drop - The measurement of the drop in pressure of the air travelling through the core, friction orO 'parasitic' drag plus the drop in pressure caused by the cooling of the intake charge (closer molecular structure of the particles resulting in a denser, smaller volume exiting) due to the mechanical design of the intercooler, or in more engineering terminology, thermal matrix heat exchanger!

 

 

 

Aluminium Radiators and Engineering Pty Ltd (ARE Cooling)
 While every effort is made to ensure details and information is correct at time of publishing Sunday, 05 August 2012
please contact ARE by phone, fax or email to confirm prices before order
.