Project Toyota Supra MKIV: Part 7 – Choosing the right intercooler


We couldn’t resist, and hunted down an eBay core to show you here.  Notice the fins having a straight-through tunnel-like flow with no louvers.  This wil most likely provide minimal cooling, especially to the rear of the core.

It just so happens that the previous core this car was rocking had “/” type fins, and were louvered instead of staggered (which is why you can see through this one, too), to break the airflow up.

The 4-in core we got is the narrowest ETS offers for the Supra.  If you need bigger, they offer 5- and even 6-in cores, and the latter is good for a reported 84% efficiency rating at a whopping 1500hp!

Thicker cores are always tempting, but you have to keep in mind that there will be some ambient flow sacrificed to the cooling components, as well as increased turbo lag.  That’s why you’ll see these cores on more dedicated racecars.  There’s always a compromise.


The end tanks are also important when it comes to flow.  I’ve noticed ETS’ cores are slightly narrower with larger end tanks to help distribute the charge flow through the top and bottom rows more evenly (and similar to a large intake manifold evening out the flow to the intake valves, like our Hypertune).

When comparing this core to the car’s previous Spearco core, which measured 28-in long by 10.5-in high, a little sacrifice in core width and, thus, surface area, seemed to be okay when we’ve got large end tanks to distribute the air more evenly from top to bottom.  However, in our case, and by comparison to the Spearco, the ETS’ surface area is only compromised by a mere 2% because the ETS core is also taller by 1.5-in.

In terms of performance, assuming the same surface area, a greater core height is more beneficial than width because the rule of thumb is—with all other things being equal—the shorter the core, the less the internal pressure drop.  Also, as mentioned earlier, we have the potential for greater cooling because we have more rows.  We have four more, to be exact (19 vs 15).

The only downside to going taller in the Supra's case is that the coolant overflow tank has to be relocated.  Thankfully the ETS intercooler upgrade kit includes a relocation tank.

If you look closely, you can see that ETS goes the extra mile by hand-polishing the inside of the tanks to avoid air turbulence.  The tanks are also reportedly welded on the inside and out, and pressure-checked to 40 PSI.  For cars pushing greater boost, ETS builds their end tanks out of thicker material and adds a cross brace to ensure maximum performance and durability.

ETS end tanks are also triangulated, which cuts down on the welds and ensures maximum durability.  The firm stands by their work to the extent that they provide a lifetime guarantee on their intercoolers to the original purchaser.


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