Shift Change – Automatic Transmission Cooler R&D, Part 2 – Production Sample and Testing


It’s old news now that the Supra has returned. Back in late 2018, it didn’t seem like there could be anything hotter in automotive news media. The Supra returned. What else, mattered? Plenty more mattered, as it turns out, as the heat has since blown over on this subject, and the Supra’s are quite literally generating their own heat out on the roads and tracks. As we covered in the first post, heat in your automatic transmission is fine, but too much heat is not good. Luckily, we’ve already devised a solution to keep the Supra shifting at the right temperature.

We already gave you a preview of our design, but it’s finally here in the flesh at our R&D facility. Since we didn’t go into too many specifics about the new design, let’s dive in with our production sample to go over our enhancements, starting with the core.

If it wasn’t already obvious, there was quite a growth spurt with our core. Our design adds just about an inch to each side, measuring in at 20 x 6.7 x 1.4″ with a volume of 187.6 cubic inches. As compared to the stock unit, we were able to increase the volume by 162% with a whopping 412% bump in external fin surface area, all steps in the right direction when it comes to improving heat dissipation. To take it a step further, we also included internal fins on our core. These fins are built into the fluid tubes and work essentially as a conduit for the heat to travel more effectively to the exterior fins, resulting in an improved heat transfer.

With the core size out of the way, let’s talk about construction. Really, in this case, there isn’t much to say on that topic since we opted for keeping with a tube-and-fin layout. It’s the more lightweight option that we have, not to mention that we’re already dramatically improving on the cooler’s performance with the size increase. Sure, a full-on, heavy-duty bar-and-plate core would only further increase this heat exchanger’s cooling potential. Still, given our current improvements, it would essentially be overkill for this application. Remember what I said in the last post about overdoing it? Bar-and-plate would be overdoing it.

When it comes to the end tanks, we decided to follow a similar design to the stock cooler, including the mounting tabs and inlets. This will allow for a simple install and integration on your Supra.

These improvements look great on paper, but how does it stack up against the stock unit? To find out, we performed a laboratory-style bench test between the two cores to gather a more precise comparison. Each core is fixed to our dyno fan with the same amount of air moving through them. From there, automatic transmission fluid is heated to 206°F before pumping through the core with the inlet/outlet temperatures, and fluid pressure is monitored for 8 minutes. From our testing, we found a much more efficient dissipation of heat with minimal pressure drop.

With the advancement in automatic transmission technology, it’s becoming less of a slight on the enthusiast when companies abandon the manuals altogether. Don’t get me wrong, it’s still a tragic loss, but we’re finding means to cope. In either case, these powerful automatics still need to keep their cool. The BMW cooler is no slouch, but with more demand requires more cooling power. Make sure you get your upgraded cooler today.


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