The ability, or lack thereof, to control temperatures in your engine bay can not only rob power if your intake charge is too hot; if your lubricating fluids or engine coolant temps are not kept in check, very bad things also can and will happen.

To combat this by simply increasing the cooling capacity is not always an option; nor should it be the first thing you jump to doing, as fabrication and part replacement are costly exercises. Your first port of call should always be to maximize the efficiency of your current coolers. While proper ducting before and after is a must, there is a product on the market that can help increase the surface area by 50 percent, and it’s in an aerosol can. Yip, you heard us right — you basically spray and walk away. 

How it works

TSD’s Boron Nitride Thermal Coating can be applied to the surface of any cooler, and even on driveline components like gearboxes to increase their heat-dissipation efficiency. How it works is relatively simple — if you are are a chemistry wizard. The active ingredient, ‘boron nitride’, is a synthetic compound of boron and nitrogen, and can be synthesized in hexagonal and cubic forms — much like its neighbour on the periodic table, carbon, which forms graphite or diamonds. In its hexagonal synthesized form, boron nitride is also known as ‘white graphite’, due to its crystallized lattice structure. It’s this complex structure that effectively increases the surface area of any surface that it’s applied to. In very basic terms, the more surface area you can create, the larger the contact patch with air flowing past the surface, so more heat can be transferred from the part to that passing air. The coating itself has a thermal conductivity 20 times that of 5025 aluminium. 

How to apply it

It’s a relatively easy product to apply and can be used on basically any material — steel, stainless, aluminium, brass, copper, plastic, or composite. However, the majority of surfaces you’ll use it on in automotive applications will be made of aluminium.
As when applying any other coating, you’ll need to ensure that the surface is clean of any contaminants using a wax and grease remover. On the cooler we applied it to, we used a Scotch-Brite pad and wax and grease remover on the end tanks, and simply wiped the tubes carefully. Then, just spray on in light coats, ensuring you don’t apply it too thick, as it will run. Allow 15 minutes between coats, and apply three or four coats to achieve a decent film build-up. We did four on our cooler. Once you’re happy, allow another 15 minutes at least before refitting the part to the vehicle.

For more information about TSD's Boron Nitride Thermal Coating, head to

René Vermeer

Dutch, French, or just a Kiwi, René isn’t quite sure, but he does know he has a passion for Japanese vehicles like no other. A well-seasoned Gran Turismo player dating back to his single-digit days, René has a comprehensive knowledge of a wide range of performance vehicles and has owned more than 30 performance cars here in New Zealand, ranging from Nissans to Hondas. A lover of photography, you’ll find him either peeping under someone’s bonnet to snap a detailed shot, or on the side of the racetrack, perfecting his panning.