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TriFoam™ filters: three is the magic number


Every single one of our intakes and filters uses the same hand-built TriFoam™ filter material. But why?

Maybe we should start with the question of what your air filter needs to do.

Well, it’s pretty obvious that your engine should only be fed lovely clean air to keep all those minute debris and dirt particles out of its critical inner workings.

Not that anyone would recommend doing so, but if you did try running without an air filter for even a few hundred miles, small dirt particles in the air will very quickly cause premature engine and turbo wear - which in turn will lead to loss in performance and eventually engine failure. Just imagine those tiny grit particles hitting your turbo’s blades, and grinding against every little component in your engine. Not nice.

So, that much is clear: a filter needs to filter microscopic dirt out of the airflow. But of course that’s only half the story, especially when we come to high-flow performance intakes.

The most effective filter in the world will also be terribly restrictive in airflow terms. It will simply not allow enough air to flow into the engine to make power. Yet the lowest power restriction is simply an open intake pipe with no restriction, but giving zero filtration.

So as with everything in life, it’s all about finding the perfect compromise.

We need to discover that filter material and design that enables minimum pressure differentials, yet gives maximum filtration protection to your engine.

Our engineers like to apply a bit of science to this - on all of our intake development we use pressure transducers to measure (plus model in CFD) this pressure differential to assess the restriction of each design. They dream of achieving as close to the impossible 1:1 pressure ratio as they can (ie, no pressure drop at all).


Which is how we have arrived at our TriFoam™ material - used for every single intake product we offer. Because, compared to paper, cotton or other filter technologies, this reticulated polyester foam achieves optimum performance against our three key criteria:

  • Maximum Air Flow: the ability to allow air to pass through without causing a large drop in pressure.

  • Cleaning Efficiency: the capability to arrest a high proportion of airborne dust while feeding the engine clean air.

  • Dust Load-up Tolerance: the capability to absorb a large amount of dust over long-term use without reducing air flow capacity.

With our unique TriFoam™ System, we can sandwich three layers of different thicknesses of finer or coarser foams, precisely tailored for our different applications:

1. Thinnest but strongest structure

The thinnest possible wire mesh structure - the thinner the elements, the less the restriction.

2. Coarse outer layer

Stops large pieces of dirt and foreign matter from penetrating further. Straightens air flow into sub sequent layers.

3. Medium grade mid layer

Serious filtration layer traps most of the harmful dirt that leads to engine failure

4. Fine inner layer

Extracts all the fine particles but still allows full air flow to the engine for maximum power.


Compared to other materials, our TriFoam™ filters offer many additional advantages, including a significant reduction in noise while providing more power for longer.

What's more, because we use the very latest adhesive technologies to bond the foam layers, TriFoam™ filter assemblies are resistant to water, fumes, oils and fuels - including the exotic brews used in racing.

Each one of our filters are each hand-made in the UK, alongside F1, WEC and Touring Car filters. Is there any better proof of our filter technology than that?



The most important factor in our choice of TriFoam™ is the exceptional dust-loading characteristics. We know it doesn’t sound terribly exciting. But this really is important to your car’s long term performance.

Here’s the interesting thing. The three most common filter element materials – cotton, paper and foam – all perform pretty similarly when brand new out of the packet.

And guess what: when manufacturers of cotton and paper element filters show flow bench or dyno test results, they’re using brand new, clean filters. And, yes, they show good flow rates.

But take a look at our testing results above. The really significant thing here is how rapidly the paper filter and even more noticeably the cotton filters become restrictive as they load up with dust particles.

The cotton elements are great for airflow, but only for a short time.

Which was just fine for their original application on pure racing engines, where airflow was vital and ultimate engine life was of little concern. And of course, when a new filter was fitted after every race.

But when it comes to a real-life benefits on a road car, changing filter elements every few months isn't realistic.

We’ve tested our TriFoam™ filters after many miles of use, and the power drop is minimal, even when very dirty. Try the same thing with cotton or paper, and you may just be shocked.

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