PIR (Panel Impact Ratio) is the simplest way to dial in the perfect snow foam mix for your setup. Here’s how it works – and why it matters.

What exactly is PIR?
If you’ve been using snow foam for a while, you’ve probably come across PIR – Panel Impact Ratio. It sounds a bit technical at first, but it’s actually a super useful way to figure out how strong your foam mix really is when it hits the paint. Once you’ve tested it, it’s easy to dial in perfect results every time.

The quick and easy test
We usually start by filling the foam lance bottle with exactly 1 litre of water. Adding a few drops of food colouring can make it easier to see, especially when spraying into a bucket. With the mix dial turned up to max, the setup is connected and sprayed until the bottle is completely empty.

Measuring the results
Next, we measure how much liquid ends up in the bucket. That number is called the Total Volume Output (TVO). Let’s say the output is around 4300 ml – though this will vary depending on the equipment used.

Making the calculation
To figure out how much product to use, we divide the TVO by 100. So with 4300 ml, we get 43. That’s how much 1% PIR equals. If we want a 6% mix, we multiply 43 × 6 = 258 ml of product. The rest is topped up with water to reach 1 litre total in the lance.

Why we trust PIR
Before using PIR, foam mixes could be hit or miss – too weak one time, too thick the next. Now, we get consistent results every time, with no wasted product. It’s a one-time test that makes a big difference in the long run.