Sprint Filter P08 F1-85 Air Filter for Racing – Suzuki GSX-R150 (2017–2020) PM250S F1-85

There are two ways to get more air through a filter: enlarge the element, or open its weave. Sprint Filter took the first route long before this medium existed — this housing holds roughly twice the filtering material other performance filters put there, and area raises flow without letting anything extra through. The P08 F1-85 takes the second route as well. Its 15,000 litres per square metre per second come from a mesh opened to 85 microns, wider than the standard P08's 80, and that half of the gain is not free: it is charged to filtration. On a faired 150 sports single there was no shortage of air to solve.

Key Features

• Dry polyester racing medium: 85 µm filtration at 15,000 l/m²/sec
• Three times the flow of the P08, bought by opening the weave from 80 to 85 microns
• Oil-free, so nothing is left upstream of the throttle body
• Drops into the standard airbox in the original's place, mapping untouched
• Kept in service with compressed air; two years of warranty from purchase
• A racing part — for a road or track-day GSX-R150 the P08 is the better buy

Area is free, mesh is not

Extra area lowers the resistance of the whole element because the same volume of air spreads across more material, and it costs nothing in retention: every square centimetre still filters as it did. Opening the mesh lowers resistance too, but only by making the openings larger — the same thing as letting more past. This element already carries the first kind of gain; the F1-85 adds the second, so a GSX-R150 owner receives air the engine cannot use and a filtration figure that moved the wrong way. The same housing feeds the capped 125s on this list, where the surplus has no taker at all.

Reading the range as a trade, not a table

The media run from the F1-85 at 85 microns and 15,000 l/m²/sec through the P08 at 80 and 5,050, the P037 at 37 and 4,500, the P14 at 14 and 1,800, down to the T12 at 7 and 560. It looks like a league table, but every step finer holds back more and flows less, and the only question is which side of the trade your riding needs. A GSX-R150 on track wants the resistance in the last session to match the first — a matter of cleaning the element, not coarsening it. The P08 is specified for road and track and is the one to buy; on dusty roads the P14 is the honest alternative.

Care and cleaning

Between outings the PM250S F1-85 needs nothing but an air line: compressed air at the clean face, carrying the dust back out of the dirty side. Nothing is re-oiled and nothing has to dry, so it goes straight back in. A full clean is lukewarm water and a mild detergent, rinsed until the water runs clear, then complete drying in open air — never with heat or a flame — before it is refitted dry. You will find the maintenance sheet in the Downloads tab.

Fitment & Compatibility

Made for the Suzuki GSX-R150, built 2017 to 2020, replacing the original in the standard airbox with no modification. The same part also fits the other small-capacity Suzukis on this housing plus one machine from another marque, five in all; the list is in the Fitment tab.