Sprint Filter P08 F1-85 Air Filter for Racing – Honda CBR400R (2019–2026) CM220S F1-85

An air filter is the last thing on a tuned engine that anybody notices, and usually the first thing that gets replaced. The order is wrong. On a standard Honda CBR400R the intake is not the restriction: the airbox, the throttle bodies, the exhaust and the mapping all sit ahead of the filter in the queue, and the standard element is comfortably capable of feeding a standard engine. The P08 F1-85 flows 15,000 l/m²/sec against the 5,050 of the road-going P08 — an enormous margin that a stock 399 cc twin has no way to use. It becomes a real number at the end of a development chain, not at the start of one.

Key Features

• The P08 F1-85 racing medium: 85 microns of filtration, 15,000 l/m²/sec of air flow
• Polyester run dry and never oiled, so nothing can migrate downstream onto sensors
• Twice as much filtering area, give or take, as other performance elements
• Fitting it calls for neither modification nor a remap; it replaces the standard element where it sits
• Between sessions: compressed air from the clean side, then straight back in — washed and used again
• Two years of cover, on a part built to last the life of the motorcycle

Where in the queue the filter actually sits

Restriction is cumulative, and the largest term dominates. Free up the exhaust and the intake becomes slightly more relevant; open the airbox lid and it becomes more relevant again; remap and the engine can finally act on what arrives. Only then does the difference between 5,050 and 15,000 l/m²/sec turn into something measurable, and even then it is measured on a dynamometer rather than felt through the bars. Anyone fitting the CM220S F1-85 to an otherwise standard CBR400R and expecting to notice it will be disappointed, and should be told so before buying rather than after.

What the racing medium is for instead

The honest case for this element is a bike being built rather than a bike being ridden. A CBR400R prepared for a one-make or clubman grid is asked for full throttle for twenty minutes at a time, has its intake path opened deliberately, and is serviced between sessions rather than between seasons. In that context the extra flow is usable and the coarser 85 micron aperture is an acceptable price, because the circuit is a cleaner environment than a road and the engine is inspected often. For a CBR400R that commutes, the standard P08 is the better part and the P14 is the better part again if the roads are dusty.

Care and cleaning

A wash is the deeper option and a simple one: lukewarm water with a mild detergent, rinsed until the water runs clear, then open air until the medium is dry throughout — no heat source, no flame. Most of the time it does not come to that: compressed air from the clean side, directed outwards, is all it takes. Refit the CM220S F1-85 dry; there is no oiling step at any point. The Sprint Filter maintenance sheet is in the Downloads tab.

Fitment & Compatibility

Made for the Honda CBR400R from 2019 to 2026. One CM220S F1-85 element serves six machines across the 400 and 500 twin family; the complete list is in the Fitment tab.