Sprint Filter P08 F1-85 Air Filter for Racing – Zontes ZT 350-T (2020–2026) SM277S F1-85

Nearly everything worth saying about this element is equally true of the cheaper one beside it. Both are dry polyester, both slot into the standard airbox, both are washed instead of discarded, both carry roughly twice the area of an ordinary performance filter, both are warranted for two years and specified for the life of the machine. Held up against the paper panel that came out of a ZT 350-T, the racing element looks transformative. Held up against its own sibling, it is two numbers.

Key Features

• The racing medium: 85 µm of filtration at a rated 15,000 l/m²/sec of flow
• The standard medium for the identical housing: 80 µm at 5,050 l/m²/sec — every other property shared
• Dry polyester either way, never oiled, cleaned with compressed air and refitted
• Drops into the series airbox in place of the original panel, with no modification and no remap
• Around twice the filtering surface of a comparable performance element
• Specified for the service life of the motorcycle, with two years of warranty from purchase

The two figures that actually differ

Eighty-five microns instead of eighty. Fifteen thousand litres per square metre per second instead of five thousand and fifty. That is the whole of the difference. Everything else on the specification is shared, which means every reason to like this element — its dryness, its reusability, its area, its fit, its warranty — is a reason that costs nothing extra in the standard version. So the comparison that decides the purchase is never against the disposable panel. It is against the element sharing the same housing, the same outline and the same cleaning routine.

Reading those two figures honestly

More rated flow is not more power on a road motorcycle: a slot-in element cannot give a standard ZT 350-T any, because the housing, the inlet and the calibration were signed off as one package. A weave opened by five microns is a small change too, and the manufacturer's own measurement puts the racing cloth ahead on coarse dust at 95.22 % against 93.13 %. Both differences are genuine and both are modest — which is precisely why paying a multiple for them is hard to justify on a road-registered 350, and easy to justify only where the intake runs at full demand for long stretches.

Care and cleaning

Take compressed air to the clean side and work outward through the material; ordinary dry loading leaves that way without further help. Where the surface has gone greasy, lukewarm water and a mild detergent lift it, and the rinsing goes on until nothing more comes out. Drying is by air movement at ambient temperature alone — no oven, no radiator, no flame — and the SM277S F1-85 is put back into the housing dry, exactly as the wash left it. The maintenance sheet sits in the Downloads tab of this page.

Fitment & Compatibility

The racing element for the Zontes ZT 350-T, model years 2020 to 2026. Eight further Zontes machines appear against the same code, among them the 250 of 2019 to 2021 and the 310s of 2021 to 2023.