Sprint Filter P08 F1-85 Air Filter for Racing – QJ Motor SRK 800 RR (2025–2026) SM266S F1-85

Nothing on this page will be noticeable from the saddle, and it is better to open with that than to bury it. The racing weave is rated at 15,000 l/m²/sec where the standard panel for the same airbox is rated at 5,050, and it is listed at a little under twice the price of that panel — yet no measurement has ever been published for an SRK 800 RR running one, and rated throughput is not something a rider perceives directly. Two positions follow. The honest one is that this is the most open medium Sprint Filter makes, bought on its specification and kept working by maintenance. The other is a power claim, and it is not made here.

Key Features

• Racing specification: 85-micron dry woven polyester rated at 15,000 l/m²/sec
• Close to three times the rated throughput of the standard weave for this airbox
• 95.22 % retention on 100-micron particles, measured against 93.13 % for the P08
• Goes into the unmodified series airbox of the SRK 800 RR; no recalibration
• Around double the filtering surface of a conventional performance element
• Dry from new, never oiled, cleaned with air; two-year warranty

Bought on specification

By Sprint Filter’s own account this is the air filter most used in MotoGP, Moto3, World Superbike, Supersport and Superstock. That is a manufacturer describing its own product, and it describes where the cloth is at home rather than what it will do for a road-registered SRK 800 RR. The specification itself is public and unambiguous: the widest aperture in the range at 85 microns, the highest flow at 15,000, and a measured retention that beats the standard weave on 100-micron particles while passing more of everything smaller. Bought for those figures it is exactly what it says. Bought for a power gain it will disappoint, because a drop-in element does not make a standard SRK 800 RR noticeably stronger.

What keeps it working

Attention, mostly. The most open cloth in the catalogue is the one that most rewards a properly seated seal and a lid closing on an undamaged edge, since air that travels around a filter is not filtered at all. It also suits an owner who cleans to a schedule rather than on the evidence of a glance. None of that is demanding, but all of it is the difference between a racing specification working as intended and a coarse weave doing less than the standard one would have done.

Care and cleaning

Compressed air on the clean face restores it between outings, which is how this medium is meant to be maintained. Oily residue lifts under hand-warm water with a small amount of mild detergent and a full rinse afterwards. Everything dries in ambient air and nowhere near a heat source, since heat, not dirt, is what finishes polyester. The SM266S F1-85 is refitted dry and untreated, and the maintenance sheet for it can be found under the Downloads tab on this page.

Fitment & Compatibility

Made for the airbox of the QJ Motor SRK 800 RR, model years 2025 and 2026, one element per machine. This part number covers that model only; the fitment list on this page confirms it.