Goopy Performance Apex Seals

We recommend 0.0381mm of clearance between the apex seal and the rotor slot for all applications, boosted or naturally aspirated.

3 mm 12A or 13B Goopy Apex Seals are 2.921mm thick, and you should be able to slide a 0.0381mm feeler gauge into the rotor apex slot with a new apex seal.

Our oversized 12A 3 mm seals measure 2.9972mm (+ / - 0.0254mm). If your rotor slot measures 0.4572mm - 0.508mm, you may benefit from our oversized 2 mm seals which will allow you to re-gain the 0.0381mm suggested clearance.

Our 2 mm apex seals are 1.905mm thick and you should be able to slide a 0.0254mm feeler gauge into the rotor apex slot with a new apex seal in place.

Goopy Performance 13B 2 mm oversized apex seals measure 1.9812mm (+/- 0.0254mm). If your rotor slot measures 1.9558mm - 1.9812mm, then you may benefit from our oversized 2 mm seals which will allow you to re-gain the 0.0381mm suggested clearance.

If your gap with the seal in place measures 0.0508mm - 0.127mm it is still usable, but keep in mind that tighter clearances means greater sealing characteristics.

Take note that 12A and 13B 3 mm apex seal slots suffer the most when it comes to rotor slots over-tolerance. We have measured many used rotor slots and have found very few that still had the stock widths.