FRP/Wiseco E85 & Race Gas Pistons

FRP Engineering's E85 and Race Gas pistons for Audi AAN and 3B inline-five engines were developed in partnership with Wiseco and proven in our land-speed-record-holding S4 sedan.

These are the first flow- and compression-optimized racing pistons for these engines, featuring true 3D dome milling and Aero Humps that interact with the intake valves during overlap to improve cylinder filling and scavenging of exhaust gases.

With 6 cc positive dome volume, they are intended for ported combustion chambers where bore matching and flow relieving around the valves yield chamber volumes of 48–51 cc. In 86.4 mm stroke engines with a 50 cc chamber and .062" MLS gasket, they produce 10.1:1 compression; with a 92.8 mm stroke, 10.65:1 with similar specs.

These compression ratios are ideal when tuning to fully exploit high octane, slow-burning race gas or E85–E98 fuels with their lower caloric content and high latent heat cooling.

Key Features

• • Valve pockets sized for oversize valves and high-lift cams
• • Optimized quench pad height
• • Optional ceramic dome and low-friction skirt coatings
• • Custom compression heights available to suit builder preference
• • Strutted 2618 alloy forging using a short, stiff 1.195" long, 0.225" wall pin for ring-band support at high boost levels

Custom C350 DLC-coated pins are available on request. Bore sizes 82, 82.5, and 83 mm; standard ring pack is 1.0 / 1.2 / 2.8 mm.

Custom ring specifications and lateral gas ports in the top ring groove are available. Piston and pin assemblies are rated to 250 hp per cylinder and come complete with rings, pins, and clips.