Eventuri Honda FL5 Turbo Tube

Some photos show our optional engine cover and intake.

Introducing our Carbon Turbo Tube for the Honda FL5, which is a direct replacement for the OEM metal turbo tube. Utilising the same design brief as our FK8 tube, we developed the FL5 version with these 3 key objectives:

1) VOLUME : Inlet Diameters – Eventuri 78mm at the intake end, increasing to 88mm. In comparison, the OEM tube starts at 76.5mm and then stays at this diameter before reducing to the turbo inlet. This equates to an increase in cross sectional area of over 32% at the largest point. Although the OEM FL5 tube doesn’t pose a restriction to the turbo at stock boost levels, we expect our larger tube to benefit at higher boost levels where the airflow demand is increased.

2) FLOW QUALITY : Having just a large internal volume is no good unless the flow path also allows for smooth airflow to the turbo. By using high temperature Prepreg Carbon Fiber we have managed to achieve a smooth internal surface. In contrast, the stock inlet tube is made from cast aluminium which ends up with a rough internal surface. This coupled with the smooth curvature of the elbow results in a flow path which minimises turbulence.

3) TEMPERATURE : The final criteria was to minimise the conduction of heat into the airflow. The stock inlet is directly connected to the turbo and so immediately conducts heat as the turbo spools. Our system uses a machined flange which connects to the turbo and then a silicon coupler with an integrated thermal spacer to keep the carbon elbow from having direct contact with the turbo. This barrier coupled with the low through-thickness thermal conductivity of carbon fiber results in less heat being transferred to the airflow.