Simons Flexible Pipes

Simons keeps its flexible pipes simple: stainless steel sections listed by diameter and length, from Ø 38 mm to Ø 89 mm and from 100 to 250 mm long. The common road sizes of 45, 51, 57, 64 and 76 mm each come in more than one length, so you can pick the shortest section that bridges the gap in your system.

Alongside them is a mild steel compensator in 50.8 mm, or 2 inches, for systems built in mild steel.

On most front-engined cars the flex joint belongs in the front pipe, just behind the manifold or downpipe, because that is where the engine’s movement on its mounts reaches the exhaust. Taking the movement out there protects the joints, hangers and silencers further back.

Size the section to the outside diameter of the pipes, and fit it straight, with the ends aligned before welding, since a flexible pipe forced into a bend wears quickly. Welding stainless to a mild steel system is possible with a suitable filler rod, but a stainless section on a mild steel exhaust will outlast the pipes on either side of it.