Spark Exhaust Bent Tube 90° Ø 70 × 1.2 mm Stainless Steel Universal G9158

Seventy millimetres at ninety degrees, in a wall a fifth thicker than the sizes below. A right angle at a diameter where most workshops stop trying.

Key Features

• Mandrel-formed 90° bend, AISI 304 stainless steel.
• Ø 70 mm outside, 1.2 mm wall thickness.
• Thicker wall than the 32 to 60 mm bends.
• Matches Spark's 70 mm straight tube, article G9009.
• Spark part number G9158, made in Mantova, Italy.

A Corner in a Chamber

At seventy millimetres a right angle is not routing gas — it is turning a volume. Pre-silencer boxes, expansion chambers and the large sections of a custom system sometimes have to change direction around a subframe or a shock tower, and there is no way of doing it in less space.

The Hardest Thing in the Range to Form

Large diameter, thin wall, maximum angle. Every factor that makes a tube collapse under a bender is at its worst here, which is why a formed ninety at seventy millimetres is a specialist part rather than something a fabricator produces on the day.

The failure mode is a folded inner heel: the material buckles instead of stretching, the bore is permanently reduced at the turn, and nothing recovers it.

Card Before Cash

With the tangents counted, this bend occupies a cube roughly two hundred millimetres on a side. Cut the outline from stiff card and hold it in place before ordering — on a part this size a drawing is not a substitute for the real footprint.

Fitting to a Flat Face

A box built around this diameter usually meets a plate somewhere: a bulkhead, a mounting face, an end cap. Cutting a large tube to sit square on a flat is a template job rather than an eye job — wrap paper, mark, cut, and check the fit dry before any heat.

Shipping Damage

A large thin bend is the article most likely to arrive dented. Check both tangents with a vernier across two axes when it comes out of the box, before anything is cut — a part that is out of round on arrival is returnable, and worthless once it has been shortened.

Ordering

One bend per article. Spark builds 30°, 45° and 90° at this diameter.