SRM Exhaust Manifold Flow Test

Product:

Silly Rabbit Motorsport Audi B5 S4 exhaust manifolds

Specifications:

silly rabbit motorsport exhaust manifold inlet diameter
Inlet diameter at mounting surface
silly rabbit motorsport exhaust manifold primary inlet
Inlet diameter inside primary
silly rabbit motorsport exhaust manifold outlet
Outlet diameter

Product Pictures:

silly rabbit motorsport exhaust manifold inlets silly rabbit motorsport exhaust manifold primariesTest:

The Silly Rabbit Motorsport exhaust manifolds were attached to an adapter that simulates the B5 S4 cylinder head exhaust port in diameter.  The adapter is affixed to a flow bench that is operating in exhaust mode and the pressure drop and airflow through each primary runner is measured with the air exiting at the exhaust manifold outlet.

silly rabbit motorsport exhaust manifold mounted on flowbench
Silly Rabbit Motorsport Exhaust Manifold mounted to flow bench

Results:

silly rabbit motorsport exhaust manifold flow bench test results

Comments:

I was a little surprised by how much additional airflow the Silly Rabbit Motorsport manifolds allowed in comparison to the AWE exhaust manifolds.  Before putting the SRM product on the bench I looked the part over and made a guess as to they would perform comparatively.  I’d guessed that they would flow a little better, not the 20-30% more than the AWE product that they ended up doing.

Follow up

An additional test using a velocity probe to determine the exhaust manifold outlet airflow velocity was conducted.

Audi B5 S4