S3 E-Type

Air Injection Removal

by Dave Lacey

There are many reasons why you may want to remove the air-injection system from your V12, not least of which is that it's probably not working properly! The air pumps become ineffective, the check valve fails and the injection tubes get blocked with carbon.

Removing the system saves a little weight & liberates a little power (because you dont have to turn the pump), it also creates space that you can use for a modern alternator upgrade and enables the use of Lambda sensors in the exhaust and 'cleans up' the top of the engine allowing easier access to other components.

To do it is quite simply an unbolting job for the pump & plumbing, the only question is how to block the holes in the manifolds. I asked a local engineering shop to copy the general design of the 'foot' on the original air injection pipe, but make the short protrusion solid to block the airway:

These are then fitted with "O" rings and held in place by the inlet manifold bolts/studs, just like the air injection pipes were before.


Overall I think it's a straightforward job that simplifies the future maintenance of the engine a little.
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