Fuel rails: Parallel or Series?
 

What's the thinking on parallel v series fuel rails? If parallel do the fuel hoses need to be the same length? Is there a 'cheap' way to go parallel using the existing rails?

Parallel is the way to go as the OE setup is in series, which causes the potential for cylinder 3 to run lean. I fitted a parallel kit a few years ago, not sure if it is possible to re-jig the flexi pipes so it becomes a parallel system.

Yes it is possible, but realistically manifold has to come off to do it.

Also the angle of the fuel in on the passenger side is wrong for decent hose-running (imo) and on the drivers side the fuel in pipe is under the manifold itself.

Ie is not pretty, but works. I've lopped off the fuel feed on the drivers side and rewelded it so that it is accessible and pointing in the right direction.


You also need an aftermarket fpr of course.

I know the perceived wisdom is that the parallel option is better than the series set up but it begs the questions: why did Subaru not go parallel from the off, and is a typically complicated parallel system better than the series? The parallel set ups I've seen appear to have hoses in less than ideal positions.