Ive seen quite a few of these 'Swedish style' plenums, Zoo Motorsport have them for example.

Ive also heard that the original (Standard) design causes problems with airflow to no.4 cylinder....

Firstly is this right?

If so, how does the Newer style one get around this?

Is the fact (On the newer ones) that the inlet to the plenum is at the end, make a difference to airflow into each cylinder?
As surely the airflow on each cycle has further to travel to cylinder no.4 than it does for no.1, so does this affect things?

Anybody know or have an idea???

 

std gives more air to no. 3.

fluid dynamics cannot necessarily be explained, it just happens that way despite the best efforts of plenum designers.

there was a big post in the main forum going into all of this a little. the original post was by jano oddkid and titled something like "is there a better designed plenum than this". do a search and have a read mate.