Right, I'm bored shitless sitting in sainsbury's car park waiting for the mrs!
And I was just trying to work out why the 500 plenum is supposedly able to support 600bhp+ and a 4x4 430bhp ish?
Before stating the obvious of 8 injectors ie. More fuel, I was thinking more along the lines of restrictive properties, I was also trying to find a thread where I read that the 4x4 was good for near 600bhp.
Is there that much difference in size/volume or is there a massive difference in the elbow?
Also heard people say that the flutes/trumpets are more the restriction rather than the plenum it's self!

Any thoughts or proven facts?