There is no OE manifold that you can use on the zetec that bolts straight on, so I can see why people use specialist items.

I think the coments used against Simons manifolds are harsh, what's the justification for it being a poor item? 13.1 is dam good in an Escort, how many are faster? Power output would be a better way to gauge a manifold imo.

Most Zetec engine's i've seen aren't really making big power when compared to other forced 16V 2l's. At 350-400hp, I don't think the inlet is being pushed so power differences between them are going to be small. We all know flowbench figures are of limited value when it comes to predecting the dynamic charcteristics of an internal combustion engine. Until somone straps them all to the same 500bhp+ engine on a dyno it's all speculation.