[ErnessW]

I've recently had to remove two Focuss engines, one bad one (junk) and one very used one (still running), they are both Split Port (valve seat droppers).
The incredible amount of air ducting and manifold size, right from the front of the grill, under the battery to the air-filtre, then across to the top of the intake manifold and multi-channel piping of the intake manifold, lead me to examine what is really neccessary back in there to have the engine run.
So, close examination of the mini-manifold between the big piping and the engine, revealed a secondary set of four flaps like you'd find in a lawn mower engine. I guess these flaps open to let more air in when you tromp on the gas pedal.
So, seems to me you could completely remove everything from the grill back to this mini-manifold, plug the right half of the open split ports and connect the gas pedal linkage to the four flaps and you'd have a running motor minus a ton of intake junk. (no air filter).
;-)

[hardk0re]

those are intake manifold flaps, they control the runner length for high rpm/low rpm power bands. You won't be able to use those as throttle controls.

That said there are lots of people that have put a custom intake manifold on the cars, but honestly unless your boosted they will bog under high rpm or low rpm conditions depending on which runner length you choose.

[ErnessW]

What do you mean by "bog". There's nothing pulling the air along from the air filtre to the cylinders but the vacuum created by the pistons themselves. Seems to me, the less air volume, (the roughly six feet of pipe length from grill to injectors) the easier the air will be sucked into the cyclinder when the valve opens.
I have a picture somewhere (I'll find it) of the four flaps that comprise just three inches of intake manifold for a working adjustable air intake already existing on the sp engine.
here's one of that extra big intake manifold stuck on the side of motor.

[ErnessW]

Also, as an aside to this post, where is the fifth injector? I thought there would be a fifth one for cold starting. Is it in this picture and I'm missing it?

[hardk0re]

Since your looking at the first gem's.. Pickup "high performance ford focus builders handbook", it may explain some things for you. The IMRC is by no means a throttle body it changes the length of the intake runners for different resonances to achieve better power. Unless your forced induction a real short intake runner will not net you more power...this topic is in fact covered in this book along with some dyno results to back this up.

regardless of anything your going to need total custom tuning if you start messing with throttle bodies per cylinder, or custom intake manifold.

There is no 5th injector...... unless your redneck tuning your car...

[GFXjamie]

Don't forget your mass air sensor either...

Either way leave the air box. Snorkel can be removed but is pointless. If you want to upgrade swap in a Zetec next round with a mtx75 and get another 20hp and be able to mod if more is wanted