Originally Posted by
pdfbt40
As you've said, all the increased height of 5mm of the runner port is at the top. If you drop the manifold you end up with it at the bottom instead! What does that achieve in matching? It only moves the stepfrom the top to the bottom. The inserts are there to prevent over stressing the manifold with the bolts/studs/nuts and fatigue, as with any composite manifold. How do you prevent that when they are removed. The standard manifold (pre-2003) actually flows very well with mild porting, and although not necessary unless trying to exceed 180bhp, can be fitted with a larger TB easily. Is your opinion of ST170 'flow' empirical, or do you have measurements? In the short runner position it is obviously better at high revs, but thats a resonance issue, not static flow effect. Martin
well firstly I have just tried to offer up the st throttle body on my 2.0 ghia focus and although it will bolt in place its totally useless because the standard manifold only has a hole in it the same size as the std 2l throttle body. On a silver top the st170 inlet sits too high but the shape of the holes are the same. I will find my pic I took before when I can get to my own pc. I get removed collets before and then fitted washers then locktite on the bolts. It worked fine. I'm just guessing but I recon a 170 manifold will flow better than a 130 manifold considering they are both zetecs!
Last edited by 16vzetec; Apr 14, 2010 at 06:38 PM.