Hi all

I am running a 2.0L Zetec with a 4-2-1 exhaust manifold from a Focus ST. I have cut the manifold in-between the 4-2 and 2-1 collectors as shown in the photo:



I plan on making my own 2-1 collector that remains inside the bodywork, allowing a single down pipe to exit the bodywork in the corner between the diagonal and vertical chassis rails. Can anyone offer any advice as to how best to go about this? Do I need to ensure that the pipe lengths are identical between the 4-2 and 2-1 collector, or will it not matter if they are slightly different lengths?

Thanks
Josh

[Edited on 27/6/14 by Joshy]

I used the st170 collector. I chopped out the U bend and added a nice 90 bend on the end.

You can see it here

Ideal world same lengths, real world a bit of difference will not hurt as these cars are to small for optimum exhaust lengths anyway.

I made mine, get the two pipes to but together, cut some wedges to make the profile a long oval, now grab the pipe that they both feed into and cut a piece the length you want the collector to be. Split this in two length ways leave 1/4 still joined at the end and pull open into a V so the it neatly fits over the two pipes and tack in place on the out side edge, now trim this end so it's a neat fit at both ends and weld on.

Using a bit of spare pipe, open up and hammer flat, now cut a couple of V's to infill then trim the end and weld on you exhaust pipe.

You can see what I finished with here


Exhaust top view , just needed cleaning with a grinder and polishing.