I recently aquired the stock exhaust header from a Focus ST (thank you OmniFocus), and last week, went to work installing it on my 2.0 pzev. I know there has been a lot of talk as to whether or not this would deliver much performance gains. Let me settle the debate.. . yes, it does. I couldn't believe how much power I had gained when I got out on the road with it. I dont have a dyno, so no solid numbers, but performance has increased substantially at all rpm's. Most of all though at low rpm's and on hill climbs. Looking at my attached photo comparing the two manifolds, it's easy to see why.
Things you need to know if you would like to try this too:
- Haynes manuel will say you have to remove all sorts of stuff to get the stock manifold off a pzev. Even with the huge pzev manifold and an ATX (engine sits back 1" further), I was able to remove the manifold without removing any engine accessories. Only thing I unscrewed and moved out of the way was the device attached to the fuel line directly above the manifold. Getting the st manifold in was even easier. You can do this!
-You will need an exhaust gasket off of a non-pzev car. The pzev gasket has indentations allowing clean air to be injected into the exhaust stream. With the ST manifold, these indentations create exhaust leaks.
-You will now have only two of the three o2 sensors your ECU is looking for, so you will need an SCT tune, or a Steeda square port o2 cheater.
-The pzev manifold does a lot to quiet down the exhaust. I have a trubendz 2.5" flex back, and after bolting on the st header, I had to have another muffler welded in to bring the car back down to what I consider a reasonable level. The extra muffler did not hurt performance.
If anyone is considering this job and wants more photo's/info, let me know!
Very Pleased!
Things you need to know if you would like to try this too:
- Haynes manuel will say you have to remove all sorts of stuff to get the stock manifold off a pzev. Even with the huge pzev manifold and an ATX (engine sits back 1" further), I was able to remove the manifold without removing any engine accessories. Only thing I unscrewed and moved out of the way was the device attached to the fuel line directly above the manifold. Getting the st manifold in was even easier. You can do this!
-You will need an exhaust gasket off of a non-pzev car. The pzev gasket has indentations allowing clean air to be injected into the exhaust stream. With the ST manifold, these indentations create exhaust leaks.
-You will now have only two of the three o2 sensors your ECU is looking for, so you will need an SCT tune, or a Steeda square port o2 cheater.
-The pzev manifold does a lot to quiet down the exhaust. I have a trubendz 2.5" flex back, and after bolting on the st header, I had to have another muffler welded in to bring the car back down to what I consider a reasonable level. The extra muffler did not hurt performance.
If anyone is considering this job and wants more photo's/info, let me know!
Very Pleased!
