Install – OEM ST exhaust

Yesterday the STedan was back at Zero Limit for a never-before-attempted project. As seen in the last post, Mario replaced his factory exhaust system with an aftermarket assembly; that meant that there was an OEM ST exhaust left over. Light bulbs lit up.

With my Focus being built with the idea of an ST sedan in mind, fitting an ST exhaust would be a great way to continue the progress and further set the car apart from other Mk3s.

Currently only two MK3s are known to have had ST exhausts fitted, but both are hatches. With mine being a sedan we knew there would be some additional work involved. Jackie was up to the task, Mario was willing to provide the exhaust, and I knew that it would work perfectly with what I have in mind for down the road.

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Yesterday morning I arrived at the shop and the Focus went on the hoist right away.

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The ST system was held up underneath the car to confirm what would fit and what would need work. The sedans are nearly 7″ longer than the hatches so an extension had to be added to the exhaust. It had to go in above the rear subframe; apart from that the exhaust fit right in the opening left by the stock system.

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The original exhaust in all its glory. 2″ piping all the way with a giant muffler mounted at the back. Less than two years old and looking…less than perfect. Note the rust appearing on the new sway bar and other components…I wish I didn’t have to winter drive this.

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This is the front half of the ST exhaust. The piping is 2.5″ and there’s one less resonator. While this obviously isn’t new, Mario’s ST is much younger than my SE and hasn’t seen a full winter yet.

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The whole of the ST exhaust, with the special muffler and centered tips in the background. Alternatively just an axle-back conversion could be done but why stop there? We were going for a full replacement.

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With parts gathered and the initial checking and testing done, we committed to the project when Jackie cut the original exhaust and it was removed from the car. You have served me well, but it was time to make some progress.

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“Okay, we’re really doing this.”

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I had asked one owner I know who had done the install before and he said it was fairly straight-forward. The first half was temporarily bolted in place and then we noticed the first issue; the mounting flange is not at the same angle relative to the exhaust as it is for the N/A system. As a result, the ST piping sat angled under the car. No good. The flange had to be rotated.

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Here you can see sections of new pipe where the exhaust was cut, holding it all in line, allowing for adjustment of the pieces. Jackie’s patience here was invaluable. Many times he had to go back and cut off a fraction of an inch or rotate the piping again to get things lining up properly. We both admitted to expecting to be done by lunch, but at that point we were just getting started.

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The muffler was mounted so that we could get an idea of what it’d look like. I texted a picture to Mario and he was really excited to see it. Haha.

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Later in the afternoon the pieces of the puzzle were starting to fall into place. The muffler is still crooked here as it was aligned last. That alone was a bit of a challenge but it had to be right or it would be very noticeable.

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At this point Mario arrived to check on the progress in person.

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That was when the picture-taking slowed as it kept getting later in the afternoon and the Beyond meet was approaching, which I was planning and hoping to ‘reveal’ it at. After a bit of welding, final alignment and tightening of bolts, it was in! With everything ready to go I backed the car out of the shop and parked it next to Mario. Two days, two Foci, two exhausts.

I was nervous and excited for the first post-install start up because I had no idea what to expect in terms of sound. When I turned the key, the result was a nice deep tone and just what I was hoping for.

I can’t thank Jackie enough for this. Overall the install – in concept – is pretty simple. Rotate the flange, lengthen the system slightly, and put it all together. In reality though, there were many small tweaks to make and Jackie kept making them. I tried to help out where I could (mostly holding things when needed…) but Jackie was the one with the experience and tools to make this work.

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“Mustard and ketchup.” – Mario

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ST exhaust installed

I kept teasing this and some people started making guesses as to what we were working on. When I arrived at the meet they then started coming over to the car to see if they were right. I think everyone who did guess was correct, in fact.

With that done, now I’m driving the Focus around and seeing how the exhaust sounds under varying conditions – hills, flat roads, idle, acceleration – so far so good. It’s civilized but at the same time you can tell there’s something different. The Focus has a little more bark and bite.

I hope to be able to get this car on a dyno someday to see just what the intake and exhaust have done for the power. Until then, there’s the soundtrack to enjoy.


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