FAQs : Power Upgrades Ford Fiesta ST150 / Fiesta XR4

FAQs relating to our performance exhaust manifold, unichip, Stage 1 Kit and camshafts for the Fiesta ST150 / XR4.

1.  I am interested in the Stage 1 performance kit or 4-2-1 manifold for my Ford Fiesta XR4. Would I need to buy any extras to go with the kit?
You will need nothing else. The header can be fitted at any local exhaust shop near you. It is very easy to fit. The SWR mapped Unichip comes with its own small wiring loom and wiring diagram. If you or a friend are a little technical and can solder a few wires, you can fit it yourself. We have Australian customers who have fitted it themselves.

2.  I noticed the 4-2-1 manifold doesn't have a flexipipe fitted. Does it fit into the stock flexi-pipe or replace it? I thought the flexi is supposed to help prevent the entire exhaust from cracking.
Our SWR header includes a quality spring loaded knuckle. It is much better than a flex. We have found that the flex can start disintegrating inside and block the exhaust slightly. The spring loaded knuckle replaces the flex.

3.  If I do get the manifold and the unichip, will it potentially create problems:

  • Would I need to do brake and suspension work after adding 20-30 bhp?
  • Will the car be louder with the manifold?
  • Will the mods trip the engine light in coming on?
  • I have also purchased a Mountune cold air intake and I know this and replacing the flexi pipe are the safest mods and you can potentially get 10bhp with just these.

You will not need to change anything like brakes or suspension. We have many happy customers worldwide running stock brakes and suspension. The Mountune intake will be perfect. The car will be slightly noisier, but you can fit a bigger rear silencer box. A 180 mm x 500mm long round free flow works well. It sounds great. With the Unichip fitted it takes care of your engine management light. Your car will be much more economical as well.

4.  In regards to the 4-2-1 performance manifold, will I lose any low end torque? What I like about the stock car is the low end pulling power from as low as 1500 rpm - it helps going up hills in 2nd and 3rd gear. The power range only lasts to 4500 - 5000 rpm then the car sort of doesn't push beyond that. I read the 4-2-1 can help with the mid range power band but at the same time will it sacrifice any of the low end power. Also with the Unichip, does it just have the one tune? If I decide to tune it back to the stock setup is this possible? Would this tune be similar to others on the market or is it designed to go with the installed SWR manifold?
Actually our SWR 4-2-1 is designed to give torque gains from under 2000 rpm all the way to the limiter. It is much better than the standard car lower down the rev range. You can run your stock exhaust system. It works perfectly.  You can just change the rear silencer to a nice free flow unit which gives a little extra power the bigger the diameter it is. We find that a 180 mm diameter by 500 mm round silencer works very well and is not noisy at all. The Unichip has one tune and is perfectly mapped for the SWR 4-2-1. It comes with a bridge plug. So you can unplug the Unichip and plug in the bridge plug and it configures the wiring back to standard which is great. Your XR4 will be much more economical on fuel as well.

5.  I am interested in fitting the Stage 1 kit. Will the cat need to be removed and how do I go about circumventing the on-board check that it's there.
Yes the cat is removed. The mapped Unichip takes care of the engine management light.

6.  Will the exhaust manifold fit into the current system or will I need to get a free-flow of some sorts?
You can fit it to your existing exhaust system. It works well.

7.  What type of steel is the exhaust manifold for the ST150 made of?
It's very thick mild steel. Stainless steel cracks, so we don't use it.

8.  I have SWR 4/2/1 on my ST 150MK6, very happy with the result. Is it possible to SWR Unichip Q + recalibrated Computer? I live in France. This will bring more performance?
It will make a big difference. It will give you around 8 kW more power and 15 Nm more torque.

9.  Does the performance manifold replace the catalyst? If so is there a way to keep the catalyst? I'm guessing the manifold won't work with the stock heat shields so they have to be ceramic coated, is that right?
Yes the catalyst is removed. You can fit a sport cat after the manifold. You don't need to ceramic coat it.  Here in SA we don't. It's fine and our climate is like yours in Australia. It's not really necessary. It only helps when you are racing around a race track at high revs all the time and there is a lot of heat build up.

10.  Does the engine need to be removed to install the performance manifold? I saw that it comes in two pieces, can top piece be slotted in from the engine bay without removing the engine?
We designed it as a 2-piece to make fitting so much easier. You don't have to drop the engine or anything else.

Continued... Part 2 here and Part 3 here