FiST

We are back with more on our Fiesta ST downpipe project. We know you are long overdue for an update, so we'll dive right in. After fabrication, we read that some other aftermarket downpipes for the Fiesta ST weren't as successful at making power as downpipes typically are on other applications. We still wanted to test our downpipe designs to see the data for ourselves, and decide if the downpipe was worth manufacturing for the Fiesta ST.

After testing was completed, the data confirmed our suspicions that the Fiesta ST is pretty darn efficient on its own, and the addition of a downpipe did not show any gains in power. Even still, we have decided to kick this into production for those who want the sound benefit, and for those who have more modified Fiesta STs.

A tune will be required to run this downpipe, and of course actual power gains will depend the tune itself and the supporting modifications to your ST.

We are narrowing down our selection of core designs through both extensive research and some pretty neat testing processes. After seeing some impressive heat transfer numbers on our first round of Ford Fiesta ST intercooler testing, we decided to focus on producing a better balance between pressure drop and reduction of intake temperatures.

New prototypes were constructed, and we were ready to make some dyno runs.

Testing Fiesta ST performance parts

Testing

The testing of our Fiesta ST rear strut brace involved three different driving conditions.

Cornering: 30-40 mph, slalom

Braking: 50-0 mph, stop with ABS engaged

Acceleration: 0-60 mph, full-throttle run

Each setup (with and without brace) was tested on the same day on an identical surface and with the same driver. The tests are repeatable and will provide an accurate comparison of rigidity in the rear body portion of our Fiesta.

Results

Check out the plot below to see our testing results.

Fiesta ST performance results

These data points confirm our theory that the addition of bracing in this area of the ST does indeed have an impact on flex. Although flex in these

With our final prototype in hand, our team went to work bolting everything into place. We've made minor tweaks to the design, so we just want to be sure fitment is spot-on for our final iteration.

Check out a few shots from the final install.

Ford Fiesta ST Intake fully installed

Ford Fiesta ST Intake fully installed

Everything bolted on perfectly, and this setup looks quite nice in the engine bay of the Fiesta. We will be making one small

Our quest for the perfect intercooler core continues! So far we've perfected the fitment and size of our intercooler core. Our final task is to adjust internal fin composition to create a perfect blend of pressure retention and temperature benefits.

Prototype Ford Fiesta ST Intercooler Fabrication

Timing is a bit of a concern for us at this time. This project has been lengthy, but it will be worth the effort and time when we know our best efforts have been captured in our final product.

Our final version of this intercooler will likely feature a tube-and-fin core. The benefits of weight and airflow are too important to ignore, not to mention the temperature drops we are seeing with a strategically designed internal core.

For our team, the creation of a bar-and-plate cooler is a much quicker process. We've found that pressure drop between the two core types is similar if fin style, density, or both are the same. So for this test, we are using two bar-and-plate

In our last update, we left you with some mock-up prototype pieces that we used to create and refine our Fiesta ST rear strut brace design. Since then, we've worked up a couple of functional prototypes to test our ideas for stiffening the rear of this hot hatch.

Initial Prototypes

We constructed two prototypes of this trunk brace. The first prototype is finished in a black powder coat, and we'll use this unit to evaluate for aesthetics and fitment. The unfinished ("raw") prototype is going to be used for testing purposes, meaning it will be modified.

First, check out our powder-coated unit bolted into place.

Mishimoto Fiesta ST performance parts

The most exciting part of product R&D is always the testing phase. This typically includes setting up some neat sensors, running the car on the dyno or on the street, and crunching our data. We are anxious to see how our first prototype coolers perform on the Fiesta. Let's jump right into the plans for this first round of testing.

Testing Plans

As mentioned in the previous segment, we will test four different coolers.

• Stock intercooler
• Mishimoto bar-and-plate prototype 1 (larger internal bar height)
• Mishimoto bar-and-plate prototype 2 (smaller internal bar height)
• Mishimoto tube-and-fin prototype

For each cooler we will be collecting data for temperature, pressure, and power output. Each cooler will be tested repeatedly until we have three consistent runs producing data as accurate as possible.

Below is a look at the three different core types that will be tested.

We are quite excited about the completion of our final prototype intake for the Ford Fiesta ST (FIST)! After months of development, testing, and design work, we are ready to present our final creation. First we will go through each component and cover important details regarding their features.

Silicone Turbo Inlet Hose

Starting at the turbocharger compressor inlet, we have our silicone inlet hose. This piece was constructed specifically for this kit and is extremely robust.

Mishimoto's Ford Fiesta ST intake silicone inlet hose

Five layers of silicone comprise this hose, along with embedded fibers and steel wire for added rigidity. This hose must withstand the suction

We are nearing the completion of this project. Our engineering team is ready for dyno testing that will verify any power gains made with our larger-diameter intercooler piping. Exactly how much larger is the piping we designed?

The Mishimoto hot-side design provided the greater increase in volume between the two, coming in at a 51% increase over the stock pipe.

Fiesta ST charge