Page 7 - ecoboost

Introduction and the Stock Downpipe

Another addition to the Fiesta ST collection! Our Fiesta build is coming along nicely, and I am happy to announce some progress on our downpipe project. As with any R&D undertaking the first step is to take a look at the stock setup and see how it can be improved.

Stock Fiesta ST downpipe

Although Ford has a pretty nice design, we are planning to make it a bit better by increasing the diameter of the downpipe to 3" throughout. As opposed to the stock unit which features 3" pipe only where the downpipe meets the turbo. In order to achieve excellent fitment with the turbo, we will keep the flange as similar to stock as possible. To collect the most accurate measurements of the flange, and other Fiesta ST parts, we placed it on our coordinate measuring machine (CMM) to collect some data about the downpipe.

The stock Fiesta ST downpipe on the CMM

The stock Fiesta ST downpipe on the CMM

We began with the most important component for fitment, the flange. As

We're getting closer to dyno testing! Our intake piping and turbo inlet hose are now complete. A well-designed airbox is the last portion of our intake design before we begin performance testing. The airbox will provide a shield for the filter to reduce the impact of engine bay heat. It also allows us to create a volume for cold air to enter from the stock duct, routing directly to our filter.

The airbox design was pretty extensive for this project, so this is a long post. Sit back, crack open your favorite beverage, and read on!

Airbox Fabrication

We started this process with cardboard templates. These templates helped us quickly adjust and modify the shape and bends until we had a design that provided for appropriate clearance. The space between the battery and air duct is quite slender, so the design will need to be precise.

Ford Fiesta ST intake airbox cardboard template

Below is a look at what we have to work with regarding the stock duct. As you can see, the duct routes downward before

We've logged some miles (and smiles) during the testing of our two cat-back exhaust setups. We've decided on a strategy for the muffler selection, one that we feel best suits the tones of the Mustang EcoBoost (EB). Our team determined that the round muffler setup is just a touch too loud, and that the oval mufflers shown in the previous segment provided the exact sound we are seeking. Months of tedious design and testing have resulted in drone-less operation on the highway, improved volume at wide-open-throttle( WOT), and stock-like sounds during light/partial throttle.

I am sure you guys are eager for some final sound clips, but you will have to wait just a bit longer. In the meantime, we've settled on the muffler tip we will be using, and we've fitted it to our final prototype. Check out the process below!

Tip Design

We've gone with an appealing tip design for our EcoBoost Mustang exhaust system. Check out a few shots prior to mating this with the rest of our system.

Mishimoto 2015 Mustang

This is a pretty cool post, something a bit out of the ordinary for our projects. We typically utilize our existing silicone boots in our intercooler kits, intake systems, etc. For this project, we decided to manufacture the first portion of our intake system from a wire-reinforced silicone hose. This would facilitate an easier installation, and it would also provide a smooth airflow transition from the small turbocharger compressor inlet to our intake's large pipe diameter. Since we like to show you what goes into developing our prototypes, check out the process for creating our silicone turbo inlet hose below!

Printing Our Fixture

The hose we have in mind will follow the path of the stock induction hose, which is actually a plastic piece on the stock ST. Before beginning our silicone project, we needed a fixture that would serve as a base for the silicone layers that will be applied. After making a model in Solidworks, we fired up the 3D printer and watched as it churned out our component.

Now that we had a ton of information and data points for the stock intake system, it was time to begin creating our own design.

Piping Fabrication

We're starting our intake system at the turbocharger and working to the airbox. We intend to place our box in the same location as the stock unit so we can take advantage of the stock cold-air duct.

We switched on the band saw, fired up the welder, and started tackling the route for our prototype pipe. Our first length runs from the turbocharger around to the rear of the valve cover.

Prototype Fiesta ST parts

Prototype Ford Fiesta ST intake piping fabrication

Next we made the bend to turn the pipe around the engine toward the front of the vehicle.

Prototype Fiesta ST parts

You will also notice that we've added a bracket that attaches the pipe to the valve cover for support. This bracket incorporates the stock rubber grommet to provide flex and isolation during engine movement. Here is a close-up shot of the bracket!

Prototype Fiesta ST intake

As many of you are aware, here at Mishimoto we have been going Fiesta crazy developing various Fiesta ST parts such as;

• Performance Aluminum Radiator
• Oil Cooler Kit
• Performance Air Intake
• Direct-Fit Baffled Oil catch can
• Downpipe and  Intercooler/Piping coming soon!

Up next is something that the team here has been very eager to start development on, the Fiesta ST Cat-Back Exhaust! We are excited to let you in on the details of the development of our first prototype. As with any exhaust project, we are shooting for improvement in flow over stock as well as a great overall tone that is drone-free. Check out the details and let us know how we did!

Stock Component

To begin, we gave the Fiesta ST's stock exhaust setup an once-over to see what we were working with. While it is not terrible, we do see some room for improvements. As you may have noticed, the stock exhaust has two mufflers. One rather large with small dual tips exiting the back of the Fiesta, and the other farther forward closest

The search continues to find the optimal blend between a high-quality WOT (wide-open throttle) exhaust sound and a rich sound during normal driving and light-throttle driving situations. In this segment, we continue with our 2015 Mustang exhaust sound testing to see if we find our second or third prototype setup pleasing.

Dyno Testing

We set up our EB on the Dynapack for some more sound collection. We also kept an eye on power output and AFR readings to see if power changed on the factory tune, and to see if the improved flow would impact AFRs in any way. On our 2015 WRX, we saw these readings lean out a bit with the cat-back installed, so we wanted to see if this was the case with the 2.3L!

Preparing for 2015 Mustang EcoBoost exhaust dyno runs

Preparing for 2015 Mustang EcoBoost exhaust dyno runs

Cue the camera and fire up the four cylinder! Check out a video compilation of our runs comparing the stock exhaust to our 2^nd and 3^rd prototypes of the 2015 Mustang exhaust systems.

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