Downpipe for What! Mishimoto's Fiesta ST Downpipe R&D

[mishimoto1]

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 courdinate measuring machine (CMM) to collect some data about the downpipe.

Stock Fiesta ST downpipe on the CMM

Stock Fiesta ST downpipe on the CMM

We began with the most important component for fitment, the flange. As you can see in the photograph earlier in this post, it needs to be slotted so it can be installed properly. Both of our downpipe designs will feature the slotted flange for ease of install and fitment. Removal and installation of the stock downpipe is more like solving a puzzle than replacing a part. The downpipe needs to be twisted in just the right way to coax it out from behind the engine. That said, the downpipe has proven to be one of the more difficult of the Fiesta ST parts to design, based on where it is located. After we had our measurements, we printed a model of the flange with our 3D printer. Check out some shots as it?s being made!

The flange for the Fiesta ST downpipe being printed

You can also see my fellow blogger John?s modeling debut reflected in the printer. Way to go John! Our 3D model was test-fitted for accuracy on our Fiesta. After fitment was confirmed, we received our machined flanges for creating our prototypes. Check out some shots of the finished flange compared to our model below!

Comparison of the 3D printed flange and the machined flange

The machined flange being fitted with the turbo

The machined flange fits nicely with the turbo! Time to get started creating the rest of the downpipe.

Project Goals

We are planning to fabricate two prototypes for testing; a catted downpipe and a non-catted downpipe for race applications. Both will have similar designs coming off the turbo and meeting with the exhaust. Our designs begin with a 3? diameter (similar to the stock downpipe) and continue with 3? pipe all the way through to the flex pipe. A small step down after the flex pipe allows the downpipe to mate with a stock exhaust setup. Our downpipes will work with both the stock exhaust and our Mishimoto cat-back exhaust, which is also in the works!

Stock Fiesta ST downpipe next to Fiesta ST parts for the new downpipe

Coming Up!

Check back for more about the development of our downpipe setup. We?ll get a closer look into the design and fabrication of both our catted and non-catted downpipes!

Thanks for Reading!
-Sara

 

[GAbOS]

Keep the parts coming!

 

[rexdriver85]

Loving all of the community involvement. Top notch!

 

[2006ser]

niceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

 

[mishimoto1]

Keep the parts coming!

Loving all of the community involvement. Top notch!

niceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

Thanks for the kind words! (and the Eeeeees)
-Sara

 

[Boomba Racing]

Props to you guys! You are really going all out with your shop car. Keep the good stuff coming.

 

[Bonesaw]

sub'd!

 

[mishimoto1]

Props to you guys! You are really going all out with your shop car. Keep the good stuff coming.

Thanks for the kind words! Awesome to see you guys bringing some great products to Fiesta owners as well!

sub'd!

Thanks for the support!
-Sara

 

[RyFiST]

Looking forward to seeing this completed & available!

 

[mishimoto1]

Looking forward to seeing this completed & available!

Thanks for the support! We are really enjoying how this project is coming along!
-Sara

 

[mishimoto1]

Downpipe for What?! Mishimoto?s Fiesta ST Downpipe R&D Part 2: Creating the Prototypes

In our last post we took a look at the stock Fiesta ST downpipe as well as our slotted flange design based on the stock flange. We are still planning to create both a catted downpipe and a non-catted downpipe for race applications, so let?s take a look at the progress!

Downpipe Design

After fitting the flange to the turbo, we began to piece together the rest of the downpipe coming off the flange and meeting with the exhaust. Both our designs feature a slotted flange that bolts to the turbo, in addition to a flex pipe near where they meet with the exhaust. This is important because the entire exhaust system will move a bit, and we need a flex point to allow for this. Not allowing room for flex in the downpipe would most certainly harm your exhaust system and possibly the turbo itself.
We began by laying out the components of our prototype next to the stock Fiesta ST downpipe for comparison. Check out some shots below!

Layout of piping to create the catted Fiesta ST downpipe

Fabrication

This project is unique in that part of the fabrication was done with the prototype downpipe components installed on the car! The lower flange was created and welded to the flex pipe section, which was then bolted to the exhaust. All measurements were done with the stock exhaust to ensure excellent fitment, even if you choose to stick with the stock exhaust on your Fiesta!

Catted downpipe fitted on the Fiesta ST

The rest of the downpipe portions were fitted and tack-welded in place for the best possible fitment. This required some welding yoga to get the job done, but it was worth it! Check it out!

Welding some Fiesta ST parts

Fiesta ST downpipe on the turbo

Fiesta ST downpipe on the turbo

Once all the pieces of the downpipe were tack-welded together, the entire downpipe was unbolted and removed from the car so that it could be welded completely. These particular Fiesta ST parts required quite a bit of welding. Each portion of the pipe had to be welded together to form the perfect sequence of bends. Much like the exhaust, the welds must be perfectly leak free so as not to skew test results with a leak.

Welding some Fiesta ST parts

Flange welded on the Fiesta ST downpipe

The downpipes are starting to come together! Once we had the catted downpipe nearly complete, we repeated the fitting and welding process for the non-catted downpipe.

Creating the non-catted Fiesta ST downpipe

Creating the non-catted Fiesta ST downpipe

The non-catted Fiesta ST downpipe tack-welded together

The non-catted down pipe is tack-welded and looking good! We finished welding the entire downpipe in preparation for test-fitting.

Welding some Fiesta ST parts

Welding some Fiesta ST parts

The bracket is one of the final touches on this work of art. We want our bracket to be as close as possible to the stock bracket in both shape and location. This will allow us to achieve excellent fitment with both the stock and aftermarket exhausts! Incorporating a bracket into our design will provide for more secure mounting and prevent damage to the exhaust system (and possibly the turbo) resulting from too much movement of the downpipe. We tack-welded our bracket to the catted downpipe so we could check fitment of the completed prototype.

Tack-welding the bracket of the Fiesta ST downpipe

Tack-welding the bracket of the Fiesta ST downpipe

Tack-welding the bracket of the Fiesta ST downpipe

Drilling holes for the O2 bungs

Welding some Fiesta ST parts

Two holes were drilled in the downpipe to accommodate bungs for the oxygen (O2) sensors. We chose close-to-stock placement of the O2 sensors to allow for use with the stock sensors, making installation more straightforward. That?s all for our downpipe prototype designs! Check out some shots of our completed prototypes below!

Finished prototype of the Fiesta ST downpipe

Finished prototype of the Fiesta ST downpipe

Lineup of Fiesta ST parts

Finished prototype of the catted Fiesta ST downpipe

Finished prototype of the non-catted Fiesta ST downpipe

Coming Up!

As mentioned in our previous post, both our prototypes feature full three-inch pipe with a small step down after the flex pipe. By increasing the size of the downpipe, it allows the turbo to spool more quickly, which should produce an increase in power for this little Fiesta. Speaking of power, next up we will be testing to see what this downpipe can do. Check back to see Mishimoto?s Fiesta ST Downpipe take on the dyno!

Thanks for Reading!
-Sara

 

[tjd_tdi]

Love getting a view into the design process. Can't wait for the dyno numbers.

 

[mishimoto1]

Love getting a view into the design process. Can't wait for the dyno numbers.

Thanks for the kind words! We should be getting these downpipes on the dyno shortly!
-Sara

 

[FistSt215]

Let's here how the turbo back sounds

 

[mishimoto1]

Let's here how the turbo back sounds

Absolutely! We are currently doing testing for the downpipes with the addition of the cat back exhaust. We will share some footage of our Fiesta on the dyno in our next post, stay tuned!
-Sara

 

[M2-Motoring]

any update Sara?


hiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii

=)

 

[mishimoto1]

any update Sara?


hiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii

=)

Hi there!

We don't have any updates for you as of now, some development projects take a bit longer than others. We should have another update for you in the near future.

Stay tuned!
-Sara

 

[Zenga11]

Anymore updates on this thread? Like to here dyno numbers and when I can buy this thing!

 

[jeff]

Me too.... Been following all this R&D but no data yet?

 

[commonplatypus]

I had a quick question; as I will need to be finding a downpipe for any big turbo upgrade plans I have. How many cells are you using in your catted option? Everyone pretty much offers a 200 cell catalytic converter in their aftermarket downpipes, but I'm looking for something a little higher in count to help with emissions testing and odor reduction. I was wondering if the Mishimoto downpipe will be higher than 200 cells in count? I know the oem catalytic converter is somewhere near 800 cell, so getting somewhere a little closer to that would be ideal.