downpipe

Downpipes are a choke point in many turbocharged vehicles when it comes to exhaust flow. As opposed to naturally aspirated cars, less serious thought needs to go into the size of the exhaust piping. In most cases the system just needs to be bigger in diameter, maximizing what you can within the alotted design space.

The downpipe on the Camaro 2.0T's LTG engine is a restrictive point in the exhaust system, a conclusion brought about by our testing. The point of emphasis is the rate at which exhaust gases are expelled out of the turbocharger. That flow is very important to how well the turbocharger can do its job. If you can flow more exhaust gases, the turbine can spin faster, leading to more boost. It is now time to test the prototype and figure out what our downpipe design can do for this LTG power-plant.

Production sample of our downpipe!

There is a noticeable difference in sound. Even with our catback and intake on the car, you can hear a much throatier and raspier exhaust sound. This

I think we can all agree that the past couple weeks have been quite eventful here in the United States.

Regardless of which political candidate you supported, it's time to move on and unify now that our election has concluded. Whether or not we're happy about the outcome, we - as a society - need to be working together now. But certain Facebook friends can't seem to figure that out. You all know the one(s). Regardless of their political allegiances, they flood our news feeds with statuses high in pressure and often full of hot air. It's utterly exhausting - if only there were some way to get these people to pipe down.

The Camaro downpipe connects to the back side of the turbo.

Well here's an unpopular opinion for you" let's find a good, level-headed automotive engineer and elect him or her as the next president! Because if our goal is to exhaust the high pressure and hot air out of our system, they've already got that figured out - it's called a downpipe, ladies and gentlemen, and there's

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.

Fiesta ST parts

Final Prototype

Our final prototype arrived today and we wasted

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

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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