Fiesta ST COBB Stage 3 Power Figures

The 1.6 Liter engine in the Ford Fiesta ST is one brilliant little engine. At that size, when it comes to power outputs even after bolt-ons, you cannot have that big of expectations. Or can you? Let’s look at the RallyWays Fiesta ST COBB Stage 3.

The purpose of this article is to unveil the performance gains of my Ford Fiesta ST, aka #RallyFist. The comparison is from stock to COBB Tuning Stage 3 for Fiesta ST.

I had a pretty good idea of what to expect going from a completely stock Fiesta ST to Fiesta ST COBB Stage 3. Before I acquired my kit, there were already a few stories and videos going around stating average results. But, one thing is to read about others’ experiences and a whole other thing is to try it for yourself.

Let me point out that this story got delayed. My original intention was to release this a while back. What happened was that the purpose of this project has always been about catering to the do-it-yourselfers out there. The idea is to empower those that are weekend mechanics like myself. You buy your Fiesta ST, Focus ST, Mustang EcoBoost, Subaru WRX or whatever, order stage packages from COBB Tuning, and install them in your garage. Of course, if you are not as confident with a wrench, you can still do the same… Just that you take the car and the parts to a pro shop to install them. Or you order through your tuning shop. You get the point.

The story got delayed a few weeks because after I was done with the installation I took the car to the dyno at HG Motorsports in San Diego, only to discover I wasn’t hitting the numbers because I had a boost leak. The issue was very simple, the clamps that hold the charge pipes to the COBB intercooler weren’t tight enough.

I thought they were, because I tightened them pretty well. But as rubber is, it compresses a bit more over time so the seal ended up too lose after a few heat cycles. The issue was a very simple fix, I just lifted the car and tightened them some more. This is something I’ll know for next time. I think the best option is to tighten it all down nicely and then after a few hundred miles check again, after the system has settled in.

After taking care of my leak I noticed this really high-pitch whistle I had gone away, and I was again in business.

Now, don’t let me scare you. The installation was straightforward and relatively easy. The parts all fit perfectly. You can learn more about the installation by reading some of the articles I’ll list at the end of this story. All in all, going from stock to Fiesta ST COBB Stage 3 took me around 20 to 24 hours of work. This could likely be translated to 4-6 hours at a pro tuning shop. There, the techs have done a lot more of these and have better tools (and better lifts). But me, in my garage, and being as meticulous and as a perfectionist as I am, took me a little over 20 hours.

So, I took #RallyFist (notice I always put the hashtag there. That’s so you will go and search for it on social media) back to HG Motorsports where Mike Petruzzo was again happy to run the car one more time.

Here comes the good part. The gains exceeded my expectations. See, from the research I had done, I was expecting to get an extra 25 horsepower and 50 LB FT of torque at the wheels.

Ah, but I got more than that! Take a look:

Ford Fiesta ST COBB Stage 3 Gains:
30 HP / 80 LB-FT Torque (at the wheels)

That’s very big and I’m very pleased.

Check out the video of the dyno run at HG Motorsports

If you don’t think these are substantial gains you don’t know 1.6 L engines and are probably used to bigger motors. On a 1.6L engine and a car that weighs 2,700 lbs, these are really good gains.

So let’s see. I got 5 more horsepower than I expected in the first place and another 30 Lb-Ft of torque more than I was counting on. Wow. I knew that I could feel the newfound power in the seat of my pants, but seeing the actual number is also super exciting.

Disclaimer: Keep in mind, other folks have gotten less, some more. Results may vary. The dyno we used is Dyno Dynamics, which reads really accurately, but the readings are really low compared to other dynos. To ensure consistency, we used the same dyno for baseline readings as we did for the COBB stage 3 readings. Then, to get more translatable numbers, the figures are converted to DynoJet for better comparisons.

For more info check out these more detailed figures:

Ford Fiesta ST Horsepower Stock (DynoJet)

Wheel horsepower: 181 HP
Wheel torque: 220 Lb-Ft Torque

Ford Fiesta ST Cobb Stage 3 (DynoJet)*

Wheel horsepower: 211 HP
Wheel torque: 300 Lb-Ft Torque

*COBB Tuning Stage 3 OTS (Off the shelf) map for 91 octane pump fuel

For a gain of 30 HP / 80 LB-FT Torque (at the wheels)

Check out the dynograph below for the representation of those numbers and the power curve. Red is stock, green is COBB Stage 3.

Notice the higher redline on the Fiesta ST Cobb stage 3 tune. Not that it will help all that much as the stock turbos on these cars are tiny so power near redline is nowhere near as good as power in the midrange. That said, on the street, midrange matters the most.

Refer to the following articles for more details about this build:

For the write-up about the baseline dyno run:
Fiesta ST Horsepower Baseline Numbers at HG Motorsports

For the entire parts list on this Fiesta ST:
RallyWays Fiesta ST Parts List – #RallyFist

For details about the COBB Downpipe and installation:
COBB Fiesta ST Downpipe Roaring Upgrade

For details about the COBB Front Mount Intercooler for Fiesta ST:
COBB Fiesta ST Intercooler Upgrade

For more details about the COBB Tuning stage packages and how they relate to our Fiesta ST build:
COBB Tuning Ford Fiesta ST Stage Packages

Fiesta ST COBB Stage 3 Conclusion

The COBB Tuning Stage 3 package for the Ford Fiesta ST does wonders for this already awesome turbo hatch. When I first was working on this project I was only driving the car sporadically and to shows. Now that the project is much more developed I’ve been driving it nearly every day. This has given me a deep understanding of how the system feels. It’s wins all around. The sound is great, the power is super obvious and the fun factor is over the top. Furthermore, the drawbacks are almost nonexistent. The only drawback I’ve been able to find is a bit more vibration added to the car, specially at idle with the A/C on. But this is just nitpicking and it doesn’t bother me at all.

The car feels like factory, but faster and way more responsive. There are other benefits to investing in a well-designed and tested system, even if it costs a little more than the alternatives.

The car idles perfectly well, heat management is spot on and the car starts immediately upon pressing the start button, just like factory — Every single time. It can do long trips just fine. I drove it to Vegas and back for SEMA 2015. I drive it in traffic and up and down mountain passes. The car does stupendously well in every situation I’ve put it in.

One thing that used to worry me about modding cars is that you often get more power in exchange for drivability in every day situations. This has not been the case with the Fiesta ST COBB stage 3 system in my car. I have logged a couple thousand miles now since completing this project — One great reason to have delayed showing the results. The car is as drivable as it was when I first bought it, only a lot faster and a whole lot more fun.

Share this story with your turbo friends. Don’t keep it to yourself.