Enhance Your EcoBoost Exhaust! Cat-Back Development, Part 3: Prototype 2 & 3 Testing

Enhance Your EcoBoost Exhaust! Cat-Back Development, Part 3: Prototype 2 & 3 Testing

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

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 2nd and 3rd prototypes of the 2015 Mustang exhaust systems.

Well"that was fun! In addition to drawing a crowd from our corporate team and making numerous runs, we recorded a ton of very useful information.

We first focused on the volume, which was the primary reason for this 2015 Mustang exhaust test. The second prototype setup sounded great. It was louder and more throaty under heavy throttle, yet smooth and refined at idle and when rowing through the gears at low rpm. Our third Mustang EcoBoost exhaust prototype has smaller round mufflers and was a touch too loud for our liking. This was nearly identical to our conclusions for the last cat-back project we had in the shop. The additional sound will only be enhanced with the addition of a larger downpipe. We want this 2015 Mustang EcoBoost exhaust to provide a nice tone when ripping to redline, yet it should still be drivable (in terms of noise on the highway and normal driving) with both a stock and larger diameter downpipe. We plan to test this out a bit further in the future to ensure our selection is ideal. This initial testing has us leaning towards our second prototype, but we would definitely like to conduct some further testing. There is only so much we can gather from testing in the garage. Soon we will be hitting the road with our second 2015 Mustang Exhaust prototype to investigate further.

We also learned about the impact of the larger cat-back on EcoBoost power output. In our case, variances in power were negligible after opening up the CBE portion of the 2015 Mustang EcoBoost exhaust. We know the addition of a downpipe and tune results in huge power gains, but it seems as though the cat-back upgrade will be an upgrade for sound/aesthetics. In addition, AFR was unaffected by the cat-back swaps during testing. All vital sensors saw appropriate readings and it appears this upgrade will function perfectly on the factory tune. Great news for our Mustang EcoBoost exhaust!

Downpipe + Cat-Back Adapter

We've provided some information about this adapter in the past few articles, but never actually provided a look at it. For those planning to run both our 3" downpipe and our larger cat-back exhaust, an adapter is needed to avoid necking the exhaust down to the factory inner diameter.

This piece has a v-band connection which attaches to the downpipe and a slip-joint clamp which attaches to the cat-back portion of the exhaust.

Mishimoto downpipe adapter for large diameter Mustang EcoBoost exhaust
Mishimoto downpipe adapter for large diameter Mustang EcoBoost exhaust

Mishimoto downpipe adapter for large diameter Mustang EcoBoost
Mishimoto downpipe adapter for large diameter Mustang EcoBoost

Coming Up!

With our selection narrowed down, we only have a few more steps in our process before we can start producing this cat-back exhaust. Next on the list is road testing with our prototype exhaust selection. Once we log some miles with our team members, we can have a discussion as to any adjustments that need to be made in terms of fitment, sound produced, etc.

Assuming our team is pleased with the sound during final testing, our next post will include some higher quality video from our professional video team featuring clips during all driving conditions. This should give you a better idea of the sound you can expect with our setup!

Thanks for reading guys!

-John