isthatahemi

So, after about 4 different exhaust setups on my 2019 2.7 - I am going back to an OEM muffler and tailpipe with a 3” resonator delete section. Unlike the 3.5, which sounds okay, the 2.7 sounds lousy.

OEM muffler is reasonably quiet, even with downpipes and 3” resonator bypass. Wouldn’t 2 OEM mufflers, piped in side by side, be quiet and have half the restriction?

Lets assume for the moment the truck is making 540 crank horsepower on an E55 blend of e98 race and 94 octane. I may upgrade the turbos next year and that should close in on 630hp or so. Inevitable arguments about actual power levels aside, I wonder 2 things, (and they are not the same for the knowns reasons regarding how power output is controlled on the ecoboost.)
-Actual restriction, in the form of backpressure
-Actual impact on max engine power output

So, I’m wondering if dual mufflers would help. Not really considering doing it, a mostly theoretical discussion.

Ecks

Why not leave stock exhaust and run cutouts?

isthatahemi

I run at the track maybe twice a year, but I’m out every Sunday night.......I want the best performance on the street.
Also - Cutouts would void my warranty.

BadCon

The stock muffler is a tuned unit, and by that I mean it is calibrated for the 2.7, displacement, firing order, etc, with resonance cancelling chambers and whatnot built in designed to mitigate annoying frequencies of that particular engine. While I'm pretty sure two in parallel would still be quiet, the tuned nature of the stock muffler means you don't know what kind of sound quality you would have. Not to mention those stock mufflers are huge, and not all that light.

Danengraham

What?? What warranty are you worried about? If the truck is making 500+ hp and your shooting for 600+ what are you talking about...

Ecks

I don't quite understand either. 4 different exhaust setups, downpipes, and resonator delete that won't void warranty but cutouts will?

Ecks

Exactly. How much extra horsepower would be required to overcome the additional weight. I don't think it would be worth it honestly.
If I knew then what I know now considering all of the different setups i've done and tested I'd leave my catback 100% stock and put two boost activated cutouts on my y-pipe. Simple yet extremely effective.

isthatahemi

It has stage3’s aftermarket power train warranty through 5 star.

isthatahemi

Yes. Never assume.

isthatahemi

The stock can is maybe 25 lbs (I have one sitting in my shop currently), but it is a bit big for sure. I don’t really care particularly about the sound (it should sound stock-ish), but my assumption would be that it would act like a single muffler with regards to tone, it allow the flow of 2 mufflers, I wonder if there is anything to be gained power wise though.

Partly a discussion on account of a good number of people going in circles to get quiet and best performance, a couple guys with multiple mufflers and resonators, which seems more work and less effective than 2 OEM mufflers

I take it from the replies that most don’t think the stock muffler is holding back much a 500+hp. Interesting.

FWIW - it’s not straight through as many seem to say, not sure how many twists and turns it has, but from having had 2 of them With the ends chopped off, there is no straight flow path on the ecoboost mufflers.