2017bluetruck

Possible swap of exhaust parts? I have a full OEM system from my 2.7 in a barn. KM

w00t692

I put one good magnaflow resonator with the largest magnaflow muffler out back on a 3" setup and it was very very quiet at WOT. Basically the only place you could hear it was at low rpms when the wastegates are open bypassing all the engine sound out the exhaust, when the wastegates close it was basically sleeper mode.

isthatahemi

I wonder which would flow better? 2 OEM In parallel or 1 res / 1 high flow muffler in series?

load97

I think to keep it simple, just do a resonator with a muffler. For sure 3" off the downpipes back like woot said. Maybe running a 4" resonator & muffler back would help offset any possible back pressure. There is calculators online that help give a good idea of exhaust size vs horsepower (granted need a calculator for turbo vehicles). It's been a month since the post so curious what you came up with, or put on the back burner?

Also, there's almost nothing for any kind of dyno's that show HP/TQ increase (or loss) by swapping out downpipes, turbo adapters, or full 3" exhaust systems. Though, there seems to not be that many people interested in going past a cookie cutter tune. Possibly because it's a truck, or just society in a whole dwindling on performance enthusiasts.

isthatahemi

Here’s another way to look at this, if you ran a cutout, and hooked up a second OEM muffler (bear with me....) you’d have half the backpressure from that point on, and very little additional noise.

It seems to me to be a solid theory....but only at well above stock power levels.

Fast Old Fart

Yes I think a larger exhaust would help power levels especially on the upper half of the rev range. We all know moving up to larger turbos and with a small exhaust would make the turbos lag as well. That said two oem side by side or even offset won’t fit in the tunnel. They will fit after the axle though. In the tunnel for side by side the biggest you can fit case wise is 4x9 sized muffler or a 5x9 offset. If you want quiet you’ll have to increase muffler volume. The bigger the case the more room for exhaust gas to expand and cool. Also the gasses inside the muffler body act as a damper to pressure waves created by the exhaust pulses. The stock mufflers use pipes cut to certain lengths that vent into chambers of a certain volume mathematically calculated to cancel out certain frequencies.

In your application running a dual exhaust after the down pipe just adds weight and complexity. How handy are your with a welder or how much are you willing to pay for someone who is? A single 4” would be optimal but it’s loud. You still would have to modify the j pipe. That’s the usual choke point. If it’s only 3” then no matter how big you go after that it won’t matter. If you’re stuck at 3” there the only option is to shorten the exhaust to increase flow. Like using a dump right after it.

If you’re handy at welding an option to try since they’re cheap would be to get another stock muffler and do some surgery. Cut open the stock muffler and remove the pipe that goes through it. Get the diameter pipe you want to run and attach the small tubes from the stock muffler to the pipe in the same positions. Then weld it all back together. It will be louder but it will cancel all the same frequencies the stock muffler does. Add a resonator before it and it should be quiet at idle loud on the pedal.

What about cutting the y pipe out and attaching a stock raptor exhaust?