Is a 5.3 equal length single exhaust setup a viable option for performance?
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Teching In
Joined: Oct 2022
Posts: 15
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Is a 5.3 equal length single exhaust setup a viable option for performance? Apologies in advance if this is not posted in the correct area, it was the best option I could find.
I’ll be building an exhaust setup eventually for my 5.3 L33 swapped nova soon.
On my last 5.3 swapped nova I created a 2 into 1 equal length exhaust system using 2.5” diameter pipe, I really liked the sound of it, I found it more consistent and less choppy, something I prefer. Also the fact that it is lighter and cheaper to create.
I would really like to do it again on my new Nova but I’m thinking of going with a bigger diameter as to not hinder performance, maybe even merging the two smaller pipes into a larger diameter at the Y.
I would like to make around 400hp as I believe that’s reasonable in a naturally aspirated setup.
Is an equal length single exhaust system viable for such goals? Anyone have experience with this?
I’ll be building an exhaust setup eventually for my 5.3 L33 swapped nova soon.
On my last 5.3 swapped nova I created a 2 into 1 equal length exhaust system using 2.5” diameter pipe, I really liked the sound of it, I found it more consistent and less choppy, something I prefer. Also the fact that it is lighter and cheaper to create.
I would really like to do it again on my new Nova but I’m thinking of going with a bigger diameter as to not hinder performance, maybe even merging the two smaller pipes into a larger diameter at the Y.
I would like to make around 400hp as I believe that’s reasonable in a naturally aspirated setup.
Is an equal length single exhaust system viable for such goals? Anyone have experience with this?
Last edited by NovaKeagan; Feb 19, 2025 at 12:51 AM.
TECH Senior Member
Joined: Jun 2016
Posts: 22,293
Likes: 3,617
From: Central Cal.
If you come off the headers with smooth bends and a good merge like Flowmaster makes, being equal length isn't that critical to sound and power output. Run decent lengths (2-3 feet) from the headers, aiming toward the center of the car but meeting to one side of the driveshaft. A few inches difference won't make an appreciable difference in sound or power as noted above. Just make sure you use tubing big enough, but not so big that flow velocity is hampered. For a 5.3, two 2.5" pipes into a 3" single will actually flow very well. Larger engines will need larger pipes.
Staging Lane
Joined: May 2025
Posts: 68
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Actually according to the diameter to HP rule I've seen for 400-450 HP you need 3" dual pipe and 4" single so I'd go with 3" off the headers to the Y-pipe and then go 4" out to the rear but for best power and if you want it quieter instead of merge go with true duals. Add an H-pipe (makes it a few db quieter but adds some HP and torque till 4k RPM. Go 3" to mufflers but then go 2.5" out the rear (as gas cools it contracts and needs less pipe so this saves weight, keeps velocity high and helps scavenging) but if you prefer do the merge but use right size for the HP your making
On The Tree
Joined: May 2023
Posts: 116
Likes: 4
Actually according to the diameter to HP rule I've seen for 400-450 HP you need 3" dual pipe and 4" single so I'd go with 3" off the headers to the Y-pipe and then go 4" out to the rear but for best power and if you want it quieter instead of merge go with true duals. Add an H-pipe (makes it a few db quieter but adds some HP and torque till 4k RPM. Go 3" to mufflers but then go 2.5" out the rear (as gas cools it contracts and needs less pipe so this saves weight, keeps velocity high and helps scavenging) but if you prefer do the merge but use right size for the HP your making
