JustAnotherVictim
Supramania Contributor
Having upgraded one and the other I feel the cat back more.
Doesn't kick in as quick but the pull feels harder.
Doesn't kick in as quick but the pull feels harder.
Exhaust Question, been bugging me
- Thread starter Snotcycle
- Start date
hmm im surprised no one has mentioned it but the common sizing for exhausts on v8s such as mustangs are dual 3 inch... Magnaflow even makes custom 3.5 inch systems. I'm not trying to prove anyone wrong or start shit, but what could be the explanation for this?
Much higher displacement. I know it's not double that of ours, but aren't their exhaust systems also shorter? Hence less cooling of exhaust gases in transit.
I'm not convinced that 2.5" is the biggest you could go on an N/A before loosing performance. Our stock resonators and mufflers are baffled and restrictive, the piping is crushbent and has 90º bends... with these facts in mind a smaller diameter is needed to prevent the exhaust from cooling too much before it exits the system. I rather doubt that an unrestricted exhaust system (high flow cat, straight through resonator and muffler) running as straight as possible couldn't be built with larger piping. Minimal restrictions and a good header (AFAIK - this is where the scavenging is the most important/helpful) you could most likely build a 3" N/A exhaust and see a benefit.... the question is if it's worth the trouble for such a small gain.
I'm not convinced that 2.5" is the biggest you could go on an N/A before loosing performance. Our stock resonators and mufflers are baffled and restrictive, the piping is crushbent and has 90º bends... with these facts in mind a smaller diameter is needed to prevent the exhaust from cooling too much before it exits the system. I rather doubt that an unrestricted exhaust system (high flow cat, straight through resonator and muffler) running as straight as possible couldn't be built with larger piping. Minimal restrictions and a good header (AFAIK - this is where the scavenging is the most important/helpful) you could most likely build a 3" N/A exhaust and see a benefit.... the question is if it's worth the trouble for such a small gain.
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I installed a full exhaust on my friends '03 mustang GT, headers back. The exhaust piping on his was 2.5"....
the only reasons i could see the bigger pipes is because its usually used in conjunction with headers, the headears sometimes have 3 inch collectors.
also because baffeled mufflers are used. on our cars most everyone uses a streight threw muffler. with a streight threw muffler theres little to no restriction. in a baffeled muffler theres a much larger restriction because the gasses have to change direction a number of times. since threres this restriction they make the passeges bigger and use larger piping so that the resctiction is reduced. the baffels in the muffler are suposed to be designed to promote exhaust scavenging but i think a streight threw exhaust tuned to the right rpm, power level, and displacement of the motor is the best way to go.
although most exhaust systems ive seen for mustangs and camaros are 2.5 inch.
also because baffeled mufflers are used. on our cars most everyone uses a streight threw muffler. with a streight threw muffler theres little to no restriction. in a baffeled muffler theres a much larger restriction because the gasses have to change direction a number of times. since threres this restriction they make the passeges bigger and use larger piping so that the resctiction is reduced. the baffels in the muffler are suposed to be designed to promote exhaust scavenging but i think a streight threw exhaust tuned to the right rpm, power level, and displacement of the motor is the best way to go.
although most exhaust systems ive seen for mustangs and camaros are 2.5 inch.
CRE said:
a 3 inch exhaust would be suitable for a more race application on a non power adder 7m. it woud need to stay up in the rpm range most of the time to be benificial at all. a 3 inch exhaust along with cams, P&P head, high compression and a larger throttle body/ITB's would definatly be better then the same combo with 2.5. if u feel 2.5 inch isnt enough, weld in a wideband 02 bung and use a backpressure gauge and post your results.
the mustang might have more displacenemt but dont forget a 5.0 mustang is only using 2.5 liters threw each side of the dual exhaust.