Cat size and my Frankenstein exhaust

[RevNev]

thus less "sticky boundary layer" actually makes the 3.5" single flow slightly better than dual 2.5"

What I've discovered dyno testing, is that twin 2.5" and single 3.5" makes the same power providing the collector into single 3.5" isn't restrictive. Despite the slightly greater volume of twin 2.5", I've never seen either make a power difference to conclude that one is better than the other. Mostly boils down to what fits the chassis best and if someone's paying, their preference is usually the cheaper option.

 

[daves8]

I totally understand I won’t get any increase in performance now….

What would be the difference in volume and depth of note going to a bigger cat and cat pipes before the twin 3 inch DPE.

I am more into note than performance, I’m a old man these days!

 

[PeteSS]

I've never seen a naturally aspirated VE/VF road car engine with enough horsepower to benefit from a 3" exhaust yet. I think 3" was ideally produced for supercharged engines that can use it.

sorry, i should've stated mine is supercharged

 

[someguy360]

I think 99% of people that do 3" do it for the sound not the performance on a street car.

3" does sound better but it's not gonna make it faster unless your pushing some serious power.

 

[daves8]

I think 99% of people that do 3" do it for the sound not the performance on a street car.

3" does sound better but it's not gonna make it faster unless your pushing some serious power.

Yep that’s me. I’m all about the sound.

I’ve got a little over 300rwkw and a 3.45 diff, it goes fast enough for a old man…… I just want the deep sound!

 

[RevNev]

Yep that’s me. I’m all about the sound.

Note wise, the muffler configuration has a greater effect than pipe size in most cases. A 3" X-Force sounds lousy in my ears compared with a 2.5" Magnaflow that sounds pretty good!