Worth going full 3" exhaust?

So I've been doing my usual reading and have a question; what would be better, a 3 inch catback or a 2.5 inch like the magnaflows. Of course down the line I plan to get a 3 inch O/R downpipe anyways but my question is would a full 3 inch exhaust be significantly more beneficial to the 2.5 inch system since this is indeed an FI car?

Over 600 HP I think you could see some benefit performance wise.

Sound wise it would help deepen the tone.

No benefit at all since the DP and half the exhaust is a single 3" or smaller anyhow.

How about a 3" down pipe with high flow cats then y pipe tapers down to 2.5" dual vs a full 3" dual?

ELPYBOOST said:

How about a 3" down pipe with high flow cats then y pipe tapers down to 2.5" dual vs a full 3" dual?

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Its unlikely you will lose any real power at the normal mildly modded levels these cars make. I prefer the sound of a 2.5" pipe on these cars personally.

ForYourOwnGood said:

Its unlikely you will lose any real power at the normal mildly modded levels these cars make. I prefer the sound of a 2.5" pipe on these cars personally.

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I got a SOLO turbo back exhaust without all the resonators. Which is 2.5" from the y pipe the rest are 3". Sounds nice I was just wondering what it would sound like if I went full 3"

I'm rockin the mishi catted dp and Mbrp street with a vibrant ultra quiet resonator in place of the step down to make it a true full 3" turbo back and it it's really deep. Unfortunately with deep comes drone :(

Got a full 3inch exhaust with 1&7/8 headers and 100cell cats and cai and tune done.

Couple of vids in links below.

Experience on other platforms leads me to believe that 3" is the way to go for big power:cheers:. If I were to go full bolt-ons , or run meth injection, e85, or portfuel I'd go 3". If my end goal was to have a fun daily driver, I'd go 2.5".

I am interested in this as well...specifically is a better downpipe only going to be really beneficial if you get a 3" exhaust?

Reason being that I want the Borla ATAK for the sound, but the piping is extremely small at 2.25"...

I know for me personally I didn't notice a difference in power at all between stock and the 3" MBRP, I felt more from my DV+. It actually felt slower with the loud exhaust because it tricks you brain into thinking you're going to go fast in proportion to the amount of noise it makes.

MM Pony GT said:

Got a full 3inch exhaust with 1&7/8 headers and 100cell cats and cai and tune done.

Couple of vids in links below.

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His car is an ecoboost. No headers and a single cat.

I think it's also worth mentioning that for best results after changing your exhaust parts out, following up with a tune for the parts installed will yield the best results.

The single 3" section will always be the smallest point, the dual 2.5 actually has more flow area than a single 3". That being said, i had a single 3" all the way out, and have just stepped to the dual 3" to make my diffusor fit.

MM Pony GT said:

Got a full 3inch exhaust with 1&7/8 headers and 100cell cats and cai and tune done.

Couple of vids in links below.

Click to expand...

i think you are in the wrong section