2.5in vs 3in Exhaust

[nrothaar]

I know this has been discussed before and I have researched this topic for over an hour now and am still debating between a 2.5in or 3in exhaust. I currently have a 2.5in Borla Atak awaiting shipment due to it being back ordered and I am considering switching to the 3in version. I am looking to put on an H-pipe with this system as I already have the H-pipe and hope to make the sound a little deeper and less raspy. From what I have found online on various other forums, this age-old debate really doesn't have a definitive answer. It seems most people agree that if your going forced induction you should definitely go with a 3in system. However, if you are under ~463hp or so a 2.5in setup is "good enough".

As of now, I do not have any plans to go forced induction and would like to stay NA with a CAI, cat-back exhaust (possibly headers in the future), and a tune. Also, it appears that a 2.5in system is the way to go if you are going to lower the car but I am still debating lowering the car or not due to all of the hills here in PA. It seems that one of the biggest debates on this matter is with the larger diameter exhaust reducing flow/back-pressure causing the car to lose power if the car does not have enough hp as is. Being right around 400hp or so I know the 2.5in system will be "good enough" but I would also like to know if anyone has experienced additional drone or a deeper exhaust tone with a wider exhaust (although most people probably wouldn't notice a difference unless compared back to back with the same exact exhaust brand and of course variations in the dyno results when comparing which setup produces more hp.).

I am not too worried about the price difference in the two as long as the system sounds good I am happy. Also, I remember someone on here saying that a wider exhaust will also increase the weight of the car of course but I imagine it wouldn't be a substantial difference. Please let me know what everyone thinks on this matter and if the (hopefully) deeper tone of a 3in exhaust would justify the price difference and not increase drone!

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[Poppacapp]

I know this has been discussed before and I have researched this topic for over an hour now and am still debating between a 2.5in or 3in exhaust. I currently have a 2.5in Borla Atak awaiting shipment due to it being back ordered and I am considering switching to the 3in version. I am looking to put on an H-pipe with this system as I already have the H-pipe and hope to make the sound a little deeper and less raspy. From what I have found online on various other forums, this age-old debate really doesn't have a definitive answer. It seems most people agree that if your going forced induction you should definitely go with a 3in system. However, if you are under ~463hp or so a 2.5in setup is "good enough".

As of now, I do not have any plans to go forced induction and would like to stay NA with a CAI, cat-back exhaust (possibly headers in the future), and a tune. Also, it appears that a 2.5in system is the way to go if you are going to lower the car but I am still debating lowering the car or not due to all of the hills here in PA. It seems that one of the biggest debates on this matter is with the larger diameter exhaust reducing flow/back-pressure causing the car to lose power if the car does not have enough hp as is. Being right around 400hp or so I know the 2.5in system will be "good enough" but I would also like to know if anyone has experienced additional drone or a deeper exhaust tone with a wider exhaust (although most people probably wouldn't notice a difference unless compared back to back with the same exact exhaust brand and of course variations in the dyno results when comparing which setup produces more hp.).

I am not too worried about the price difference in the two as long as the system sounds good I am happy. Also, I remember someone on here saying that a wider exhaust will also increase the weight of the car of course but I imagine it wouldn't be a substantial difference. Please let me know what everyone thinks on this matter and if the (hopefully) deeper tone of a 3in exhaust would justify the price difference and not increase drone!

I have the Stainless Works 3" H-pipe catback. I have noticed no power loss that I can tell. You won't get gains worth noting with a catback.. a few hp maybe, if that.

 

[2015 Silver GT]

Where did you order from that has it on back order? It seems everyone has them in stock now.

 

[nrothaar]

I have the Stainless Works 3" H-pipe catback. I have noticed no power loss that I can tell. You won't get gains worth noting with a catback.. a few hp maybe, if that.

That's a good point. Guess this would only really apply if headers were installed.

 

[nrothaar]

Where did you order from that has it on back order? It seems everyone has them in stock now.

Ordered from Hypermotive. Not in a big hurry though since I'm still waiting on my 2016 to be built :frusty:

 

[beefcake]

Where did you order from that has it on back order? It seems everyone has them in stock now.

I have a couple of atak , 1 atak black tip, and a few s types in stock with same day shipping,

and phenomenal pricing!

 

[BrantMcE]

I don't think it matters unless you plan on adding headers (like you said), since even if you go with the 3" setup, the piping before your cat back will be the restricting factor. But if you do choose to stick with the 2.5" cat back, and you upgrade to long tube headers, the restriction will be the 2.5" piping of your cat back as the long tube headers I've seen utilize 3" pipe.

 

[OppoLock]

I know this has been discussed before and I have researched this topic for over an hour now and am still debating between a 2.5in or 3in exhaust. I currently have a 2.5in Borla Atak awaiting shipment due to it being back ordered and I am considering switching to the 3in version. I am looking to put on an H-pipe with this system as I already have the H-pipe and hope to make the sound a little deeper and less raspy. From what I have found online on various other forums, this age-old debate really doesn't have a definitive answer. It seems most people agree that if your going forced induction you should definitely go with a 3in system. However, if you are under ~463hp or so a 2.5in setup is "good enough".

As of now, I do not have any plans to go forced induction and would like to stay NA with a CAI, cat-back exhaust (possibly headers in the future), and a tune. Also, it appears that a 2.5in system is the way to go if you are going to lower the car but I am still debating lowering the car or not due to all of the hills here in PA. It seems that one of the biggest debates on this matter is with the larger diameter exhaust reducing flow/back-pressure causing the car to lose power if the car does not have enough hp as is. Being right around 400hp or so I know the 2.5in system will be "good enough" but I would also like to know if anyone has experienced additional drone or a deeper exhaust tone with a wider exhaust (although most people probably wouldn't notice a difference unless compared back to back with the same exact exhaust brand and of course variations in the dyno results when comparing which setup produces more hp.).

I am not too worried about the price difference in the two as long as the system sounds good I am happy. Also, I remember someone on here saying that a wider exhaust will also increase the weight of the car of course but I imagine it wouldn't be a substantial difference. Please let me know what everyone thinks on this matter and if the (hopefully) deeper tone of a 3in exhaust would justify the price difference and not increase drone!

It's actually 462hp.

 

[nrothaar]

I don't think it matters unless you plan on adding headers (like you said), since even if you go with the 3" setup, the piping before your cat back will be the restricting factor. But if you do choose to stick with the 2.5" cat back, and you upgrade to long tube headers, the restriction will be the 2.5" piping of your cat back as the long tube headers I've seen utilize 3" pipe.

Very good point, thanks for the reply I appreciate it. Guess it really comes down to headers then. Even on a NA car probably won't notice that much of a difference

 

[nrothaar]

It's actually 462hp.

This. My whole life has been a lie:hitcomputer:

 

[stang9779]

I went 3" as most of the catback systems only come in 3". Plus you have option in the future for headers with this setup.

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