2 1/2 or 3in

[purple ss]

Hi, l have a VZ ss stock at the moment, but going to put a bigger cam and do the heads up later on would like to no which one would be
better.What would be the best size headers 1 3/4 or 1 7/8 and the cat back 2 1/2 or 3 in thanks.

 

[Farlap]

Down to preference really...you could handle 1 7/8 & a 3" with those mods, I went 1 7/8 & 2.5" with a cam, did a lot of research/asking and 3" doesn't provide much/if any power gains un less you go forced induction...its just for sound. After hearing a few 3" LS powered cars drive past work I chose the smaller cat back...3" is stupid loud.

 

[bozodos]

been asked quite a few times before, fairly subjective really, 3" sounds better, will gain more top end power without losing any bottom end (on 6.0+ at least), not too bad in a manual, pretty loud on an auto

 

[one_and_only2004]

My motor with a cam made 325kw with a 2.5 twin and tri-y extractors, same motor and cam made 329kw with 3 twin and 4 into 1 extractors and lost a fair whack of torque down low

 

[Marty_59]

Hi There,
Mine is stock as a rock (06 SS crewman), put a 3 inch cat back system on, don't intend to do anything else at the moment, sounds good, a bit "droney", nothing I can't live with, just living the dream.

 

[Cava454]

Making 295 with a twin 2.25 into single 3 inch.

 

[Munz]

Down to preference really...you could handle 1 7/8 & a 3" with those mods, I went 1 7/8 & 2.5" with a cam, did a lot of research/asking and 3" doesn't provide much/if any power gains un less you go forced induction...its just for sound. After hearing a few 3" LS powered cars drive past work I chose the smaller cat back...3" is stupid loud.

I pretty much agree with this post apart from the stupid loud part.

Cammed LS motor with a twin 3in is where its at.......