Exhaust Neck Downs

[Cool Mr Steve]

I have a RRE 3" Downpipe and a Tsudo 3" cat-back exhaust that I need to put onto my car. Both of these parts neck down to bolt to the cat, but I'm going without my cat and I was curious... If I eliminated the neck downs (necks down to about 2.5") would it free up any noticable amount of power?

 

[Kalow]

I would, but i would also have to see a picture of the exhaust to see how involved its going to be and if you have a welder or not. You probably just paid $200 for a 3" downpipe, i wouldn't want it do neck down.

 

[Cool Mr Steve]

I'd like to hear from some people who have taken out the neck-downs. Does/will it improve performance noticably enough to make it worth my time?

 

[boostedfwdtsi]

i toke the 2.5" neck down out of my thermal cat back and ran a test pipe im not shure about perfomence but it does sound alot better

 

[Cool Mr Steve]

I'm sure my exhaust will sound nice either way, but is there anyone on here that can vouch for any worth-while performance gains attributed to this sort of modification?

 

[rowlex]

might as well do it now, rather then later.

I did it, but I did it as I installed the exhaust for the first time. here's what I did:

If it all fits on the car and bolts up real nice, take the DP and catback to an exhaust shop, have them grab a few inches of 3" pipe and slip-fit it over your exhaust you can use large exhaust clamps to seal it (or weld it, or flange it for additional cost) mine cost me 10$. I havent even put the clamps on mine yet

 

[Cool Mr Steve]

That definitely sounds like a good idea, but what I really want to hear is if there is any noticable improvements anyone has felt/heard from a modification such as this. Since it necks down to about 2.5", does that mean it can only flow/sound as well as a 2.5" exhaust system?

 

[rowlex]

On a 16g you will not feel any difference. It could be a little bit quieter but probably not much. If you have a neckdown to 2.5" consider everything up to that point a 2.5" exhaust.