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Hey guys,

Due to stupid police, I'm swapping my cat-back for the original OEM GTR cat-back. I know I will be loosing some power and agressive sound with the OEM cat-back.

What can I swap/upgrade to my setup to get back my lost power and sound? I'm thinking about getting a GLUTTED cat.

Anything else?

Thanks!

My mechanician told me about an electric valve with a Y piping, when on the track could help my performance. what do you think? is it worth 300$ ?

Nothing will give you performance back with a factory exhaust. Simple as that.

What you need to do is have a decent exhaust made/built. You can have a 3" exhaust that is legal without a drama.

Electronic valves are still illegal. So totally pointless.

What R31Nismoid said, or try and find a 3" cat back exhaust with an oval shape muffler.

That should keep the dB levels down at the same time have a better flow then stock.

Fujitsubo make decent exhaust that are quiet and still keep a very good flow.

What state are you in?

Just put the stock catback on, pass EPA/clear defect then put your aftermarket one back on

Exhausts with electronic valve control are awesome for being quiet on the street, at the end of the day they are probably illegal but if your exhaust isn’t making a loud noise then no-one is going to look at it are they?

Stock Cat is restrictive but your better off getting a highflow one

Hey guys,

Due to stupid police, I'm swapping my cat-back for the original OEM GTR cat-back. I know I will be loosing some power and agressive sound with the OEM cat-back.

What can I swap/upgrade to my setup to get back my lost power and sound? I'm thinking about getting a GLUTTED cat.

Anything else?

Thanks!

My mechanician told me about an electric valve with a Y piping, when on the track could help my performance. what do you think? is it worth 300$ ?

I'm in canada, we don't have the same rules. DB levels isn't a problem here in Canada!

You probably gonna have to tell us the whole story before we can try and help you... :ermm:

So why are you posting up about noise issues - if noise is not an issue?

I don't think he mentioned a noise issue other than losing the aggressive noise by changing.

Maybe a mounty pulled him up for too shiny?

Okay the problem in canada is that we can't swap an exhaust component that don't respect the OEM spec. 95% of the cars made are not STRAIGHT-PIPE ( or free-flow). There's so many sh*tvic out there with aftermarket racing exhaust that any police officer use a tape to measure how long his tape goes into the exhaust before hitting something. So, if his tape goes throught the whole cat-back, he will think i'm not legal because it's not normal to be straight-pipe.

I KNOW the OEM BNR cat-back is straight-pipe but these morons can't understand this fact. this is why I want to swap it for a OEM.

Sound/DB is also an issue but police officer don't have dm meter in their car to measure how loud is my GTR, so I don't care about sound because I know it's impossible to get a ticket for DB because they can't prove it.

Make sure you have good aftermarket dump pipes and good aftermarket front pipe (or sometimes called "y-pipe"), a metal type very high flow cat, then get a custom 2.75" cat-back with 2 or 3 straight-through oval mufflers. Will be quiet and will produce plenty of power over stock.

Edited by bradsm87
Make sure you have good aftermarket dump pipes and good aftermarket front pipe (or sometimes called "y-pipe"), a metal type very high flow cat, then get a custom 2.75" cat-back with 2 or 3 straight-through oval mufflers. Will be quiet and will produce plenty of power over stock.

I have a glutted OEM cat. The OEM cat-back is 3 inch and straight-through design. What kind of downpipe should I look for? any good aftermarket japanese brand?

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