I was told that catback I recently installed will "break in" and sound quieter and less ricey.

Will some miles on it really make much of a difference?

 

Which cat back?

 

invidia q300

 

An exhaust doesn't break in "per say". I think what the person meant is when they told you that, is that over time as you get the exhaust hot, you will start to cook the insides of the muffler. As that happens, you will notice the exhaust will become louder. I would say about 1dB or 2 louder. Nothing, you as the owner will notice, but if you ever put a new muffler beside an used muffler, you will notice the used muffler is louder.

Drive the daylights out of it. The sooner you blow the packing out, the better lol

 

Was there anything out of the blue when installing the q300?

 

Nice choice I've heard that it actually will get lauder as it gets more driven. Did you get a full cat back or is it just the axle back..??

 

Full cat back. The cold start sounds like a Maserati, That's why I am bit concern. But it quiet down after about 8 seconds. Maybe just I am not use to the new sound when I start the car every time.

 

No, did it within an hour at a shop

 

Awesome , I'm interested in hearing your thoughts and experience with the q300 as time progresses (cabin noise, low rev, high rev, idle, etc).

 

So far,2015 IS350 rwd . everything under Eco mode, audio off. Driving like grandma.
Idle : quiet ( not same quiet as stock, but you don't feel bothered at all)
High rev 3k-5k : nice throaty growl.
Low rev 1k-2.5k: making the most sound, but not reach the level that you will feel embarrassed. With ML volume at 22, you can hear just 10% of the sound inside.
Cabin noise: only noticeable between 1k - 2.5k.

Cold start : the sound will make you feel embarrassed. Sooo not Lexus lol. But good thing is will gone after few seconds.

Occasionally poping sound while decelerating. Like a cracker.

 

Thanks! Very informative post. Not so sure how I feel about the popping sound

 

It's very occasionally, I'd say 1 out of 20 times when you stop at red light. Also, it's not loud. When it happens people at sidewalk are not gonna turn around and check on you

 

Popping sound is the fuel cutoff when you let go of the gas. Its ok.

You wanna talk popping, I have 1 7/8" headers to 3" hi flow cats, to 3.5" exhaust to 3.5" mufflers, to 4" tips on my camaro. When I pop, it sounds like a gun shot. I have had people behind me hit the brakes because they thought something was happening.

 

Yep, I know what it is but I'm not sure if I want it lol but 1/20 seems like a small occurrence...

 

Its a shame you can't crack the ECU, because you can turn that off.