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Quiet -- stock like sound level -- turbo back exhaust

Exhaust 
78K views 149 replies 47 participants last post by  dlheman 
#1 ·
Hey guys. I have a 2016 sti, and am planning on installing a turbo back exhaust. Ideally I would install a catted DP and keep the cat back stock, as I'm happy with the sound.. But I don't want the restriction of the stock exhaust. I know it will be louder, but I want to keep the noise increase to a minimum, and definitely no drone on the hwy. Recommendations? TY.
 
#2 ·
I also wanted my car to have stock like sound, its my daily and my s2000 has a 70mm single and i need a break from that sometimes. I have the grimmspeed catted dp and hks legamax premium cat back. I would say it isn't any lounder than stock, you just hear more of the rumble. With the stock exhaust, i had some drone in the cabin during a cold start. That has been eliminated now. Eventually I will add an ELH, and from what I have read it should make it slightly quieter in the cabin.
 
#3 ·
You're not going to leave a lot of power on the table by keeping the stock catback. I use an SPT single catback with 450whp. People put melon-launchers on their cars because they like them or have a hard-on for Fast and Furious. That kind of flow really isn't needed until you're making a hell of a lot more power.
 
#4 ·
I have a catted DP. At one point a Perrin midpipe, now a Nameless Performance midpipe, both resonated. Finishing it off are stock mufflers.

It is slightly louder than stock. The 2 midpipes' sound and power are practically identical.

I also have NP 5" mufflers, but are a bit too loud so the stockers are staying. Stocker drone.
 
#7 ·
Thanks guys. Here is some more info that may be relevant.

I'm going to run a Cobb ots stage 2 map for a while. I'm not sure that will be a good idea with the stock cat back. Will it work OK?

Then, I will be doing some fueling mods and a pro tune later on, possibly as soon as this summer. Will the stock cat back flow enough to get the most out of those?

If I will need to install one anyway I'd like to do it at the same time I do the DP. And, a little louder would be fine. I just don't want something obnoxious.
 
#14 ·
I guess maybe I should have said quieter than SPT stock exhaust. I have never heard a non-SPT stock one before but my Milltek with my other mods is definitely quieter than my SPT exhaust that originally came with the car. Plus, I have the EC Approved catted version of the Milltek which is the quieter version.
 
#16 ·
Sorry, but BS. I absolutely hated the Cobb. Better than SPT, but wow, the low frequency tone this exhaust makes with a downpipe was awful. Cobb refunded me full amount, so I will saya amazing customer service.

It sounded like I had installed the subwoofer on, and let it only play 40-60 hertz.

And then when you got on it, it was quiet. Backwards of a good exhaust. It was well built though.

You should have seen the reaction of the tech when I upgraded to the Corsa.
 
#18 ·
I really liked my COBB TB pre KB ELH. It had the perfect sound for me but once I switched out the header, it started droning for me and eventually pushed me over to finding something as quiet as possible without going back to stock. I'm actually pretty happy with the sound from my Milltek.
 
#68 ·
Some examples of how my Milltek TB sounds.


Cold Start outside at 1700 rpm idle

movie


Cold Start in car at 1700 rpm idle

movie


1700 rpm idle at 30 ft away

movie

Backing out

movie

Drive by

movie

Driving around (accelerating from 15-50 mph at 3:39 mark. Pretty quiet compared to my old Cobb)

movie

More driving around (sorry, lots of traffic so couldn't really do pulls)

movie
DAMN! I wish someone did this for the cobb catback :D
 
#22 ·
OP, just keep the stock catback and go with an aftermarket catted DP. It is still going to be louder than stock with this setup but there is no exhaust out there that I know of that is as quiet as the stock exhaust.

I'm personally running the Invidia Q300 (still have the stock downpipe) because in my research it was the most quiet aftermarket exhaust I could find. I was just tired of looking at how ugly the stock mufflers/exhaust was and the Q300 hasn't disappointed in any way. It looks great, is relatively quiet, and a great value IMO (I was about to get mine for $723 shipped on Amazon). I'm sure when I go with an Invidia catted downpipe it will be even louder but right now it isn't obnoxious, doesn't drone, and I can easily carry on a conversation in my car (the car itself is still louder than the actual exhaust).
 
#24 ·
it is not quiet when trying to be quiet. lol. It's absolutely horrible driving around, especially on the highway. All you heard was a low frequency bass note.

It was flat out embarrassing to have anyone in the car. I had never been bothered by such an annoying exhaust.
 
#36 ·
Haha there seem to be such mixed opinions. The absolutes make sense (Q300 is quiet / No it's not!!), but the ones with relativity are hard to grasp (you would think everyone would agree that a certain exhaust is either louder or quieter than stock etc.)

Any advice from this crowd for people with the SPT? I like the SPT overall. I would be bugged a lot more by the supposed drone if the car itself wasn't loud as hell at highway speeds anyway. Wind noise is moderate, but tire noise is horrible on anything but brand new tires. But ultimately down the road I'm looking at a downpipe (catted Invidia or Cobb most likely) as well as ELH. Honestly I already paid so much for the SPT (yes I wanted it, but it wouldn't have mattered b.c it came on the car) I wouldn't mind spending $1000+ on something besides another catback. I don't want something loud, I just want a nice sound (as others mentioned, the SPT really only bugs me that it's so loud on cold idle and when trying to creep quietly through the neighborhood).
 
#38 ·
I had the SPT and absolutely hated the droning. So I replaced it with the Nameless mufflerless catback, which sounds epic and somehow got rid of the drone, but there's plenty of volume. If I had to do it again, I would've gone with the 5-inch mufflers to quiet the volume down. Seriously, the Nameless made me regret going through 2 Subarus with the SPT.
 
#49 ·
TheLegend,

I am interested in the Madad Whisper but their website
says "Note: We have not tested on a 2015 model yet but anticipate a few minor changes are needed. We will announce official 2015 fitment soon.".


I emailed them a few weeks ago but got no reply.


Do you have information that it fits the 15+ STI?

Dave
 
#50 ·
TheLegend,

I am interested in the Madad Whisper but their website
says "Note: We have not tested on a 2015 model yet but anticipate a few minor changes are needed. We will announce official 2015 fitment soon.".




I emailed them a few weeks ago but got no reply.


Do you have information that it fits the 15+ STI?

Dave
Don't wait on maddad that posting for 2015 testing has been up for ages, I prev had maddad and it was perfect for me and OP I'm actually tempted to buy the Gd axleback from maddad and have a custom setup welded up.
 
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