Jun bl downpipes sound under load

[Adamdan]

So I just got my downpipes with stock mufflers still on installed. It sounds great so far pretty much exactly what I wanted. One issue I’ve noticed at high load around 2200-2400 I get a resonance sound/almost metal vibration sound. Anyone else have this? No rattles or sounds any other time. Everything fit perfect and is solid as a rock.

 

[jraj7995]

Could be it be that the brackets aren't completely tightened down leading to the metal vibration sound? Also, do you mind doing a video of the exhaust as I was considering the Jun Bl downpipes with my bimodal exhaust but not sure how it sounds with the downpipe change alone

 

[Adamdan]

I went by the shop and put the car up and every thing is solid and the fit looks perfect. Maybe it’s just a resonance in the exhaust. As for sound it just sounds a little louder and deeper then stock. I’ll do some videos as soon as I can.

 

[NS_Stinger]

If you totally deleted your cats it could be raspiness that you’re hearing.

 

[Socalstinga]

Do you have an aftermarket exhaust? Either way, you will hit a resonance sound roughly in that rpm range. I get that with my thermal exhaust and I can only imagine it will increase exponentially once i add the DP.

 

[Adamdan]

Do you have an aftermarket exhaust? Either way, you will hit a resonance sound roughly in that rpm range. I get that with my thermal exhaust and I can only imagine it will increase exponentially once i add the DP.

I have stock exhaust just the downpipes. What does yours sound like? To me it sounds like metal vibrating to the sound in the pipes but not like there’s something loose.
You can definitely tell this car makes some drown/resenace at that rpm prob like 2300-2600 rpm. I have to be giving it enough has to make
Boost come on to make the sound any other time it does not make it.

 

[Adamdan]

Here is a video of me making it do it. It’s hard to hear it here but I can hear the sound slightly in the video.

 

[robz32]

That is normal. The sound you are hearing is the waste gate on the turbo letting all the extra exhaust gas escape without spinning the turbine.

 

[Socalstinga]

I have stock exhaust just the downpipes. What does yours sound like? To me it sounds like metal vibrating to the sound in the pipes but not like there’s something loose.
You can definitely tell this car makes some drown/resenace at that rpm prob like 2300-2600 rpm. I have to be giving it enough has to make
Boost come on to make the sound any other time it does not make it.

It’s not so much a sound per se but the obvious louder sound of an aftermarket plus vibration within the cabin. Yours sounds more “metal like” bc it’s downpipes which tend to make that sound when cats aren’t there. If you had an exhaust and no downpipe, you’d still get the resonance but it would be more of a rumble l/vibration than the metal sound you’re hearing. It’s normal for the acoustics of this car and the fact that it’s a hatchback. A few others have made this same observation on the thermal exhaust threads. Normal and the cost of doing exhaust mods

 

[Adamdan]

That is normal. The sound you are hearing is the waste gate on the turbo letting all the extra exhaust gas escape without spinning the turbine.

I noticed it happens when the turbos spools as well. Maybe it’s just making the exhaust sound raspy after the waste gate opens. It only does it in that rpm though. I can floor is after 2500 rpm and after turbos spool I do not hear it.

 

[Adamdan]

I did a lot of reading and it seems like it’s just rasp. Lots of bmw and Nissan’s with v6 get this as well. Not much I can do about it I guess. Day to day driving I don’t think I’ll hear it. I never load it up fully at 2000rpm. I don’t really hear it in 1st or second because I pass that rpm to quick it’s mostly 3-4 gear at 2300-2500. I wonder if I wrapped my downpipes if it would cover it up enough. I read of guys doing this.

 

[MattRain]

Any cons to just doing downpipes on with a Stock Exhaust, minus the sound talked about? Bit of a noob when it comes to exhaust.

 

[Adamdan]

Any cons to just doing downpipes on with a Stock Exhaust, minus the sound talked about? Bit of a noob when it comes to exhaust.

None other then that sound I hear.

 

[MattRain]

Hows the sound from the outside/back of the car?

 

[Adamdan]

Hows the sound from the outside/back of the car?

Sounds great lower tone and a little louder.

 

[MattRain]

any videos from behind?

 

[Adamdan]

I wonder if it’s wastegate rattle as well....

 

[Adamdan]

I took it to another good muffler shop that I’ve gone to lots and they had a look as well and could
Find no leaks or rattles/fitment problems. Here is another video that shows the sound better. I noticed it doesn’t the sound more when the cars cold. Also can here the sound for a split second when I shift from 1-2 at redline. Anymore ideas from you guys? I like the sound of the downpipes but this sound makes the car sound cheap when it does it.

 

[Adamdan]

Do you have an aftermarket exhaust? Either way, you will hit a resonance sound roughly in that rpm range. I get that with my thermal exhaust and I can only imagine it will increase exponentially once i add the DP.

Hey I’m just wondering what the sound you hear sounds like?

 

[Adamdan]

any videos from behind?

Here is a launch let me know what you think.