2G Whats a quiet exhaust

[605jdm]

I need to find a quiet exhaust capable of 600hp but also quiet or quiet as possible.

 

[2gmitsueclipse]

Add resonators to taste to your standard aftermarket exhaust. Your down pipe will be another story.

• Care to share what your turbo setup is?
• What is the flange of the hot side?
• I assume you are running an external waste gate?
• Are you planning to recirculate it?

 

[605jdm]

Right now everything is stock but I will be going with an FP 68HTA and won't recirculate. I just need it to flow enough to be healthy for the Engine because I'm doing an electronic cutout side dump. And it's a gsx will anything get in the way of the drive shaft?

 

[605jdm]

Also from reading around it says resonators just block out certain pitches not make it all quieter?

 

[Mello]

A little off topic but a FP 68HTA will not get you your 600hp goal. At best around 500hp and this would be at the crank not wheels. The quietest exhaust is going to be stock. If you are doing a cutout you'd only be able to full boost when the cutout is open. Otherwise you'd build lots of exhaust back pressure which may cause more knock issues while the cutout's closed. If you are think on having an adjustable boost controller you could make 2 setting; for cutout open & cutout closed. Just some suggestions.

 

[605jdm]

The 600hp is just making room for the future if I decide to go hx35. And I need a high flowing exhaust so I can still boost with little back pressure. It doesn't need to be insanely quite just enough to sneak around without everyone looking. Would an electronic boost controler work? I heard they aren't reliable

 

[2gmitsueclipse]

You have much more to consider for such a build other than exhaust. I will not include the downpipe with this as you will likely not be using the typical OE style flange.

As far as quietness, You may want to go with a high-flow cat, resonator, and Varex muffler.

 

[oneslowwdsm]

The 600hp is just making room for the future if I decide to go hx35. And I need a high flowing exhaust so I can still boost with little back pressure. It doesn't need to be insanely quite just enough to sneak around without everyone looking. Would an electronic boost controler work? I heard they aren't reliable

I run an archaic HKS in cabin EBC and it controls boost very well. I turn the boost up or down with a small knob. As far as a quiet exhaust, it's going to be tough. You could add a silencer to the muffler tip and use a stock downpipe mated to an aftermarket catback.

Or your best bet might be this exhaust:

http://www.ebay.com/itm/APEXI-WS2-C...m1e65d19773:m:mY3k_RBSzH7HYf9hgRWtgyA&vxp=mtr

It's pricey so don't take my word for it if it's going to be quiet enough for you. I have heard them on other cars though and they are decently quiet.

 

[jakelandry]

This is gonna sound dumb but I made a side exit that was nothing but a 3.5" resonator for mine and it was significantly quieter than a 3" megan muffler out the rear.

 

[605jdm]

This is gonna sound dumb but I made a side exit that was nothing but a 3.5" resonator for mine and it was significantly quieter than a 3" megan muffler out the rear.

was the side exhaust all you had?

 

[JDT]

The 600hp is just making room for the future if I decide to go hx35. And I need a high flowing exhaust so I can still boost with little back pressure. It doesn't need to be insanely quite just enough to sneak around without everyone looking. Would an electronic boost controler work? I heard they aren't reliable

Assuming you mean crank horsepower an HX35 won't get you there either.

You could add a silencer to the muffler tip and use a stock downpipe mated to an aftermarket catback.

If anything he would need the opposite of this suggestion, large diameter downpipe mated to a smaller diameter catback. The closer you get to the turbine the less resistance you want in the exhaust.


Anyways,

Since you said you won't be recirculating your wastegate, get a nice manifold and a big external gate. You'll likely need something like a 4" downpipe to support that power level, so you'll have to figure that out first before worrying about the sound. Still, a high-flowing exhaust will always be louder no matter what you do. Throw on a nice muffler and call it a day.

 

[605jdm]

Just to clarify there will be a 3in electric cutout after the turbo straight out the side of the bumper and i will do my tune with it open. I just need an exhaust out the back that will be quite when it needs to be. where I live emissions aren't a big deal so most the time it will be set on side dump.

 

[ThunderChild]

mine is an SRS ebay 3" (two short resonators), turbo back, cat delete and no muffler with a 5" MBRP tip, and its about half again as loud as my buddies with a 2.5" turbo back, cat and muffler. much deeper tone, not necessarily quiet, but not screamer pipe loud.

id just get a high flow cat, one long resonator and a muffler of your choice.

since youre not gonna make the power out the rear exhaust, you dont need to worry about how much it will flow full whip really. the cutout is gonna be your bread and butter.

 

[605jdm]

Whats is a good flowing muffler?

 

[jakelandry]

was the side exhaust all you had?

Nothing but a 3inch o2 housing to a 3.5" resonator and right out the bumper. The side exit kills the hatch drone. If youre doing a cutout I would just grab a factory muffler off a car and go that route as it will be the quietest. I was just saying my side exit resonator had way less drone than a rear "race" muffler.

Also dont even bother messing with 4" exhaust. People who say you need 4" don't understand circular area scales exponentially, not linearly.

People have made 700 on 3" exhaust though its not optimal. 3.5" has 36% more area. While not accurate, for simplicity sake, that would equate to 900+ hp capable.

 

[Mello]

Unfortunately a loud one given everything is compared at equal diameter. Consider good to mean of reputable quality in construction. For me now a days I'd first look at Thermal Research for just the muffler but really I'd buy a complete setup from one of this sites supporting vendors. We have more than a few vendor's & gee whiz all of'em have some sweet looking stuff.

 

[oneslowwdsm]

Assuming you mean crank horsepower an HX35 won't get you there either.
If anything he would need the opposite of this suggestion, large diameter downpipe mated to a smaller diameter catback. The closer you get to the turbine the less resistance you want in the exhaust.
Anyways,
Since you said you won't be recirculating your wastegate, get a nice manifold and a big external gate. You'll likely need something like a 4" downpipe to support that power level, so you'll have to figure that out first before worrying about the sound. Still, a high-flowing exhaust will always be louder no matter what you do. Throw on a nice muffler and call it a day.

I only said this because no aftermarket provides anything smaller than a 3" exhaust typically and I assumed he would be running open external wastegate. I also don't see why it would matter where the restriction is, it's still a restriction but what do I know, I've only been daily driving big turbo DSMs for the last 5 years.

 

[kronus]

My suggestion is a 3" downpipe with a cutout mated to a stock cat-back.

 

[605jdm]

I think i will just buy a 3in down pipe and fab the rest i already have a muffler/tip i just need to find a long 3in resonator. does anyone know where i can find a really long 3in resonator?

 

[RyeDawg]

I just built an 3" exhaust from my Megan downpipe back. I used a resonator and a vibrant street power muffler. It's reasonably quiet at idle and awesome at wot! Check out the vibrant street power. I know you already have a muffler but it's worth a look considering their straight through . Good luck

 

[JDT]

I also don't see why it would matter where the restriction is, it's still a restriction but what do I know, I've only been daily driving big turbo DSMs for the last 5 years.

Because it's common sense. Exhaust gas at the turbine is traveling at a higher velocity than at the tip. Obviously you want to keep the exhaust diameter consistent all the way, but choking off the exhaust at the downpipe will significantly increase the backpressure compared to choking it off at the rear axle. Not to mention the amount of heat that is generated at the turbine.