Hi! How to quiet those side pipes?

[patrickt]

Looks like if you want the Stainless Specialties "turbo tones" Cobra sidepipes that, IMO, make the pipes on a big block "just right" for anything short of full out racing, you're going to drop about $2,500. Stainless Steel Cobra Pipes You can hear mine by clicking at the bottom of my sig line.

[Don]

" Is there a way to keep the side pipes (love the way they look) but dramatically cut down that exhaust noise without killing horsepower? "

If your personal desire is to have " dramatically " quieter side pipes, and accept a loss of HP which will not impact for your style of driving , the pipes will need to be rebuilt using options such as more restrictive mufflers, cones, discs with or without the center pipe being blocked, and other options such as the internal baffles used on a Harley exhaust.

The challenge being there is no magic formula to predetermine the end result. My Z06 with Bassani X pipe and Borla Stingers is loud, but exiting at the rear makes it more acceptable when driving as compared to the location of the side pipes.

[lovehamr]

Originally Posted by shilpa

But i don't really like wearing them. It doesnt feel natural.

You're doing it wrong!

[patrickt]

Originally Posted by lovehamr

You're doing it wrong!

I don't think it looks cool either.

[shilpa]

LOL Lovehamr!

ParickT - mine are a bit smaller than those... I use the ones I plug into my ears. Although I do use those at my shooting range... ;-)


OK, so has anyone ever put up fake side pipes (not connected) and run a normal exhaust with mufflers out the back and hidden it under the car so no one sees it?

I know I'm getting goofy with ideas. But I was curious if anyone tried it...

That way I could keep my HP by going with a better quality large volume muffler and keep the cool look of the side pipes.

Let the tongue lashings begin... (except you, Lovehamr. You keep your tongue where I can see it!)

-OR-

Even better.... Both connected. And a valve or something that would allow me to switch between the two... Truly best of both worlds...

[Dimis]

Originally Posted by shilpa

LOL Lovehamr!


OK, so has anyone ever put up fake side pipes (not connected) and run a normal exhaust with mufflers out the back and hidden it under the car so no one sees it?

Happens in Aus every day... We are restricted by our Design Rules and can't* legally run active side pipes.

* - there are exceptions

Feel free to do a search - there should be numerous threads on this I'd suggest.

[patrickt]

Of course cars with real sidepipes snicker, laugh, and point their tires at cars with fake sidepipes. They don't let them play any of the Cobra games either.

[mpanten]

Originally Posted by shilpa

Ike and Mpanton - do you have a web site to get those inserts? I wanna check them out.

Thanks everyone. I Already got earplugs. I use them when i go to track days with my buddies. But i don't really like wearing them. It doesnt feel natural. Ok for the track, but I wouldn't like using them on the open road.

you can get them from here Patriot Exhaust Muffler Inserts - JEGS

I honestly am not an expert on them but the guy who had the car originally said he actually picked up hp after installing them. I can tell you that the sound level is just about perfect, you dont need earplugs when driving but they sill sould really good when wot. I like loud pipes but dont want to wear earplugs or have the cops hassle me. I belive you just take out the packing and weld these in but im not sure.

[shilpa]

Originally Posted by Dimis

Happens in Aus every day... We are restricted by our Design Rules and can't* legally run active side pipes.

* - there are exceptions

Will putting a good "normal" exhaust/muffler setup to the back allow the engine to breath as much (or almost as much) as the side pipes? I would imagine a really good set up would allow the engine to breath just fine....

If I could build a car with "fake" side pipes and a super quiet rear exhaust system I would be very happy...

[Dwight]

I replaced my 2 1/2" x 24" Lone Star sidepipes with the louvers turned backward so as to not pick up air flowing pass them, for Classic 3" x 28" with the louvers turned to pick up air flow. I also moved (rotated) the tips up 15 degrees so the exhaust would not "hit" the ground beside the car. It now blows more of across the pavement.

I gained hp on the dyno and it's a lot quieter. I can talk to my passenger at 70 mph with easy. I could not do that before.
I still have that deep rumble that a Cobra should have. And when I go full throttle, you can hear me.
I have the best of all worlds.

Dwight

[Dimis]

Originally Posted by shilpa

Will putting a good "normal" exhaust/muffler setup to the back allow the engine to breath as much (or almost as much) as the side pipes? I would imagine a really good set up would allow the engine to breath just fine....

If I could build a car with "fake" side pipes and a super quiet rear exhaust system I would be very happy...

You'll find that a cross flow system under car exhaust can actually produce an increase in HP as opposed to side pipes.
At least this seems to be the majority of anecdotal experiences of most who have done it.

I for one think that there are advantages of under car exhausts, including no snake bite & noise, but I still prefer a 427 with them pipes (active or otherwise), it adds to the look & attitude of the car

Have search on the Australian forum of Clubcobra.

[CobraV8]

Originally Posted by shilpa

Will putting a good "normal" exhaust/muffler setup to the back allow the engine to breath as much (or almost as much) as the side pipes? I would imagine a really good set up would allow the engine to breath just fine....

You are correct, it is possible to build an exhaust system that won't cost you horsepower and still gets the car to a legal sound level.

A rough rule of thumb is you need about 2.2cfm of muffler airflow for every engine hp. Dynomax has cfm ratings for their mufflers on their homepage: http://www.dynomax.com/assets/2008ca...superturbo.pdf

Place the muffler as far away from the engine as possible. This will allow the exhaust gases to cool down what actually decreases their volumetric flow rate because the density changes with temperature.

You should also try to follow the guidelines for pressure wave tuning as outlined here (one of the best articles about exhaust design I know): Auto Exhaust Science

[Voyager]

I’m curious what people are considering loud enough to require ear plugs. My KC 408 running through Superformance headers and side pipes doesn’t seem overly loud (unless I’m hammering it).

Either mine’s a tad on the quiet side or maybe I’m already going deaf?

[YerDugliness]

Originally Posted by mtpockets

Try earplugs, I wear them all the time now. Not so much for the exhaust note but for the wind noise.

Originally Posted by SunDude

Wear earplugs. I do.

That way the Cobra sounds as it should, and I save my hearing.

Originally Posted by shilpa

ParickT - mine are a bit smaller than those... I use the ones I plug into my ears. Although I do use those at my shooting range... ;-)

Agreed....although I think you'll find that the "in-the-ear" plugs are less effective than the "ear-muff" style that Patrick shows. I use the ear-muff style, they eliminate the "chuffing" from the wind buffeting my ears as well as the "chuffing" from my slip-fit exhaust, and I REALLY like the way they change the tone of the sidepipes to a lower, more gutsy tone. People laugh at me when they see me, but I just smile and wave. I have a noise induced hearing loss from driving a tractor as a young man and I MUST protect what hearing I have left (I'm a musician), so sometimes I even combine the muff-type hearing protectors with the in-the-ear type....it all depends on whether the ears are already "ringing" with tinnitus from the previous night's noise exposure or not.

Originally Posted by Dimis

You'll find that a cross flow system under car exhaust can actually produce an increase in HP as opposed to side pipes.
At least this seems to be the majority of anecdotal experiences of most who have done it.

I for one think that there are advantages of under car exhausts, including no snake bite & noise, but I still prefer a 427 with them pipes (active or otherwise), it adds to the look & attitude of the car

Agreed, again. IMHO, the 427 body style really NEEDs the sidepipes to complete "...the look". The 289 body style, not so much, and I really think the "street" models (routinely don't have hood scoops or side-exit exhausts, whether 289 or 427 style) with under-car exhausts are SO CLASSY!!

I could see a cross-flow under car exhaust system being very doable....shorty headers (maybe Mustang 5.0 GT factory style) and aluminized exhaust tubing, using very thin mufflers with ovalized pipe under the car to increase ground clearance...OR, chambered ovalized pipe with NO mufflers. The under-car/rear exhaust, if designed to be free-flowing enough to retain the majority of the horsepower, really seems to be the best of both worlds, IMHO. They sound good, look classy, and you can actually hear the empassioned pleas emanating from the sweet, young thing in the seat next to you as she sobs and begs for you to slow down !

Cheers from Dugly

[2FastCobra]

Add a turbo, the car will not be as loud and you will have a few hundred extra HP.