The turn down and the angle of the turn down matter; they can deflect/reflect the noise right back up and under the car.
I was thinkin of putting a dog in my down pipe but then I thought that would be cruel lol
The turn down and the angle of the turn down matter; they can deflect/reflect the noise right back up and under the car.
I was thinkin of putting a dog in my down pipe but then I thought that would be cruel lol
John Laing
"The sole condition which is required in order to succeed in centralizing the supreme power in a democratic community, is to love equality, or to get men to believe you love it. Thus the science of despotism, which was once so complex is simplified, and reduced . . . . to a single principle."
-- Alexis de Tocqueville
"One of the methods used by statists to destroy capitalism consists in establishing controls that tie a given industry hand and foot, making it unable to solve its problems, then declaring that freedom has failed and stronger controls are necessary."
--Ayn Rand
"To evolve, you don't need a Constitution. All you need is a legislature and a ballot box . . . . things will evolve as much as you want. All of these changes can come about democratically; you don't need a Constitution to do that and it's not the function of a Constitution to do that."
-- Justice Antonin Scalia
This probably won't be much help, but here's the exhaust that I took off of my Shadow and modified with the muffler. I couldn't find a picture of the box with the PN that the muffler came in. All I did was cut the pipe to allow for the muffler to fit after the DP. It's not too loud at all IMO.
I have heard that the cat should be as close as possible to the turbo/head because they flow air better the hotter it is. Seems to be supported by their position on nearly every late model vehicle.
seems like the sound has alot to do with the turbo, with the garret turbo and 2.5sv its much louder than the mitisu turbo, even the straight trough mufflers don't help much in my experience, both are running 3" exhaust with no cat . maybe a chambered muffler would be a better option
The reason they position the cat as close to the engine as possible is to get the cat up to operating temperature as quick as possible to reduce cold start emissions, performance has nothing to do with it.
i had a setup on my shadow identical to the one cordes has in the pic, it was loud, really loud.
I ended up running exhaust all the way back and run a straight through muffler with no resonator and no cat, its pretty quiet.
2.5" mandrel bent all the way back with a full boar SS series muffler. The SS series muffler is just like the magnaflow but flows better and they are CHEAP, i think i paid $45 for it if i remember correctly.
The 3" made it quieter? I thought they got louder with bigger pipes.
That is crazy quiet. I have a cat and a muffler and it's way louder than that.
Originally Posted by crusty shadow
The loudest car I've had was my white Daytona with the stock exhaust sans muffler and cat. You had to wear hearing protection on the freeway because it was so loud.
My Lebaron was the same way, stock exhaust with stock muffler that all the internal baffles had rusted out of. it was only a little bit quieter than my shadow with the side dump and no muffler. Had a nice sound to it though.
Pulled the exhaust off the glhs. Now I realize the cat in downpipe thing was a pipe dream..get it, pipe dream...oh never mind.
I am moving the cat up as far as I can behind the shifter mechanism and adding a resonator right after the cat. Is going to be a crazy tight fit.
3" makes it quieter, put the muffler as far back as possible. No cat. Like John said the downturn at the end can make noise worse.
What's your current exhaust setup?
currently is 2.5" exhaust from 2.5 sv. First stop is cat, then all the way back to stratus muffler that is chambered design. That's all of it. New plan is resonator after cat if I can fit it.
Okay so exhaust is done! 2.5 dp to cat then vibrant 2.5 resonator, over the axle then to the stratus muffler. Decibels measured outside car 79db standing at muffler. Decibels in the car....90 db sitting in drivers seat...where the heck does the car find 11 db magically out of the exhaust?
That's odd.
Does the exhaust exit past the body of the car? Take a plumb bob and hold it to the car next to the exit. If the exhaust doesn't exit past that then add a short tip to it.
Tip is past the body but not past the bumper.
The muffler shop put the cat on my Voyager in the down pipe when I had them make me a 2.5 inch exhaust system. When I asked why, they showed me their book that indicated that that is where it goes on an 89 Voyager 2.5 Turbo. So far, I haven't noticed any problem with it located there. Both the cat and muffler are Magnaflow parts.
I found this high-temp cat:
Tip should be extended a few more inches, so it is at least level with the bumper, if not an inch past. That position will cause reverb off the bumper.Tip is past the body but not past the bumper. (cant delete extra photos)
Added three inches to the tip pipe. So now the big nasty chrome tip is 1" past the edge of the bumper.
The amazing part is this change, reduced the decibel reading in the car 7 db! Now sits at 83db at idle. That is one heck of a difference!
Thanks for the idea Rob!
Posting Permissions
Reply With Quote
