Hot Dog Muffler For Dropping 4Db?

[W0rp3D]

Had to get a noise test done last week, was 92 but have to be 90 or under, to pass the guy made up a 2.5" rear section with some triple flow 2.5" muffler, as soon as i passed i put the old one back on coz the 2.5 looked and sounded poo.

I was thinking about just using a hot dog just behind the cat, will this cut the db enough to make it legal, was told by a mate that an 18" one on his datsun dropped it 10db, hard to beleive since this red back 2.5 i had put on only dropped it 7 db, also will it be more of a benefit to put it in front/behind/in between the mufflers i already have?

Im looking to cut out 4-5db (or more if i can) without losing power.

[Bsa]

Decent centre muffler is what you want

[W0rp3D]

already got one, centre and rear, no jap stuff either, i asked the guy what i could do to quieten it and he said he would use the same mufflers i already have on there.

[Bsa]

You can use a hot dog but iv never had to use one need better mufflers

[GTScotT]

FYI in car audio type noise measurement (SPL), at the 90db mark every additional 3db is considered to be 'twice' as loud. So 4db is a pretty decent drop, get a muffler as a hot dog will just tone it down a little but probably still read similar.

[SargeRX8]

I always thought hot dogs are used to reduce droning, not sound levels...

My old nismo exhaust is piss quiet, it had two huge f**k off mufflers.

[Ke55pig]

We stoped 3db on a 33 with a hotdog with 3.5" exhaust

[R31Nismoid]

Highly unlikely a hotdog will get you anymore than 1-2db in a proper test.

Need a stock exhaust or a welded in silencer at the rear

[Ke55pig]

Well we read over bi bye 3 went back through and was right on just saying bye experience

[DVS JEZ]

Bi bye

[sydking]

Steel wool and a metal flange

[abr33]

I have a straight through varex with a hotdog in middle, 3 inch, 100 db open, 77 shut. magical. And my engineer signed off on it. Just dont use wot when closed or bad things will happen. that is unless you always want it quiet

[W0rp3D]

Highly unlikely a hotdog will get you anymore than 1-2db in a proper test.

Need a stock exhaust or a welded in silencer at the rear

In normal 3" form my exhaust did 92, with 2.5" pipe and muffler behind the diff it did 85, that tells me that there is ways to make it legal without needing to weld shit in and resort to using a factory exhaust, what was the phrase i saw you use the other day "smart modding" with the right bits i will get a legal exhaust that will flow the 250rwkw i have and the 300 i will get after a tune.

The hard part is making it height legal and still look good, that will be my next task.

[W0rp3D]

I have a straight through varex with a hotdog in middle, 3 inch, 100 db open, 77 shut. magical. And my engineer signed off on it. Just dont use wot when closed or bad things will happen. that is unless you always want it quiet

And if you have to do a db test they will probably tell you to change as its not allowed to be adjustable, does not matter what the engineer has signed off on.

[Ronin 09]

Brett what is your current exhaust set up - ie. centre muffler(s) / rear mufflers, diameter and length of mufflers

a big fck off centre muffler is the solution

there's some talk of Borla mufflers here

http://www.skylinesaustralia.com/forums/topic/394860-tomei-extreme-ti-cat-back-exhaust-system/

Edited March 18, 2012 by Ronin 09

[Adriano]

And if you have to do a db test they will probably tell you to change as its not allowed to be adjustable, does not matter what the engineer has signed off on.

Funny that, even though plenty of cars have variable mufflers from the factory, even taragos

[zebra]

factory fitted stuff is another world away from aftermarket

[W0rp3D]

Funny that, even though plenty of cars have variable mufflers from the factory, even taragos

Is it adjustable by the driver?

[Birds]

Get a hotdog, you'd be surprised at what they can do. My system has only the cat, a hotdog and the Varex which is effectively a straight through pipe in open mode, which nets about 100db. Surely without the hotdog it's just a straight out exhaust, which would be heaps over 100db...

I have a straight through varex with a hotdog in middle, 3 inch, 100 db open, 77 shut. magical. And my engineer signed off on it. Just dont use wot when closed or bad things will happen. that is unless you always want it quiet

Same!

And if you have to do a db test they will probably tell you to change as its not allowed to be adjustable, does not matter what the engineer has signed off on.

When I went for my test the guy said Varex probably wouldn't be legal, I said my exhaust doesn't sound that loud when it's open so if it passes on open can you clear it? He said he might be able to do that, but open came back as 100db lol. It sure didn't sound like 100db.

The legal limit is ridiculous though, the standard system is only just legal and it's quiet as shit.

[TiTAN]

In normal 3" form my exhaust did 92, with 2.5" pipe and muffler behind the diff it did 85, that tells me that there is ways to make it legal without needing to weld shit in and resort to using a factory exhaust, what was the phrase i saw you use the other day "smart modding" with the right bits i will get a legal exhaust that will flow the 250rwkw i have and the 300 i will get after a tune.

The hard part is making it height legal and still look good, that will be my next task.

16-18" x 12" x 8" rear muffler

that will get your 3" exhaust legal easily if you have a decent middle muffler.