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Exhaust Decibels

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By Get EPIC,
in Engines & Forced Induction

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R31Nismoid Grand Master

R31Nismoid

Posted
Posted
OK.Did the decat pipe experiment.Noticed a little increase in performance.The exhaust note was maybe 5 decibels louder but had an awesome throaty sound when on boost,absolutely loved it.Did notice how noxious the fumes were though,so after 2 days of driving i put the cat back on.I've decided instead of getting rid of the cat i'm going to get rid of the mid muffler.The kakimoto exhaust i have has the big oval muffler at the back and between that and the mid muffler i can hardly hear the exhaust!Cheers for all the input and replies fellas.
yeah mate they don't make much difference in the sound or note but the gain is probably not worth much just do one and use it for track days..

5dB is a MASSIVE amount... Its not like going from 50km/h to 55km/h - its like going from 50km/h to 250km/h

I'd be interested to know how you measured 5dB.

The muffler will cause it to be louder than a CAT removal anyhow

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Posted
5dB is a MASSIVE amount... Its not like going from 50km/h to 55km/h - its like going from 50km/h to 250km/h

I'd be interested to know how you measured 5dB.

The muffler will cause it to be louder than a CAT removal anyhow

The 5 dB was just a rough estimate.Just say for example it was 5dB, how much louder do you reckon it will be without the mid muffler?Cheers

Brezza Proficient

Brezza

Posted
Posted

i run Mines dump pipes, and a aftermarket front pipe, and 3in cat back exhaust with 1 oval muffler, and a Magnaflow 3in cat, its quiet enough not to get noticed by the cops, which is great. and it sounds pretty good at full tilt.

i had a Decat on my WRX and it was a pain with the rear bar getting dirty.

the gains arent much at all with a Decat vs a high flow cat, maybe 5-15kw at the most.

but the worst part is

Cat = LEGAL!!

DeCat = Flames out the exhaust (yes i do admit they look cool), but if the cops see = BIG FINE!!

id rather be on the safe side, cos you cant always not make your car belch a flame when you're being watched.

Brez

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Posted
  • Author
Posted
i run Mines dump pipes, and a aftermarket front pipe, and 3in cat back exhaust with 1 oval muffler, and a Magnaflow 3in cat, its quiet enough not to get noticed by the cops, which is great. and it sounds pretty good at full tilt.

i had a Decat on my WRX and it was a pain with the rear bar getting dirty.

the gains arent much at all with a Decat vs a high flow cat, maybe 5-15kw at the most.

but the worst part is

Cat = LEGAL!!

DeCat = Flames out the exhaust (yes i do admit they look cool), but if the cops see = BIG FINE!!

id rather be on the safe side, cos you cant always not make your car belch a flame when you're being watched.

Brez

thanks for the reply

thrtytwo Veteran

thrtytwo

Posted
Posted
OK.Did the decat pipe experiment.Noticed a little increase in performance.The exhaust note was maybe 5 decibels louder but had an awesome throaty sound when on boost,absolutely loved it.Did notice how noxious the fumes were though,so after 2 days of driving i put the cat back on.I've decided instead of getting rid of the cat i'm going to get rid of the mid muffler.The kakimoto exhaust i have has the big oval muffler at the back and between that and the mid muffler i can hardly hear the exhaust!Cheers for all the input and replies fellas.

i got same exhaust, nice sound. Just cant hear it when ur IN the car. swapping for a new cat back soon

_Ryan_ Grand Master

_Ryan_

Posted
Posted

my cat back is f**king loud. once i sell the stagea i will be selling it and getting a custom one made up similar to the one on the stagea using magnaflow mufflers. might just skip the mid muffler on the 32 though and put one of these on the rear http://www.magnaflow.com/02product/shopexd...ain&id=8049

stagea has this http://www.magnaflow.com/02product/shopexd...ain&id=7947 and a mild mid, catco cat and a JJR dump/front. 86db

_Ryan_ Grand Master

_Ryan_

Posted
Posted
my cat back is f**king loud. once i sell the stagea i will be selling it and getting a custom one made up similar to the one on the stagea using magnaflow mufflers. might just skip the mid muffler on the 32 though and put one of these on the rear http://www.magnaflow.com/02product/shopexd...ain&id=8050

stagea has this http://www.magnaflow.com/02product/shopexd...ain&id=7947 and a mild mid, catco cat and a JJR dump/front. 86db

fixed a link

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