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3" exhaust on R32 GTS-t

CerealKiller
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CerealKiller Veteran

CerealKiller

Posted
Posted

ok this is a different question to Waz's...

I got a 3" cat back installed on Friday (hi-flow cat, 3" piping w/ 4.5" cannon) it's damn loud...as in I don't think I'll pass the EPA dB test.

Question is, how do I make it quieter? Or should I change back to 2.5"?

The other thing is when it's idling it sounds a little lumpy. Now the car's fairly stock. The only mods I'm aware of are the ones I've done (front mount, pod). There is also a Blitz BOV. Just wondering if this lumpy sounding idle is normal or does it sound like my car had some previous work done that I'm unaware of.

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meggala Grand Master

meggala

Posted
Posted

nah cereal your car just has that crazy note from the exhaust.

its probably not that bad but you are soft :rofl:

get an exhaust shop to fit a resonator should quiten it down a bit.

but you will loose power.

so dont come back grumbling I want more power :rofl:

any way have a listen to my car that has a similar exhaust but on an sr I have no hassels with it but I dont fang it through shopping centers etc.

teh efficence of turbo all come back to how quickly you can get the exhaust out with out restriction.

vid is here http://www.meggala.com/ceffyshort.MPG

cheers

meggala

WazR32GTSt Grand Master

WazR32GTSt

Posted
Posted

this is why i was thinking of just going to a 2.5" cat-back...

how does a resonator work? is it straight-through in design like a muffler and how does it rob power?

you could just run 2 resonators if it will only lose you 5kW overall (a fair sacrifice in my opinion for ride comfort.

Roy Grand Master

Roy

Posted
Posted

Mine is pretty quiet but i am running a 3" cat, centre and rear mufflers.

I would think that throwing a centre muffler / resonator could be the answer.... my old R31 has a custom 3" exhaust with only a rear muffler and a high flow cat, and it sounded absolutley wicked, loud sure but so much better then my R32, mind you it did have a pretty on/off T3/4 as well.

Me thinks cat and two mufflers is the way to go, just make sure they are good quality straight thru mufflers and they shouldnt knock the power around too much on a car with std turbo, or slightly biiger aftermarket jobbie.

Cubes Grand Master

Cubes

Posted
Posted

Yer mines not loud at all.

With my other half driving my car normally and myself in a dunga door VN with the windows up I can't even hear my 32.

When she gives it stick I can hear it a little, when I put the windows down it is loudish but not a crude loud that is over the top. It is definately louder than some of the jap exhausts I've heard though.

I mentioned before I've got a turbo back 3", 3" cat, large center resonator and a large rear muffler.

Here's a pic of the rear muffler I am using.

muffler.gif

And another before the pipes are welded on.

200rear.gif

The resonator.. (Pics from a R33 GTR they also done)

gtrmuffs.jpg

And the Cat.

cat.gif

Chris32 Veteran

Chris32

Posted
Posted
ok this is a different question to Waz's...

I got a 3" cat back installed on Friday (hi-flow cat, 3" piping w/ 4.5" cannon) it's damn loud...as in I don't think I'll pass the EPA dB test.

Question is, how do I make it quieter? Or should I change back to 2.5"?

The other thing is when it's idling it sounds a little lumpy. Now the car's fairly stock. The only mods I'm aware of are the ones I've done (front mount, pod). There is also a Blitz BOV. Just wondering if this lumpy sounding idle is normal or does it sound like my car had some previous work done that I'm unaware of.

exhaust noise = power :)

mine is 3", race cat :) and only the rear N1 muffler, almost completley straight through - its reasonably loud, but I love the sound of it, especially under a bridge or through a tunnel. It had the centre muffler section, but this was removed due to clearence issues getting into my car park at work.

Clint32 replaced the centre muffler section with straight through 3" and tucked the exhuast closer to the chassis

Been through bretho's etc, and under idle its reasonably quiet, no cops have ever looked twice at it. I'd say it would be very close to, or over the legal limit. Sets car alarms off in car parks sometimes

I'd say if you can put up with it, stick with the 3", and maybe get a resonator put in near the diff/cradle, as that will knock a few Db from it

I am thinking of putting the centre muffler back in, on long drives it can get a bit loud, so might whack it back in.

Try a resonator, you might loose a few rwkw, but thats the trade off for a bit quieter exhaust

Chris

Sydneykid Grand Master

Sydneykid

Posted
Posted

Hi cerealeater, we always fit 2 mufflers to road cars, one around the gearbox (called a resonator by some) and one at the rear. Whether it is a 2.5", 3", 3.5" or 4" system we specify 2 mufflers, this fixes the resonance the annoying at certain rpm's. The power loss (if the mufflers used are efficient) is neglible. It's no good having an extra 20 rwkw if you can't drive the car because of the exhaust noise.

Hope that helps

WazR32GTSt Grand Master

WazR32GTSt

Posted
Posted

i think i might get mine done in 3" (already have 3" dump/front), going:

turbo-> 3"dump -> 3" front -------> 3"cat -> 3" muffler -> 3" resonator ------------------> 3" cannon muffler

all straight through in design and all the same diameter

fair trade off for the power me thinks :)

(those lines are suppost to represent the approximate distance of pipe beween each component)

wados Mentor

wados

Posted
Posted

i have a 3inch straight thru and had a 5 inch muffler and it was to loud so i went and spoke to a muffler shop and they showed me a few mufflers that they thought would do the trick so i picked one and it worked perfectly and didnt notice a drop in power, but dont ask me the brand cause i would not know.

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