Shorter tail pipe = more noise?

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El_Freddo
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Shorter tail pipe = more noise?

Post by El_Freddo » Tue Oct 27, 2009 6:05 pm

G'day all!

Since the EJ conversion I've been keen to get a bit more of that beat out of the exhaust - on the cheap (again).

Currently I've got the old L series exhaust bolted to the back of the EJ Y pipe, I had to shorten the L's rear exhaust by an inch or two to do it. Now I'm wondering if the standard pipe after the rear muffler can simply be cut to get more of that beat note to come out of the exhaust - then to get the exhaust gases back out to the rear of the subi I was thinking of replacing the missing pipe with something larger - probabily something I can find laying around the paddock and shove on there til I get a better exhaust fitted.

Or the other option is to grab another pipe from the last joint at the diff to the rear tip, cut the (dead) muffler out and replace it with a hotdog pipe... Dunno about this one though, it was just a thought I had that may be worth playing around with.

What are your thoughts?

Cheers

Bennie
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GOD
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Post by GOD » Tue Oct 27, 2009 6:13 pm

The other day I broke off the mostly-rotten tailpipe at the back of the muffler on my wagon. Made no appreciable difference to noise.

Maybe try cutting it off at the front of the rear muffler and replacing it with a bit of straight pipe.

Dane.
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phillatdarwin
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Post by phillatdarwin » Tue Oct 27, 2009 9:16 pm

just get a striate tho muffler

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El_Freddo
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Post by El_Freddo » Tue Oct 27, 2009 9:30 pm

I might try out a second "hot dog" style muffler if I can find one in the shed. This is going to be a no money spend exercise. I'll grab the old brumby's muffler pipe to have a play with - they're the same shape over the rear half shaft of the diff :D

Cheers

Bennie
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Bumpty
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Post by Bumpty » Tue Oct 27, 2009 9:34 pm

Good idea, just muck around with any piping you have and see what you get :)

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TOONGA
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Post by TOONGA » Wed Oct 28, 2009 8:47 am

yes a shorter tailpipe will make a bigger rumble but remember the quicker gasses escape the less back pressure on the valves sometimes good sometimes really bad

have a look around at other subis that have rumble makers (motorboats as my wife calls them) notice where the exhaust tip stops, normally under the body this allows the exhaust noise to resonate under the car

a good way to go is 2.25 inch pipe into a standard cat, then a small hot dog or resonator followed by a 3 inch end tip usually with a cannon or a small V8 resonator of some sort

but yes that costs money so hunt around the wreckers as I have

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wrxer
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Post by wrxer » Wed Oct 28, 2009 11:21 am

i think the law dictates that the tail pipe must stick out the past the bodyline so that exhaust doesnt get sucked into the cabin.

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steptoe
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Post by steptoe » Wed Oct 28, 2009 12:13 pm

rules of self preservation and common sense needed here, don't go too short. I wouldna thort any noise change could occur beyond last muffler

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little_red_L
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Post by little_red_L » Wed Oct 28, 2009 4:56 pm

hi, my L has standard pipe with the rear muffler replaced with a resonator, as u suggested, from an Ef falcon (which looks like a muffler), that i got for free, and its a cracker! Cheap and easy if ur handy with a welder. sounds more 'raced out' than the classic suby sound.
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Post by FROG » Wed Oct 28, 2009 5:02 pm

Chopped my rear muffler off my ol' lib and welded on an old 323 centre box .... Sounded great for a zero dollar mod :-)
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Post by Phizinza » Tue Dec 22, 2009 6:10 pm

The length of the pipe coming out the back of the muffler doesn't do much in volume if long or short. Larger pipe will be deeper note, smaller higher. If you want louder, increase header to tail pipe size. Want a growlier note, increase header size.

I found 2.5" pipe to be to large, but I still run a 2.5" tip because now I have standard size pipe running to the back it isn't as deep as before so the extra deepness from the tip helps a little.

Standard exhaust mufflers won't do much to the noise level. They will soften off the sound though. Silencer style mufflers will make it a bit more quite, as they have baffles. Cat converters do both jobs well, softer and quieter. A exhaust with just a Cat and a straight through muffler will give a fairly beefy noise but not harsh sounding.
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shuffbag
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Post by shuffbag » Sat Jan 09, 2010 3:17 pm

my L had a 2 1/4" one "sports" muffler (not cannon) off the factory ej headers. was great but to loud, add a resonator and it was better. sounded lumpy at idle and cruzing but full throtle was :)
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