integraxtc

iTrader: (11)

I really love the classic chambered (sweet thunders) mufflers, but they hardly muffle, lol.

I will be running Cats, in hopes of killing sound, rasp, and smell.

I was planning on going 2.5" TD's all the way back but I'm scared I'll find it too loud, as it's my DD. I will also be lowering the car.

So I've started figuring why not go 2.25" TD's (this would be after the xpipe, because I already have pacesetter lt's and 3" xpipe that came together).

What do you guys think?

Check out the chart:

A 2.25” dual system is good for a 457hp engine with zero loss…
A 2.5” dual system is good for a 513hp engine with zero loss…
A 3” dual system is good for a 812hp engine with zero loss…


My plans for the car, at least right now and for the foreseeable future, is very simple. ls1 lid, full exhaust, suspension handling mods. Trying to not spend too much more money. Start saving for real life thinngs and a vette.

96lt1m6

iTrader: (31)

I have LTs,2.5" X pipe,1ch flows,3" tailpipes would not change it for anything it is perfect!
2.25 is too small for an Lt1 or any other 350

ss.slp.ls1

iTrader: (36)

With your mods a 2.25" TD system will be more than sufficient, but I don't know what going from 3" to 2.25" would do for exhaust flow. Most kits I have seen are with 2.5" piping, which should not have a dramatic sound difference than the same exhaust with 2.25" piping.

wrd1972

iTrader: (12)

I am preparing to do 2.5" duals with chambered mufflers.

kinglt-1

iTrader: (26)

yep 2.25 piping is not going to reduce sound that much, most of the sound reduction will be in the muffler choice and cat(s).

integraxtc

iTrader: (11)

Well since you guys know more than I do, I'll just go 2.5".

1/4" won't make much ground clearance difference.

MadMike 97 Z28

iTrader: (3)

smaller pipes will actually make the exhaust louder. 3" pipes are quieter than 2.25" pipes with same muffler. so if the only reason for 2.25" is sound then I wouldn't do it. but if your doing it for ground clearance and cost then its all good.

integraxtc

iTrader: (11)

Anyone ever do 2.25" tds?

wrd1972

iTrader: (12)

I dont think anyone in their right mind would go 2.25" pipes instead of 2.50" pipes for obvious reasons. Just do the 2.50" and be done with it.

myltwon

iTrader: (1)

huh? please explain

wrd1972

iTrader: (12)

The metal mass of the pipes will absorb some resonance or sound. Smaller pipes have less mass as compared to larger. The overall amount of increased or decreased sound is very small IMHO.

myltwon

iTrader: (1)

I understand the theory, but I've yet to hear a 2.5" true dual setup sound louder than a 3" true dual setup

Greed4Speed

iTrader: (7)

Less restriction = more exhaust noise.
Larger pipe = less restriction
Larger pipe = more exhaust noise.

I don't buy into the metal mass = sound absorbtion concept. More like a larger pipe provides additional area for resonance. Go to any muffler shop and they'll tell you larger pipe = more sound. Try talking to someone through a 1.5" PVC pipe then a 2". You'll get more sound coming through the 2". The larger pipe in effect acts like a megaphone. Using your theory, the additional mass of the megaphone should decrease the sound because of absorbtion, but it doesn't. Tail pipes are the same way. The larger diameter, longer tailpipes used on trucks increases noise output.

I also disagree with the chart in the first post. I've seen engines with under 350 hp run quicker (ie more power) just by stepping up from a 2.25 to a 2.5" exhaust that supposedly supports 457 hp w/no loss. Then you also need to consider RPM band, cui, and the use of power adders. Look a deisels. They're low HP, but they require a larger exhaust than a gas engine. So no, there isn't a cut and dry "use this size if you're in a certain power level" method to choosing exhaust size.

IronOutlaw

iTrader: (4)

I had two inch pipes on my old ford bigblock with headers and it wasnt as loud without mufflers as my friends 2.5 inch pipes on his blazer with cherry bombs.

slomarao

iTrader: (6)

Id go 2.5, cat, bullets. Quiet and should make good power.

MadMike 97 Z28

iTrader: (3)

I have personally heard this before. a friend of mine had a old 55 pan head bike and the exhaust on it was a aftermarket set of i believe 2.5" straight pipes. he was going for a more old school look and swapped to much smaller pipes 1 3/4" i think (im guessing, it looked like the size of my header's primarys). and the sound was much louder and more raspy. a different friend had a 383 stroker malibu and bought the car with 2" straight pipe's with no H or X pipe and swapped them for 3" pipes with an X and the tone was much deeper but not as loud as the 2".

to me it seems to be that small pipes=louder at idle but quieter at WOT than big pipes

slick1851

True dauls will make more power than a y pipe/catback

But the trade off is there louder since most people have to run them dumped.....

bombebomb

It does not exactly take an acoustics specialist to weld up some pipe.

myltwon

iTrader: (1)

no it doesn't but weld up enough exhausts in varying sizes with similar muffler constructions/locations and you'll get a decent idea of what does what

if this were true a welded muffler in a stock catback would be louder than an aftermarket 3" catback with the same muffler, which it isn't

integraxtc

iTrader: (11)

I was considering FM merge for a custom Y pipe and either a hooker or magnaflow catback, but I want some damn classic chambered mufflers.

I'm just gonna suck it up, and give the 2.5" TD's a try (all the way back though). See how I hold up.

It's gonna be sick though!