turbo vs. exhaust sound

[88shadowpjct]

so i knwo having a turbo, a wide open exhaust is quieter than a N/A car. but whats the difference with the size of the turbo? bigger = quieter? or louder?

going from my mitsu int he shadow to a garrett hopefully sometime soon.
local laws are harsh on exhaust and right now its wide open 2.5" DP, to stock (i think 2.25 or 2") then to a 2.5" magnaflow in the back. so im getting the evil eye from the black and white. i'd like to put a 3" DP on the car when i get the garrett on there with a dump (they're just fun) and run a 2.5" system behind that as quiet as i can without too much restriction. i was thinking high flow magnaflow cat, good resinator, 2.5" system from FWD, my 2.5" magnaflow straight through muffler that i already have. sound like a good idea?

i wish i could get that sweet turbo spool sound out of the exhaust but its one thing or the other here i guess lol sweet flow and sound or no tickets

[crazymadbastard]

You could always get the regulations from your police dept and get a meter from radio shack and test. I think most of the db measures are from a certain distance. My car is pretty loud with a 3in sv,dp, 3in full exhaust no cat and straight through muffler- it sets off alarms. If I take it easy it is just mellow. Some say that the 2.5 is actually louder than the 3in.

[Turbo-Baron]

On my car with the mitsu and full 2.5"exhaust with high flow cat and muffler it's not that loud I hear the wicked whine of the turbo more then anything.The only time it gets pretty loud is when i down shift and get the popping.

[88shadowpjct]

well our law is that you cant modify the exhaust AT ALL.. but since no1 really knows about these cars around here, im just gonna tell the cop the high flow exhaust was part of the ES package in '88.. hopefully they'll beleive me. but other than that, i'd like to keep the noise down just so its a more comfortable ride.. thats why i want the dump... for when i want it to be supid loud

[Gutfeeling]

Sounds like a good exhaust for what you're trying to meet.

Wow I dont care what type of penalty the law would permit to give if one were to modify there exhaust.... I will say if I ever run into that law I for sure will make some waves.
I have seen exhaust systems to perform just fine while being not so noisy and keeping it clean from some aftermarket suppliers.
This is the land of the free right?

[The Popes Bro]

2.5" makes a higher pitch sound that can ring and pop worse. But mostly it has to do with pitch mostly, 3" has a nice deap sound and gives the impression that it is quieter. I also notice better sound from a bigger garret than a mitsu. Maybe the velocity effects sound? Slower velocity makes for a different sound? Or maybe it is like music, bigger horn makes a lower note? I know we've talked about 2.5" vs 3" but mot why or how yet with sound.

[Reaper1]

Definatly run a cat. It will quiet down the exhaust a good amount. I run a 3" with cat and a Borla XR-1 muffler. At idle and just cruising it's not too bad. It's defintalty louder than stock, but no louder than a stock SRT-4...possibly even quieter. If noise still too much you could try a turn-down on the end of the exhaust. It will make the ground help absorb some of the noise.

I think you'll be fine with what you have planned. The whole not being able to mod your exhaust at all in your area was argued about before. I forgot what the outcome of it all was...I know what *my* opinion is...LOL.

[moparfwdsleeper]

My CSX was running FWDP 2.5" pipes, no muffler or cat. I loved it, wasn't that loud at all, even clocking out on the stock 15PSI boost gauge.... I loved it, can't wait to hear it again!

[zach]

on mine i have a 5.9 cummins diesel turbo with 3'' all the way custom down pipe and swingvalve housing manderelbend out the driver side it's quiet yet intimidating at idle but when im tuning or rpm testing it loud enouph to set off the alam and a friggen integra 3 houses away lol but when im cruzing at 140kph (lol canada sorry) its very quiet like fallin asleep quiet

[turbokid]

Wow i have an 89 so its got the 2.5" sv and dp. The rest is 2.5 inch to the muffler. It sounds great, purrs quietly, is a bit louder then the stock exhaust but its not blarring loud. Only time its loud is when you downshift and the rpm's climb. its not the best flowing system out there but it is pretty good and you can definitely hear that turbo wind up and is way less restrictive from my stock system on my other 89 2.5 baron

[88shadowpjct]

i put a 2.5" magnaflow cat on and there is absolutely NO difference.... i figured untill i could get my exhaust and turbo n, i'd throw a cat on it... you cat even tell it has a cat. its just as loud and still pops so loud it sounds like a shotgun when i downshift.

[Reaper1]

That's strange...considering all the stuff inside a cat there SHOULD be a difference. It will only be around 3db, but that is enough that it could make the difference between being legal and not(sound wise). Also, it will help with droning on the highway.

The car will ALWAYS be loud, pop and carry on when you downshift with a free flowing exhaust. That's just the way it is. My suggestion...don't do it around cops!

[88shadowpjct]

ok what really sucks now is when i get on it, all i smell is rotten egg. aka burning cat. why would this be? running rich/lean? its brand new! i know the a/f i should get is a wideband but i dont have that kind of money right now so im going to pick up a narrow band tomorrow just to monitor it a little. that should be enough with a stock computer, injectors, regulator, pump, boost, etc. to at least show if its rich or lean right?

[tkelly27]

Yeah, you should be fine with that little light show. You'll definitely know if you're rich or lean, just not how far rich or lean you are : D

I vote for a 2.5" DP, cut out, cat, and muffler. Don't get me wrong, I love 3", but a 2.5" cut out is enough exhaust flow for a huge amount of power. One of the highest power AT DSM's did it with a FULL 2.5" exhaust system, 600-700hp at the wheels. Also, since you have a cut out for racing, you can afford to have a chambered muffler for the street. Nice and quiet.