View Full Version : Best Quiet Exhaust. Will This Work?

06-11-2003, 02:57 AM
I want an exhaust setup that is as quiet as stock.... if possible.
i also want to delete the cats, and run 2-1/4" downtubes into a resinator(what kind of resinator, dimensions?) and then from there into a 3"(is this big eanough) single and then to a 2-1/4 y pipe and into 2 dynomax super turbo mufflers. would this be a quiet exhaust?


06-11-2003, 03:10 AM
they say the stock mufflers arent to bad i took mine off to loud put back on i got a generic resonator18.99 with 2 1/4 in 3 out then cut holes in the baffles in the rear for more flow and kept stock mufflers they say their not bad for flow sounds good not much more than stock

06-11-2003, 04:04 AM
If you want stock sound then I doubt that Dynomax muffs are gonna give you that....Like rlong said stock muffs will still flow, the biggest issue is getting rid of the resonator. NOW this is where you can go wrong and end up louder than you wanted to be. Make sure you get the 18" resonator "Magnaflow", it will make a big differance, and stick with the stock muffs maybe, or chuck up some cash and get the borla's they are suppose to be VERY quiet and expensive as well...

Good luck


XR7 Dave
06-11-2003, 11:55 PM
I went with 2.5" downpipes, no cats, a 19" long resonator dual 2.5-3.0"single underneath and then y into 2 2.25" generic turbo style mufflers. It is cheap and it is quiet. No sound inside really. Almost too quiet really. Little throaty at idle, but quiet all around.

$120 for Magnaflow resonator
$30 for both mufflers
~whatever you pay for the pipes and flanges.

06-12-2003, 12:32 AM
Here you go (http://www.public.iastate.edu/~julian/Mag%20Res%20+%20Dyna%20SuperTurbos.mp3)

Stock down tubes, Magnaflow dual 2.5" in to 1 3" out, 3" back to dual 2.5" tubes to dynamax superturbos.

It is very quite, actually quiter than I wanted, but keep in mind I have the stock downtubes and cats at the moment.

Hope this helps,

06-13-2003, 11:27 PM
I went with 2.25" downtubes w/o cats,the longest magnaflow resonator that would fit,3"centre section and dynomax hemi style mufflers angled to fit (like a late model cadillac).I find this set up to be much louder than stock at all speeds but mostly at 1800 rpm and at 2200 rpm cruise where there is some drone.If the car is sitting and I rev it in park it is fairly quiet,but it gets much louder when under load (part throttle acceleration).Nobody would mistake this for stock.I originally had the tailpipes end in the stock location but the 1800 rpm drone drove me nuts.I ended up extending the tailpipes past the bumper cover which greatly decreased the 1800 rpm drone(by about 50%).

06-14-2003, 01:22 AM
It will not be quiet without the cats.I was in the same boat as you,in that I wanted a real mellow sound with a little more rumble than stock.I tried my setup without cats to save some money first.What I have is 2 1/4 down tubes into a (large)Magnaflow polished S/S res. with 3' center section back to 2 1/2 into Borla's.Sound is as loud as an SC with stock system with just the muffs cut off,so stll a bit louder than I wanted.But sounds pretty good.So just throw in some high flow cat's.You will get flow an the car will stay quiet.

06-15-2003, 11:07 AM
Hi all!
I would just like to point out that the resonator is not just another restriction. Everybody seems to hate them, and saw them loose at first opportunity.
The primary purpose of the resonator is to "tune" the lead pipe length of your exhaust. This device improves scavenging, mostly at lower RPM's. If you were able to stand an open exhaust, cutting the pipe off right where it goes into the resonator would be the correct length of pipe for your engine (with no other high-performance mods)
As pipe diameters get larger, the length required before the resonator is reduced. I have seen many car builders (V8 stock cars) put on big-diameter tube headers and go straight to the back of the pack. Big pipes add power in high-RPM, at a cost to the bottom-end torque. A big diameter exhaust needs a resonator or crossover tube somewhere close on the downtube, or the bottom will just die.
There is nothing wrong with opening up the exhaust behind the resonator, but it should not be eliminated as the tuned length will go too high, and produce no partial vacuum in the exhaust, eliminating scavenging.
There was an article, and a nice formula in Stock Car magazine with the parameters, but I don't think I saved it. Sorry.
Have fun!

XR7 Dave
06-15-2003, 11:34 AM
the longest magnaflow resonator that would fit Just curious, how long is it? Because I have none of the issues you describe. Mostly all I hear is the soft "tick tick" from the long tube headers. :)

06-15-2003, 12:55 PM
we left all the stock stuff under the car, just gutted the cats and resonator. it very quiet. if you can weld you are set up for some serious improvements without any cash outlay. i have a manometer to hook up to see just what kind of backpressure we still have. when i get it done i will share the info. probably won't happen till next weekend.