Exhaust Lesson: Resonators?
- Thread starter bajajoaquin
- Start date
O.K. Mr Guru Stan Sir. When I built the exhaust system for the Batwagon I duplicated the design of the AAR Cuda system only I did it in 2 1/2" instead of the AARs 1 7/8". 2 1/2" S.S. all the way back from the cast iron headers to the S.S. Flowmaster reverse flow 2 1/2" in and 2 1/2" out to the reverse bend and then out thru' '71 Dodge-Plymouth fluted S.S. tips. No X over, no H pipe, just 2 seperate 2 1/2" systems all the way back dumpin' fumes. How do I quiet that system down because from what I'm hearing here adding resonators up stream is pi**in' in the wind? I love sound the way it has but I can not carry on a conversation with any one riding in the beast without hollering and the AM and AM-FM-CD-cassette and the serius radio tunes were a compleat waist of $ because the decibel level of the exhaust is in the stratosphere. Those reverse flow Flowmasters worked fine for Jack Rousch and the 5 liter 'Stangs he sent down the road in the early 2000 years. I can't believe my 440 makes that much more noise the 5 liters 302s with the huffers he hung on 'um! Whatz my fix oh Guru?
commando1
Old Man with a Hat
Jer, you are the last man on Earth I would tell what to do. You forgot more than I'll ever know 
.
I'm not stupid
.I'm not stupid
My last post waz not a test my friend and you know darn well that I know you're a long way from stupid. Anybody that can draw picturez and talk that frequency and Resonance stuff iz way farther down the road then this Ole Dawg wll ever stray. I think you've learned by now I'm really just ah duck tape and coat hanger kinda redneck. Why do yeah think it took me 22 yearz to bring the Batwagon back from the brink?
bajajoaquin
Senior Member
I'll bite.
First, you said "upstream" of the mufflers. You would want to put resonators down-stream of the mufflers: between the muffler and the tailpipe.
Second, I think that larger pipes are noisier than smaller pipes. So going to a bigger size may have increased your noise level.
Third, an H-Pipe will quiet the drone by having the exhaust pulses do some cancelling of each other.
since you're not going to re-do the system with smaller pipes, I'd try the resonators mentioned above in the Minivan post and try adding an H-Pipe.
First, you said "upstream" of the mufflers. You would want to put resonators down-stream of the mufflers: between the muffler and the tailpipe.
Second, I think that larger pipes are noisier than smaller pipes. So going to a bigger size may have increased your noise level.
Third, an H-Pipe will quiet the drone by having the exhaust pulses do some cancelling of each other.
since you're not going to re-do the system with smaller pipes, I'd try the resonators mentioned above in the Minivan post and try adding an H-Pipe.
Ripinator
Old Man with a Hat
I wuz thinking the same thing.
commando1
Old Man with a Hat
My students have studied well.
I'll bet those mini van resonators are 2" inlet.
O.K. guys, but let me get you on the same page with a few high lights within my system. 1st. Please let me say that I'm well aware of the fact that resonators should be placed down stream from the mufflers but! Lets look at a few of the design limitations those suggestions incounter. Those 300J+300K cast iron headers are 2 1/2" W/ 4 bolt flanges that were manufactured to dump on the inside on the stub frame and outboard of the torsion bars and theirs less then a 5" gap there. Then they take a "Z" bend bringing them to within 3"s on either side of the drive shaft and then straight back into the reverse flow mufflers. And then back out in a gradual 165* curve to dump in front of the drive tires SANS: the AAR Cuda and Challenger TA of 1970 fame. Their is not 1 inch of straight exhaust pipe south of those mufflers and maybe 6"s of clearance to the ground. An H pipe might help just a little and is Possible but it would have to be built with flanges on the inside of both pipes and a U shaped center section just south of the tail shaft with mating flanges on both ends. And with clearance under the drive shaft we're probably down to 3"s of clearance to the ground. Their is absolutely no way to install an H pipe with much more clearance that slides both sides together and is clamped like the old 426's systems were. AND you would have to fire wrench it apart to even pull the engine. The reason I chose this system is that I picked up on it while delivering a 40,000Lb load of heads to Rouch Engineering in Lavonia, MI. and when I saw what he was doing to those '02-'03 'Stangs and realized that system was 2 1/2" like my headers my tongue got hard. The end result is that if you've ever been to a Nascar race when the big blocks were still running and you had seats next to the fence you know that it ain't just the marbles they through at yeah when they go by that hurts, the noise is just as big ah factor. And to Scrap $many K worth of exhaust to install regular pipe plus two mufflers plus two resinators and still dodge the rear axle and the foot well that exists between the rails in that 9 Passenger Wagon, WELL. Guess I'm just screwed and gonna have to live with the noise aye? I hope the new owner will understand the dilemma and can live with it too, Jer
bajajoaquin
Senior Member
Given that description, the only thing I can think of is if you can remove some of the 165* arc with some sections of straight tube and angled flanges. That might allow you to put resonators aft of the mufflers.
Otherwise, you're right: you'll have to live with the noise.
Got any pictures?
Otherwise, you're right: you'll have to live with the noise.
Got any pictures?
70bigblockdodge
Old Man with a Hat
Now your talking my language maybe a bit hoakey but the noise will be up in the air that's how I have lived with straight stacks for almost 20 years you have to hear it not me.
commando1
Old Man with a Hat
70bigblockdodge
Old Man with a Hat
WOULDN'T HAVE IT ANY OTHER WAY. First truck I bought had straight pipe, first thing I did to my second, even cut muffler off co kenworth I drove. Loud pipes save lives, even the 20 yr old airhead playing with their phone will look up.
300rag
It's Not Going to Shift Itself
Alright, whooz writin this reply and what did they do wit Jer, cuz this iz not how he soundz.
I recently went on a truck forum to find out what people's opinion was on the best cat-back system for my truck. The same sh*t on this forum too (except they wear redneck camo instead of gold chains) all say their cat-back sounds and performs the best and trashes the other cat-back systems.
commando1
Old Man with a Hat
There ya go. There is no "best".
You can't adjust the tone by pressing buttons on your $5,000.00 Harmon-Blose-Concert Hall" 23 speaker "In-cabin Entertainment Center".
Put on a set of mufflers that have a sexy name to you and leave the damn original AM radio off.
The memories of 'Thrushes" still get a rise out of me. Can't really remember what they sounded like but....
I can go home now.
You can't adjust the tone by pressing buttons on your $5,000.00 Harmon-Blose-Concert Hall" 23 speaker "In-cabin Entertainment Center".
Put on a set of mufflers that have a sexy name to you and leave the damn original AM radio off.
The memories of 'Thrushes" still get a rise out of me. Can't really remember what they sounded like but....
I can go home now.
AYE? Say what? Wanna turn the volume up ah couple clickz. I ran straight stackz on the last K100 too. Maybe that'z why thoze reverse flowz side pipez sound so good, yeah think?
70bigblockdodge
Old Man with a Hat
Yep love it, nothing like a turbo, no matter what color motor, whistling through straight stacks in the whee hours in the morning with no traffic dragging 50,000 up a small grade makes the hairs.on the back of my neck stand up, kinda like standing at the water box at the track.
commando1
Old Man with a Hat
Not even at the MPH where the govenor locks you out.
At the RPM tonal sweet spot locked in by the cruise.
At the RPM tonal sweet spot locked in by the cruise.
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