I Changed My Exhaust Agian . I Have Grotts Lt Headers With 3" True Duals That Dump At The Axle With Series 10 Flowmasters And Dumps. The Dumps Point Straight Down . Would It Help If They Were Angled? I Have To Do Something It Is Almost Unbearable At Low Rpm. Thanks For Any Help

 

To get rid of that noise you are going to have to go exhaust out the rear of the car.....when you dump them before the axle it is too close to the cabin and resonates badly.

True Dual cars sound really good but I couldn't take the noise daily.

 

Add a couple of bullets. That'll kill most of the drone without costing you much volume and it won't cost you a bit of performance.

 

drone and rasp are two completely different things. Colonel your remedy would get rid of rasp really well, but drone, there is no way around it with flowmaster. i know with the 40 series flowmaster mufflers if you cut them open and run water into the chambers, you will see it makes a whirl pool effect in the second chamber. i did this test just for ***** and giggles on my own set of flowmaster 40 series mufflers and what i deduced was the air was swirling and getting stuck whirling against the metal walls, and this made a resonation. kind of like when you lick your finger and run it across the lip of a crystal glass and it hums...my thinking is that the way flowmaster positions their chambers, a similar effect happens, just this time in a closed metal box...so you end up with that horrifying humming drone.

to get rid of drone you simply do a !flowmaster mod. they sound great, till the dreaded 1800-2100 rpm cruise at quarter throttle, which either leads to hearing loss, a head ache and or nausea.

 

Something that will help is to point the tips at a 45* angle TOWARDS each other...so they would be point toward the center of the car. So basically, just take your tips that are pointing down now, and rotate them 45*.

This will cause a cancellation effect of some of the sound. I would explain how it works but I'm not all that great at explaining physics...I just know it works.

I believe it was PSJ who tried this on his car with good results.

 

Thanks for the suggestions keep them coming and what is the flowmaster mod mentioned above

 

!flowmaster means to remove and throw out those flowmaster mufflers and get something new

anything with an ! before it means to get rid of it such as:

!cats
!DRL
!airbags

etc

 

haha yeah man i was just ragging on ya. only way to get rid of the "flowmaster "drone is to get rid of the flow masters. its something you learn to live with if you have their mufflers. Id suggest perhaps sweet chamber mufflers maybe they would have less drone? i've never used them so i dunno. but with dumps, its goin to resonate inside the car like a bitch. even turning the turn downs at eachother or out to a side or directly down, doesnt matter its still gonna vibrate the car. if you dont mind weight, why not use some dynomat throughout the car? or some time of insulation. that might help you out some.

 

would turning them 45* towards eachother make it quieter? or just cancel drone? what about 45* away from eachother toward outside the car? does that help?

 

I have my tips pointed about 45* towards the center of the vehicle and I don't get much drone until about 2800rpm.

 

If you cant afford to pay the guy to do it, then you will never get that exhaust fixed.

 

so no one has went from straight turndowns to angled turndowns that can compare the two?

 

I have some turndowns that I can rotate to any angle I want.

I have tried:

Straight down
Straight out the sides of the car
Straight towards each other

Never tried towards each other at a 45* angle though. Regardless, the 3 previous methods did nothing to change the drone/rasp.

Dope

 

I would recommend cats to get rid of the drone, but that will cause a loss in hps.

 

the loss in horses would be negligible with high flow cats. IF you get the right ones. magnaflow carsound cats seem to flow quite well. However with flowmasters, i definately know atleast with mustangs, it wont get rid of the rasp. It could be different with the one chambers though, it might be worth a shot. Flowmaster mufflers just seem to have a habit of making that annoying humming/drone sound at a particular set of rpms. No matter what you do, from my experience all the remedies do is change the rpm range of the drone. have you tried dynomat under teh car where the mufflers are? or there is this insulator stuff at home depot, a member on this board used this stuff on a majority of his car under the carpet and he claimed it got rid of most of the interior resonance. I'll do a search to see if i can find it for you.
T

 

I cannot find the post but the guy that did it I think his ls1tech name is DV8. Do a search for him or pm him.

 

If you guys figure anything out that gets rid of that aside from ditching the flows definitely post it. that 1800-2100 drone is awful...esp with the windows up on long trips. I have to change the way I drive (either speed or go really slow) just to avoid it. Two of my friends have my exact same exhaust setup, and it does seem that pointing the turndowns out the sides of the car helps as opposed to straight down, but its not enough to really matter. If I could get away with a small bit of dynamat that would cure the problem that would be great...otherwise Im about ready to change mufflers.

 

Its the flows, my loudmouth resonates barely at all compared to my old flowmaster that was only 1/2 as loud

 

i have dynomax ultra flows. they sounf 100 times better that the flows and no drone. Don't be scared when u look at them though. yes they are straight through but they are no louder

 

Thats your opinion. Post a sound clip and let me play judge to that.