my exhaust sounds amazing except between 2600-3000rpm range. It makes this horrible loud raspy noise. it started about a month after i had everything installed

my setup = JVT 4-2-1 header, flowmonster cat, ebay resonator, OBX evo style muffler.

alot of people have been saying its the cheap resonator?

also it only makes this noise if you quickly accelerate through this range. if you accelerate like a grandma then it wont happen.

can anyone shed some light on the situation?

thanks in advance.

 

Sounds like you just happened to find a resonant frequency that your exhaust doesn't muffle.

One solution would be to record the exhaust note in that RPM range when it drones, measure the actual frequency of the exhaust (easy on a computer with the recording), and add a resonator that specifically cancels out that frequency. Basically, add a tuned Helmholtz resonator. (Sorry, I'm a geek, but that would be a very effective solution.)

If you don't want to go through that effort, replace existing resonator with a more effective one.

 

I know someone that has a similar exhaust setup minus the resonator but his muffler sounds like that too, i dont think those evo mufflers sound to great specially on a gsr if thats what you have.

 

i would love to try that if you could kinda explain more how to lol.

if you thinks its too complicated then could you tell me whats a good resonator?

 

really? my friend has almost the same setup as me except the header and res. and the muffler sounds amazing on his. mine sounded exactly the same until about a month. plus he got a 05 civic, idk if that would to much of a difference, would it?

 

It involves a ton of math.

Essentially, a sealed tube (or other shape) will cancel out sound in a fixed frequency, determined by its length/volume (and temp of gas inside, but we can ignore that). You determine what frequency you need to cancel, and add a sealed chamber of the correct volume to do so.

Additionally, the location of the existing resonator on the exhaust will change how it operates. It could be too close to the collector of the exhaust manifold, or too far. Unfortunately, there isn't an easy way to play around with its location to find the optimal location.

A good resonator isn't something I could identify by brand or visual inspection. I would just use the longest one that can fit (more chance of putting it in the optimal location that way), made by a known good brand.

 

is it a loud raspy noise, or does it sound like an exhaust leak type or loud rattling noise? I've had both issues in the past. When I had the resonator removed from my b-pipe, my exhaust got really raspy mid throttle during acceleration....put a resonator back on and all the raspy-nes went away. Also, I had a loud buzzing metal on metal noise during acceleration and deceleration...turned out to be the bolts to my test pipe to my header were slightly loose. Just had to do a qtr turn more with the wrench and it was gone!

 

I'm having the sme problem on my gsr but, the only problem that I have is that all bolts are intact and the car is bone stock...it makes a vibrating noise coming from the engine and I can feel the vibrations from the clutch pedal and a bit from my shifter. I also replaced my rear mount with a type r mount and it still makes a noise.

 

its a oud raspy noise. same thing as you, mid throttle.

i think i have an exhuast leak where the header and cat connect too. an exhuast leak would sound like air coming out of somewhere right?

 

It may be a cheap resonator, but like some one said, your exhast can be tuned for sound. Get your physics book out and it will delge formulas for Fr or Resonant Frequency regaurding tube size, length, and power of noise. Remember that there are harmonics which is just the current frequency producing multiples of that frequency which can be cancelled through careful computation. Have fun!

If there is a hole patch it w/ a welder.
If you don't have a welder, just buy one and start practicing.(Assuming you have the money)