There are all these threads about exhausts sounding raspy or loud or deep or ricey etc. so i was wondering..

what factors come into play that actually make an exhaust note? Is it something in the muffler? Type of material? Etc.. please share!

 

Materials, piping(diameter, thickness), mufflers(how many, what kind, location) and obviously the engine itself plays a part in it. So basically everything. The mufflers have the most to due with tone though.

 

In the case of "straight through" perforated core mufflers and resonators, the length of the resonators (mufflers are resonators) determine the frequency that they will attenuate the most toward the lower end of the frequency range, and the diameter and spacing of the perforations in the core and sound deadening material determine the attenuation of the higher end of the frequency range. The ratio of cross sectional area between the piping and the resonator cans determine the quantity of attenuation, so it's possible to make a 4" exhaust that is much quieter than a 2". The length of the piping will play a huge role in drone. It's hard to pull everything together in a single design that will have no "bad" sound characteristics, whithout also hindering engine performance. I've built and tested at least 60 different exhaust designs this year on my S2000, and still find small improvements here and there.

 

IMO one of the biggest offender in creating a raspy/ricey is changes in diameter from the header back. I've seen guys slap on a big test pipe, then a big fart can on an otherwise stock system in between. The resulting sound made me cringe. I agree though, it's a combination of factors.

 

So examine the greddy se and why does it sound so good?

 

You mean the HKS 75mm Easily the best sounding exhaust, on any all motor I4, that I've ever heard and to top that, it's 75mm.

 

I've gone through so many exhausts, and the Greddy SE dual definately sounds the best. I am going to buy another, in fact because I miss it. I'm going to use a test pipe this time as well.

The Greddy sounds good because they used thicker piping I believe.


The HKS 75mm sounds good as well, but it is just too loud for me. Same with the Greddy SE single, sounds incredible but not to my ears while driving, lol.