Evoryder

iTrader: (55)

Never fear, fat mat is here!

BluEVOIX

iTrader: (69)

Install a straight flow through widebody muffler. Most likely you have a round muffler and those are not that great for quieting exhausts. I'm not sure what the largest size that will fit, but something around 22".

roger smith

iTrader: (4)

He already has a cat-back so I don't think he wants to replace the muffler.

I'll say again, a resonator or two will do plenty. Look at Fujitsubo's exhausts. One of their quietest exhausts has a N1 style muffler like you have and two resonators I believe. That exhaust is just about as quiet as stock I think, and it has a N1 style muffler! It's the two resonators it has that does the trick.

BluEVOIX

iTrader: (69)

I'm sorry but I have to disagree with you. Fujitsubo's quietest exhaust is the one with the widebody muffler RM01 not the round N1. And Fujitsubo exhausts taper both inside the muffler and at the flange to connect to the cat.

Round mufflers simply do not have enough material to quiet the exhaust down as much as widebody. Resonators have even less material in them and dont make any significant changes like most would want them to. What resonators can do is help change the tone a little and reduce raspiness etc...

The best and only efficient way to tone an exhaust down is through a muffler. The widebody ones do the best job because they hold more sound deadening material. Also make sure its a straight flow through with no tapers or baffles for max performance.

The Cobb exhaust, RRE both use widebody mufflers and have no tapers. The RRE has 2 resonators and the Cobb has 1 small one. Removing the resonators will not make any huge sound difference as would removing the widebody muffler and replacing it with a round body.

Have you ever added a resonator?

Also another thing to consider is what is quiet to you? If I can hear it in my car then it is loud. If I can hear my car accelerate a block away, then that is loud as well. I much rather accelerate in complete silence having my tire noise over power my exhaust sound than having the best sounding exhaust system in the world. This is my opinion of quiet.

roger smith

iTrader: (4)

Yes, I agree BluEvoIX. An exhaust with an oval shaped muffler is going to quiet the exhaust the most. But our poster already has an exhaust system. I'm assuming he doesn't want to get a totally new one.

In my experience, no I've never installed a resonator to an already existing system. Currently I have a full titanium cat-back that has an oval shape muffler (no resonators). Before that I had an HKS hi-power cat-back, just about the same as the poster's. It has the N1 style muffler and a resonator. That HKS exhaust was about the same sound level as my current. Maybe a little louder from what I remember.

I went to ARC in Japan a couple years ago. They showed me their demo car with this exhaust on it.
http://www.upscaleautomotive.com/ima...edium/7508.jpg
I could not believe how quiet that exhaust was. It was so close to sounding stock or maybe even quieter. You can see that exhaust has a resonator on it. I don't know how that exhaust was so quiet.

Also check out this
http://forums.nasioc.com/forums/arch...t-1191265.html

Now I'm not expert with physics, but a resonator tapers an exhaust pipe to become wider then thinner again. The fact the exhaust pipe isn't following a straight path means that sound waves will change direction. I'm guessing the changing direction will cause the sound waves to bounce a number more times before reaching the exit. The more times a sound wave bounces off a surface the less energy it has? The same concept as echoes I believe. If you sit in a closed room and make a sound, the sound doesn't continue on forever.

BluEVOIX

iTrader: (69)

Not all oval/widebody mufflers will quiet the same. It depends on size, packing material, tapers, etc...

The fujitsubo exhausts taper inside the muffler as well not just the flanges. The Tanabe exhaust which is also quiet tapers inside the muffler to wround 2.7" (I personally measurde this by sticking something inside slowly trimming till it fit through).

Performance resonators work as follows and should not taper.

First there are 2 types. Perforated and Louvered.
http://www.roadraceengineering.com/exhaustparts.htm


For the most part its a straight flow no taper tube. The ones that might have tapers or baffles are restrictive and mostly are on factory exhausts not something people will upgrade to normally.

The sound wave passing through the exhaust tends to go through in an expanding form hitting the walls. As it moves to the pores, the some of the waves pass through the pores and get absorbed by the sound deadening material inside. Thats how the perforated (left resonator) works. The Louvered (right resonator) disrupts waves causing some to bounce back and cancel eachother out, but at the same time disrupts exhaust flow a little.

Now the point of upgrading your exhaust system is to make more power by making it less restrictive. Puting more restrictions back on sort of defeats the purpose of upgrading from stock. If you have a 3" exhaust but there is a taper of 2.5 inch inside then your basically flowing only 2.5 inches of space.

Besides if he is going to cut any part of his exhaust to make it quieter, then its better to do it right the first time. And that is through the muffler not the resonator. Unless he chooses to buy a different exhaust setup.