I was looking at the Magnaflow cat-back system and it appears that there is no resonator after the cat. Is this correct, and do I really need one? I am going to contact a local custom mandrel-bending exhaust shop to see about a custom system and need to know if I need to have a resonator quoted also.

It appears that there is a resonator on the Miltek system.

Thanks !

 

I think you need to talk to an Exhaust Engineer before diving in the deep end with a "custom" exhaust.

Most MINI cat-backs use a resonator just after the cat, btw.

 

In this picture of the Magnaflow for the MCS there is a resonator after the cat-


Of note the Borla Street has no resonator- (Borla Race has a resonator)


Supersprint doesn't have a resonator either-


Milltek has a resonator-


So do you need a resonator for your custom system? No one knows and it depends on the system you design.

What is your goal of doing a custom system? Save money? Be unique? Get more HP than an aftermarket system? Some goals are easier to attain than others.

The problem is no matter what system you design it's not likely to do any better for added power than the existing systems. You have to do the design and test it. It might even do worse than stock but you can't tell until you make it. If you make a complete system from cylinder head through exhaust header to cat-back then you might do better but it will cost too much to make it worthwhile- Ask Caddman, he's been working on that solution for a long time now.

 

Try a Moroso Spiralflow aft of the cat. Costs about $50 and made a noticeable difference in power and noise when I swapped it for the resonator. Slightly quieter and took out the very highs and lows. Significantly reduced droaning. Straight through design. Only downside is that it's not stainless. Additional advantage is that it's not polished.

 

**************

 

The only reason for looking into a "custom" exhaust is the fact the in the area I live in SS is really kind of a waste of money. Was looking to get into a lower cost system and support the locals. I can get the magnaflow SS mufflers and have the shop do the tubing. Don't need SS, aluminized should do nicely.

I am just not sure why some systems have a resonator and others don't.

 

ScottinBend, I have a Miltek without a resonator on my 05 MCS. It is a 'semi custom' one-off that Miltek built for Randy Webb. I haven't heard the standard Miltek but Randy said that mine is louder. Personally, I think it sounds great. Not as loud as the Borla Sport but much louder than stock. No drone at highway speeds.

Jeff

 

OK, you don't need SS and want to do a system for less. Certainly that is a good reason for considering a custom exhaust. Still, your results may vary- it will depend on your components and pipe diameter. Note that the diameter of various systems will vary and some will go more narrow after the mufflers. Are you doing a single sided or dual exhaust? For MCS?

Resonators are basically used with mufflers to reduce exhaust noise. See
http://www.womanmotorist.com/index.p...878/event=view
Quote:
All the components in the exhaust system are tuned, including the exhaust pipes. Mufflers and resonators are designed to quiet the sound of the engine's exhaust, which can be quite abrasive if allowed to be uncapped. The mufflers and resonators have baffles or passageways built into them for the exhaust gases to follow. Routing the gases in this manner produces a muffling effect, quieting the noise of the engine's exhaust.
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Some designs do OK without resonators while others need them- some of the dual systems with smaller mufflers have resonators- like Borla Race while the Borla street has larger mufflers and no resonator.

 

.....and the Magnaflow has no resonator. So I go with my idea of getting just the mufflers and having the exhaust built.


Cool !

 

HOW CAN YOU GO WRONG?

 

by not having a resonator
-Paul