I'm just curious if there is anybody who is really in the know who can tell me the importance that these factors play in how loud an exhaust system is.

First, obviously mufflers are made to muffle the sound, so really a car should be loudest w/o the mufflers, right?

Second, how much do headers help in producing a loud throaty exhaust sound?

Third, how much does the catalytic converter muffle the sound, and do high flow units allow more sound to get through.

Fourth, do cams change exhaust loudness and tone etc. If so, what kind of cam will give the loudest sound and deepest tone. Do you look for high or low lift on the exhaust side, or short or long durations, etc.

Any help is appreciated,

Jason

 

The biggest factor is how much air is being flowed. You can take a bone stock TBI 305 car and put a Dynomax Super Turbo catback on it, and it will be as quiet as stock. Rip out that 305 and drop in a carbed 350, and it will be MUCH louder, deeper, and throatier. Most guys who swap to carb from EFI find that the exhaust becomes louder and tougher sounding, probably due to the fact that carb cars run richer than EFI cars. Different exhausts have different tones, also. The Dynomax Super Turbo and Edelbrock mufflers have packing inside to muffle the sound, while the Flowmaster mufflers and the Hooker Aerochamber use welded metal baffles.

I went from a gutted cat to a high flow Catco cat on my car, and the sound isn't any quieter not, but it IS deeper.. the sound is better than it was, IMO it sounded like a$$ with the gutted cat. Headers tend to give the exhaust a deeper, louder, yet more refined 'rumbly' tone than stock. As far as running no muffler, I did just that and ran it for months that way. It wasn't even loud, believe it or not. I had the stock cat on there, which explains why. I'm sure it would have been obnoxious with no cat and no muffler

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91 Trans Am WS6
5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter

supposed 'peanut cammed' car (yeah, right)

MoreMoodThatMod

 

MrJ,
So by that token that the amount of air being flowed creates a louder exhaust sound, a cam that will allow more flow, along with better flowing heads etc. should produce a better exhaust note right?

And, I forgot to add above, does a true dual exhaust system that prevents cylinder sound wave cancellation be noticeably louder than a system that combines into a single pipe?

Jason

 

Jason,
Mr]is a lot more knowledgeable than me but as for a true dual exhaust I can answer that cause I have one.
It is a much deeper sound than any catback system. I always think I hear a slight "ting" sound from the catback systems, maybe its me. But as for my system much louder without the 2 cats in there, hence I keep them in there!
After I put in the ZZ9 cam from TPIS SYSTEMS the sound is much louder than before. If I travel on the highway with the windows up and air on the rumble gets to you after awhile.
So I hope it helped you.
Good Luck!

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89 IROC 350 Auto
Air Foil
TPIS Underdrive pulleys
K&N Air Filters & Mods
Modified MAF and screens removed
Ported Plenum
Edelbrock TES Headers
TRUE DUAL Exhaust
Edelbrock Performer Aluminum Heads
ZZ9 Cam
TPIS Level 5 Chip
2200 Stall Converter
2.77 Rear Gears(gotta get 3.73)

 

After I got my heads ported and polished and put the bigger cam in there I noticed a much deeper and louder exhaust. I would guess it's because a lot more air is moved trough the engine now. And I still dont have the headers on dammit! lol

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92 Z28 L98 350
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Ported and polished heads, ported stock TPI base, ported plenum, Comp Cams XR270HR-10 cam (lift .495/.502 duration 218/224 lobe separation 110), Edelbrock TES headers, LT4 valve springs, Crane AFPR, Flowmaster catback with LT1 style tips, MSD coil & wires...

"Take that auto, drop it in first, hold the brakes, stomp the gas and grin from ear to ear! :-)

 

Resinators give a very specific sound usualy it can be much deeper than a muffler, I guess you could say that they are tuned.