Another Exhaust Thread :)

[vex]

So I'm doing research on exhausts (I need to alter/change mine) and came across this. Might prove worthwhile to those thinking about changing their own.

Consequently I'm looking at changing my exhaust by removing the y-pipe (my exhaust is not stock) and inserting a single inlet dual outlet chambered muffler to two large offset inlet outlet circular mufflers in the stock location. This should prove interesting

http://www.pontiacstreetperformance....p/exhaust.html
http://www.pontiacstreetperformance..../exhaust2.html

Although those deal with piston engined cars, their information is still nice to have.

Furthermore anyone who has experience with exhausts please feel free to post.

[RETed]

Chambered mufflers are a waste of time if you're looking for performance.


-Ted

[vex]

Originally Posted by RETed

Chambered mufflers are a waste of time if you're looking for performance.


-Ted

In my case performance has to take a back seat to daily ability/what won't get me in trouble with LEO's.

I still aim to have around 400HP with my setup, but I would like it to be as quiet if not quieter than stock (I know I'm asking for the impossible)

[RETed]

Originally Posted by vex

I still aim to have around 400HP with my setup, but I would like it to be as quiet if not quieter than stock (I know I'm asking for the impossible)

Not going to be possible, unless we're talking about something super complicated which implies super expensive...

Ever seen a Ferrari exhaust?
It's basically one big muffler from engine to tailpipe!

Chambered mufflers choke off too much performance - you'd need to build a 600hp engine to get 400hp after choking it off with all the chambered mufflers.

You want quiet?
Just don't rev over 2,000RPM.
You thinking you can rev up to redline past law enforcement?
I doubt stock is going to prevent you from getting looks.

You own a PERFORMANCE vehicle.
It's sad that you're putting noise supression a priority over performance...


-Ted

[vex]

Originally Posted by RETed

Not going to be possible, unless we're talking about something super complicated which implies super expensive...

Not necessarily

Ever seen a Ferrari exhaust?
It's basically one big muffler from engine to tailpipe!

There's a thought!

Chambered mufflers choke off too much performance - you'd need to build a 600hp engine to get 400hp after choking it off with all the chambered mufflers.

You want quiet?
Just don't rev over 2,000RPM.
You thinking you can rev up to redline past law enforcement?

No, but there are times I can not avoid going past 2000RPM in front of a LEO (see below)

I doubt stock is going to prevent you from getting looks.

You own a PERFORMANCE vehicle.
It's sad that you're putting noise supression a priority over performance...


-Ted

It is, but I have to do what I have to do. VA is notorious when it comes to exhaust systems. I have thus far received two exhaust tickets in my lifetime in Northern Virginia. 1 was on the stock exhaust and was a "defective exhaust" never mind it was completely stock without issue, I still got a ticket. The 2 was when I was driving up hill and could not maintain 2000RPM while not impeding traffic. It most certainly is a catch 22 if you ever need an example of one.

Ted, it appears I'm getting conflicting information between you and NoDOHC. This is what he has to say in a similar thread:

The chambered muffler relies largely on acoustical wave-cancelling and is therefore very frequency specific. This is offset by selecting several or many different chamber sizes to maximize the attenuated frequencies. The wave-cancelling looks like an inductor in series and a capacitor to ground on the waveform. It resists changes in flow rate to drive a high pressure pulse which will then propagate back the pipe at a destructive phase angle. to the original sound. With several chambers, the sound can be attenuated very well. Please note that a properly-designed chambered muffler will make little to no backpressure and on a long exhaust system, they may actually decrease backpressure over a mufflerless system. Chambered mufflers rely on wave inertial energy to cancel each subsequent wave, this means that low flow rates (exhaust velocities) will hurt their attenuation performance. For this reason, it is much better to run two chambered mufflers in series than in parallel.

[RETed]

Originally Posted by vex

Ted, it appears I'm getting conflicting information between you and NoDOHC. This is what he has to say in a similar thread:

Nah, not really...

I'll put money that a perforated tube muffler will outflow any chambered muffler when it comes to performance, period.

Sure, the chambered muffler will minimize noise - that's it's primary design criteria.

I'm arguing performance versus noise suppression.

There's two ways to suppress noise from the exhaust - choke the crap out of it or "tune" by resonance.
Resonance tuning is a lost art, and does exactly what NoDOHC mentions above.
The problem is that you cannot tune the entire RPM band out - you can only quiet RPM ranges, which can sometimes be quite narrow.
So unless you find an experienced exhaust guy that knows the car's set-up, it becomes an expensive proposition of experiementing with muffler positions to get what you want.

I always say to just stuff the biggest, honkin' muffler you can affort and fit under the car to get the best suppression.


-Ted

[RotorDad]

Would like to see the results when youre done & your impressions on how it sounds.

[josh18_2k]

rotary + flowmaster = WAT

im also curious about sound lol.

[vex]

Originally Posted by josh18_2k

rotary + flowmaster = WAT

im also curious about sound lol.

Who said anything about Flowmaster?

[sen2two]

I did a lot of research a while back on mufflers. Then "tested" a few out. This is the ONLY muffler I will use from now on...


Where to buy it...

http://www.jegs.com/i/Hushpower/526/13516101/10002/-1



Info...

http://www.hushpower.com/technology.php


Here's how it looks on the car...









Your welcome.

[RETed]

I have my doubts on anything Flowmaster makes...

I don't like that Hushpower muffler because we've messed with perforated cone disrupters before...they don't work.

I still believe a perforated offset pipe muffler will outflow almost any other muffler out there while giving you the best noise supression versus performance, period.

Anything baffled impedes flow - common sense.
The Hushpower muffler articles go into a lot of bullsh*t marketing words but where's the chart with the numbers?


-Ted

[vex]

Originally Posted by sen2two

I did a lot of research a while back on mufflers. Then "tested" a few out. This is the ONLY muffler I will use from now on...


Where to buy it...

http://www.jegs.com/i/Hushpower/526/13516101/10002/-1



Info...

http://www.hushpower.com/technology.php


Here's how it looks on the car...









Your welcome.

Got an Iphone/smartphone? Got a db reader? Care to make a recording so we can get some numbers with it?

[project86]

just make it loud apex n1!

[sen2two]

I do have a smart phone. But don't have a DB reader on it. Even if i did, i dropped it enough to where the speaker barely works on it. So i wouldn't trust the sound recorder on it.

I will say this. I had a 2.5" exhaust with a resonater right after the down pipe and a 2.5" muffler. I then built this exhaust which is 3" the entire way with no resonator, and this muffler is 3" also. And this exhaust is far deeper and much quieter.

No I don't have any hard numbers with charts to prove. But out of the 20 something mufflers I had on FC's. I would choose this one any day.

[TitaniumTT]

My exhaust is pretty quiet while cruising and sounds good at WOT. I drove 3 hrs out to PA with my buddy with the windows and sunroof open and we had no trouble shooting the shit the whole way out.

Magnaflow 3" in 2x2.5" out. 2.5" cans both sides. Turbo's make good mufflers too, add another

I've got a few vids on youtube if you're interested in hearing her.