My exhaust is too loud - how to make quieter?

[garry viohl]

What about using these? They have a perforated core instead louvers.

MagnaFlow 18129 - MagnaFlow Glasspack Mufflers - Overview - SummitRacing.com

MagnaFlow glasspack mufflers feature a free-flowing, straight-through, perforated core and non-fiberglass acoustic packing material. They will deliver a smooth, deep tone to your rat rod, street/strip machine, or classic musclecar. They are proudly made in the USA from 100 percent aluminized steel with precision robotic CNC welding.

[vatdevil]

Have 3 inch mufflers in use. I regret it. Should of gone with 3.5

[mickmate]

Nice David, the big difference is the seat of the pants isn't it. You're talking about a little more mellow exhaust tone with a good bass but the difference in HP is awesome. It's simple enough, more noise more power, less noise less power. It all depends what you want out of the car that has the exhaust by your ear.

[patrickt]

Originally Posted by mickmate

It all depends what you want out of the car that has the exhaust by your ear.

Which might tempt you to put a more restrictive pipe on the driver's side and a less restrictive pipe on the passenger side.

[ItBites]

The guy who said to put lower compression and a 114 lobe center cam is right (or the twin turbos...).

Mine used to be terribly loud with a 12.7:1 CR 427 and a 109 lobe center cam with a bunch of duration. I went to the bigger 540ci engine, but went down to 10.5:1 CR and a hyd roller cam with 114 lobe centers (248/252). This thing is WAY quieter (especially it got rid of the ear-piercing crack from the pipes) and runs on pump gas. I can talk at road speeds and be heard. It no longer hurts the ears.

It now runs a faster 10.6 sec quarter mile at 130mph as well...

The point is that the loudness, especially the ear piercing crack (which sounds great for a minute or so, btw) is as much the result of the compression and cam as it is the design of the exhaust. High compression and narrow lobe centers on the cam will always be hard to quiet down with sidepipes. With the great head designs we have today, there is little reason not to lower the compression and widen the cam lobes and still make a ton of power.

[CowtownCobra]

Angle the tips down 45 degrees, that way others get to enjoy the wonderful sound that you will be getting quite a bit less of (I speak from experience)

[mickmate]

I wouldn't recommend more than about 15 deg turn down.

[undy]

Originally Posted by Jeff Frigo

What was the hp diff with the chambered? Pleases explain exhaust impingement.

I gained right at 40 rwhp with the CC pipes. I also added true merge collectors that may have skewed the results a bit too.

As the exuast travels down the muffler it's constantly "bouncing' off the angular augers. Just that fact that the exhaust is repeatedly "hitting" the spiral center section creates undue back pressure, ie; impingement.

[razerwire]

Have auger insert on Bennett car and they are quiet. They cost hp, friends have said up to 50 hp. CSX car has straight glass packs and they are loud but with 10 1/2 to one compression and dynamat in doors, noise is ok from inside the car. Not meant to be funny but have twin turbos on sand car with no mufflers, its very quiet. Quiet enough that you don't need headsets to talk and you can hear turbos chirp.

[Thor maine]

If a cobra can have an under car exhaust or sidepipes,using some type of cut out system ,could you have both???Sort of quiet for just riding around or with the flick of a switch rock and roll baby!!