Any exhaust scientists out there?

[67-LS1]

I am putting a 2013 LFX and 6 speed auto in my 1966 Chevelle. I am nearing the point where I need to consider what to do about the exhaust system and I have a few "theoretical" questions. I am trying to get the engine to sound bigger than it is, ie, a much lower/deeper tone.
1.) Does the placement of the muffler in the system affect the sound? In other words, would there be a difference if I put the mufflers way forward, near the down tube vs just prior to the axle vs just prior to the rear bumper and tips?
2.) Does the placement of the crossover pipe affect the sound? Would running two pipes farther back prior to joining them change the tone?
3.) If I do merge the two pipes, would it sound different if I stayed with a single pipe from that point back vs splitting back to two?
4.) Has anyone ever run "true duals" without any crossover?
Any other theories about how to give a small engine a much lower tone? I am not constrained by the body because a lot of the floorboards needed to be reworked to fit the engine/transmission anyway?
Expansion chambers?
Resonators without mufflers?
Mufflers without resonators?
Wrapped tubing?
Fiberglass packed vs chambered mufflers?
Large tube vs smaller tube?
Wall thickness of the tubing?
I do plan on keeping the cats. Other than that, anything goes.
Thanks,
Dennis

[191185]

glass packs

[KMPrenger]

That fact that you can't run headers like the LLT V6 will hurt you in this area as you can make that engine sound pretty mean with headers and the right exhaust combination at idle and low - mid rpms. Up high the V6 sound will always come through.

Here would be my thoughts. These things come with 2 cats on each side....dump the 2nd cat on each side to gain a throatier sound but not need a tune to avoid the CEL light, or dump both but this causes a CEL on stock LFXs.. Weld in replacement pipe, or replace it with something like the ARH LFX "headers"(catless and will cause CEL) or the SOLO high flow cats.

Where the stock H pipe is in the stock exhaust setup, replace that with the Magnaflow resonated X muffler. This will tone down the aggressiveness of the exhaust, (less rasp) but will lower the tone as well. Otherwise if you want more rasp and want it to be louder don't add this but I'm afraid it will end up annoyingly loud and raspy. Also, from here run 2.5 or 2.75" piping. 2.5" should be good.

Out back run straight out, or try bullet style mufflers. Dynomax or Magnaflow do bullet style and I'm sure others do as well.

In my opinion this will get you a louder exhaust, with a lower tone, and hopefully a little growl, but without the crazy annoying V6 rasp that comes with systems that are non-resonated.

Good luck.

Dare I ask why you chose this engine for a classic Chevelle?

[DSX_Camaro]

Originally Posted by 67-LS1

I am putting a 2013 LFX and 6 speed auto in my 1966 Chevelle. I am nearing the point where I need to consider what to do about the exhaust system and I have a few "theoretical" questions. I am trying to get the engine to sound bigger than it is, ie, a much lower/deeper tone.
1.) Does the placement of the muffler in the system affect the sound? In other words, would there be a difference if I put the mufflers way forward, near the down tube vs just prior to the axle vs just prior to the rear bumper and tips?
No. Muffler is muffler.
2.) Does the placement of the crossover pipe affect the sound? Would running two pipes farther back prior to joining them change the tone?
No. But H pipe vs X pipe will give a different sound.
3.) If I do merge the two pipes, would it sound different if I stayed with a single pipe from that point back vs splitting back to two?
Different yes. How much, hard to say. I'm not sure what happens when you do that.
4.) Has anyone ever run "true duals" without any crossover?
It's really best to have the crossover to equalize the exhaust flow.
Any other theories about how to give a small engine a much lower tone? I am not constrained by the body because a lot of the floorboards needed to be reworked to fit the engine/transmission anyway?
Expansion chambers?
Resonators without mufflers? Smoother deep tone.
Mufflers without resonators? Raspy.
Wrapped tubing?
Fiberglass packed vs chambered mufflers?
Large tube vs smaller tube? 2.5" will sound better than 2.25". 3" is too big without forced induction.
Wall thickness of the tubing?
I do plan on keeping the cats. Other than that, anything goes. If you delete the secondary cats you'll get a better sound.
Thanks,
Dennis

Answers in bold.

[67-LS1]

I chose this engine because it is new and interesting. I did an LS1 in a 1967 Chevelle back in 1997, so just something different.
My goal now is 35 MPG. The new Camaro V6's are EPA rated at 30 MPG and I should be 1000 lbs lighter when I am done, so I feel 35 is within range.

I am not looking so much for "louder" as "deeper" or "lower" toned. I know the lack of headers eliminates the possibility of tuning the pulses to miss one another, that's kind of what made start asking the questions I did. I thought maybe some combination might be able to help minimize or eliminate the "V6" sound.

[12WhiteLS]

I found this video pretty helpful.
http://m.youtube.com/watch?v=Y0Va3sDhqwI

Seems like x pipe is the way to go unless for some reason space restricts that. On this engine I'd recommend a resonated x pipe(magnaflow and dynomax make them) to cut out some of the drone and rasp. Farther up in the exhaust the better to take advantage of scavenging effects. Mufflers are a personal preference , IMO over 4k they all sound like a DOHC V6.

[DSX_Camaro]

Originally Posted by 67-LS1

I chose this engine because it is new and interesting. I did an LS1 in a 1967 Chevelle back in 1997, so just something different.
My goal now is 35 MPG. The new Camaro V6's are EPA rated at 30 MPG and I should be 1000 lbs lighter when I am done, so I feel 35 is within range.

I am not looking so much for "louder" as "deeper" or "lower" toned. I know the lack of headers eliminates the possibility of tuning the pulses to miss one another, that's kind of what made start asking the questions I did. I thought maybe some combination might be able to help minimize or eliminate the "V6" sound.

30mpg is only in the 2LS Camaro with the 2.92 rear end gears. You could probably get there though... might need turbos and like 3.07 or 3.15 gears.

The V6 sound always shines through. At idle, though, if you use the magnaflow resonated x pipe 2.5" and run a full 2.5" system (or 3" system if you're running turbos) you'll have a great sound and a very deceiving idle.

[67-LS1]

I am running 3.07 gears and the tires are 27.6" tall so I won't have quite the gear ratio the new Camaros have, but I will be close to 1000 lbs lighter. That's huge!
I also give up some aerodynamics, but it's a goal.
I have heard that V6 engines with headers can be made to sound like a v12 by tuning all 6 tubes together. Not an option I suppose on the LFX.
What makes the Subaru WRX's sound so deep? They are not that big.

[Jason@JacFab]

Subarus do have a unique sound which can sound great with the right setup. I think the nature of engine designs radically changes the sound. For instance, a 90 degree chevy v6 can be made to sound pretty damn good, while as I have not really heard a great sounding 60 degree v6 (ly7, llt, lfx) to date. I believe the suby sound has to do with it's engine design, as the cylinder banks are basically 180 degrees apart.

I don't have a 2LS and I've gotten between 30 and 32 mpg on 100% highway road trips. I think your mpg goals may be fairly within your grasp, especially given the weight advantage.

I'm interested to know how you overcame the wiring and security stuff for the swap? Are you running the 6 speed auto as well?