47-55.1 LS Swap Muffler Kits for AD Trucks

[JDarby]

All I'm closing in on powder coating my frame and was wondering if before I do if it makes sense to tack in all my exhaust system before doing so?

With a C4 Corvette Suspension grafted onto my frame I will have to dump my exhaust just before or after the rear tires best I can figure and am open to thoughts before I finalize any layout.

And speaking of layouts is there any place I can check into that shows options in that arena / different layouts for our AD trucks?

As always thanks for your thoughts.
JDarby

One more thing, I have been entertaining a switch with open headers
thoughts?

[leegreen]

I put a OEM full size Silverado muffler into my LS swapped DD Sonoma, mainly as it was cheap and easy to obtain. I love how quite it is, quieter than the 2.2 was. so I'd consider a Y pipe and single exhaust, gives you only one tailpipe to snake back, outside the frame perhaps.
Unless you want loud, then those dumps will work for you, and you probably wont need cutouts.

I'd only consider adding cutouts setup as muffler bypass where the cutout dumps back into tailpipe after the muffler. cutouts with turn downs always seem to sound like a handful of bad exhaust leaks

my 2 cents

[dsraven]

AD's don't have a lot of room so I am also on the single exhaust, Y pipe, train. use a larger than stock pipe if you need to, but if you're just cruising around and not hitting the track or street racing then a stock Y pipe and single exhaust will do you just fine. upgrade the muffler for a better tone if needed but, personally, I prefer a truck that is quiet rather than a truck I don't wanna go further than the local coffee shop because the thing is just so darn loud in the cab I can't stand it. I have a fairly loud crusier bike that looks cool, sounds cool, but is so loud after an hour of driving that I wear ear plugs on long trips. sorry, I must be getting old, but i also wanna be able to hear my family and those grandkids when there are group get togethers.I find nobody wants to include the "deaf guy" who always says "heh?". pretty soon you are on the outside looking in.
it's your truck, so you decide, but an exhaust that dumps out ahead of the rear axle, under the truck, is gonna rust everything from the exhaust outlet back due to oxides of nitrogen and other acidic gases given off by the exhaust gasses.an exhaust that dumps out the side of the truck ahead of the rear tires is also gonna leave a mess on the side of the truck. in my opinion, it is best to run the exhaust out to the rear of the truck. dump it out the back or dump it out the side. run the pipes on the inside of the frame if possible but if not then run the pipe outside of the frame and then back in behing the rear axle and then out the rear from there.
just my 2 cents, not worth much. but something to think about maybe. what do you wanna do with the truck? be the guy doing big burnouts and having the loudest truck in the parking lot? but then not really wanting to spend much time actually driving it? or be the guy with the cool truck that people see driving it all over the place and people will wanna go for drive and enjoy it and be able to talk while driving? or the guy who has the cool truck but nobody wants to get in it more than once.

[mr48chev]

Exhaust needs to exit out past the body of the vehicle, Worst case in front of the rear wheels, best case any where past the rear axle where it gets out from under the vehicle.

Back in the Super car hayday when turbos and turn downs right in front of the rear axle were all the rage I rode for about 30 miles each way with a buddy with a big block Mopar with that setup, I had a screaming headache for two days after that and turned down offers for rides in it after that and his gal friend dumped him because she couldn't stand the noise.

If you are just going to rip around town a half hour at a time it is probably livable but if you figure on road trips up or down I 35 to Austin or San Antonio or OK City the other way the droan will wear you out. Worse yet, your passenger of choice will hate it.

As far as mufflers of choice, there is a huge difference between seriously loud and sounds fantastic. That part is entirely about the sound you like or the lack of noise if that works. The older I get the less noise I want to hear going down the road and I have some long road trips planned.

[mr48chev]

Just thinking, you did ask about "kit" Although I did work in a Midas shop for a while doing my own exhaust is one thing that don't usually try unless it is OEM exhaust with made for the application over the counter parts. It might be a pain to get the truck or chassis to a muffler shop but you have some great custom exhaust shops in the greater DFW area that can do high quality work. I'd find out who has the reputation for doing the level of work you want and just flat have them do it.

[e015475]

I'm closing in on powder coating my frame and was wondering if before I do if it makes sense to tack in all my exhaust system before doing so?

I've tried the 'donut' style exhaust hangers that require the support rod be welded to the chassis (kinda OEM style) and I prefer the Walker 36516 style. I attach them with 1/4" or 5/16" bolts to the chassis and weld the rod to the exhaust pipe.

With a C4 Corvette Suspension grafted onto my frame I will have to dump my exhaust just before or after the rear tires best I can figure and am open to thoughts before I finalize any layout.

I have a Jag IRS in my '49(similar but not C4) and the exhaust runs all the way back to the end of the truck. The exhaust runs under the differential, then two 90s for about 2' between the bed and the frame. (the idea was to use that 2' for a resonator if I needed it) At ride height, my truck has about a beer can of clearance between the running board and the pavement and it has never rubbed the exhaust. Here's a pic of the exhaust system under the bed-



Here is the exhaust system where it runs under the differential (supported by Walker hangers)



Mine uses some cheap Thrush 'turbo' mufflers and I don't seem to need a resonator since there's no perceptible drone. Here's a pic of the exhaust system (upside down) before installation into the truck,



The turn-downs at the rear of the truck are just a polished stainless mandrel Ubend cut in half






One more thing, I have been entertaining a switch with open headers
thoughts?[

Not a fan of exhaust cutouts - just my opinion, but they're a lot of fussiness for no real power gain and likely to attract unwanted attention, especially from LEOs. Again, just my opinion but the best sounding LS exhaust is headers through an x-pipe into some Spintechs or Magnaflows followed with as small a resonator as possible to keep the drone down at cruise.

For packaging and ease of removal I put an H-pipe in mine. It's ok, it just isn't an x-pipe

[notsolo]

No help on the exhaust routing. But a glass bed cover would high light the artfull construct under this beauty.

[leegreen]

And weld on V Band clamps! Use enough Vband clamps that you can get the exhaust off without cutting it. Don't waste time with the cheaper flat band clamps.

I've DIY'd a few systems with one of those universal boxes of mandrel bends you can get now. If you like to weld and grind it is not so hard, but I wont be posting any pictures after the beautiful system e015475 posted. Puts mine to shame.

[e015475]

Originally Posted by notsolo

No help on the exhaust routing. But a glass bed cover would high light the artfull construct under this beauty.

Too late -already paved it over with oak planks

[notsolo]

Originally Posted by e015475

Too late -already paved it over with oak planks

Well if your going to cover it, might as well go with some spectacular boards and chrome strips polished to a mirror finish. Great choice..Cheers.

[e015475]

Originally Posted by notsolo

Well if your going to cover it, might as well go with some spectacular boards and chrome strips polished to a mirror finish. Great choice..Cheers.

Thanks for the nice words. It is a bed kit from MarK with stainless runners. I put multiple coats of grain filler on it then automotive clear. Cut and buffed same as the paint. Bed is suitable for hauling lawn chairs to Cars and Coffee but that's about it.

Seeing videos on how to add a Helmholtz resonator to exhaust systems and claiming excellent results on eliminating droning. Looks interesting

https://www.youtube.com/watch?v=7B90eBdLYn8

[PhilnTX]

Originally Posted by notsolo

No help on the exhaust routing. But a glass bed cover would high light the artfull construct under this beauty.

I agree!

[LS short box]

Haven't built a truck like yours or anything with a C4 suspenion but I have built most of the exhaust systems from scratch for my LS swaps using bends from Summit and straight sections from a local muffler shop.
I used to use the wider band clamps but have gone away to 1" wide band clamps like the OEM's use.
Far from apples to apples but if you go single exhaust on my 98 Wrangler LS swapped I fabbed the exhaust front to back. 2.5" tube from the left side of the engine to the right side into a 2:1 a with a 3" exit. Then 3" all the way to the bumper. Biggest Dyno Max turbo muffler I could fit.
Just a pic.
Just a question on a stock Corvette. How did they route the exhaust thru the batwing? to get it to the bumper?

[dsraven]

I hate drone on any vehicle. short hauls or long runs. I will be using a big, high flow muffler that is as quiet as I can find.
there was a fella a few doors down from me who had a nice looking almost new camaro with an expensive aftermarket exhaust kit. when he would start it up and it sounded like a tomato can attached where the muffler shouldda been. when he drove away it sounded like the most gutless wonder around. it was an automatic so when it shifter the sound changed to mimic a honda 90 under the hood. not very appealing for sure. even my wife would laugh saying he shouldda spent more on the exhaust or got a bigger engine. lol.
point is do some research on what the exhaust note usually is with a certain size of pipe and muffler. a larger pipe diameter can actually flow less than a smaller pipe. there are pulses in the pipe as the engine runs and these cause high and low pressure waves as they travel down the pipe. the low pressure behind a pulse can actually draw the next following wave like a vacuum cleaner if the pipe isn't too big to make the pulsing action less intense inside the pipe. it's a thing, google it
a modular set up is nice if you plan to work on the truck yourself. things to look for when building are staying away from heat sensitive things like starters, fuel tanks, transmissions, differentials and floor boards. using a heat shield where you can't help but be close. stay as high as possible with the piping to eliminate the chance of dragging the exhaust over a speed bump, make sure nothing will drag if you blow a tire etc. try your hardest to exit away from body panels and try to get as far back as possible to eliminate the corrosion that exhaust gasses can start. always check for leaks after an install. I use a sthethoscope with an open tube on the end because it lets you know right away if there is a leak, both by sound and by hearing the air whoosh past the tube.

[R&B51]

JDarby
From looking at images online of the C4 suspension and muffler routing, it looks like they take them right underneath the differential in the center and you can run them out the back however you want. Were you going to locate your gas tank behind that rear assembly?
If not, that may be a way to get them out the rear end.
Those Corvettes had a lot shorter wheels and tires than your truck should have especially if you’re using larger rims. That will raise the bottom of that differential even farther off the road and give you more ground clearance between mufflers and pavement.
If it helps to save you space up ahead, you might check out the muffler from Borla:
BORLA 400286 ProXS Universal Performance Muffler
I looked a long time and purchased that one for mine. It will be located right under the front of the bed in the center. It has two inlet, two outlet and a built-in X pipe in the middle. It is pretty much a flow through muffler, but if you read the reviews, people seem to really like it. some of them even complained it was a little bit too quiet for them, but got them a nice rowdy sound when they jump on it. No drone.
I have not started mine yet, but I like the way it looks, guaranteed for life, American made. Since it’s only one muffler for both exhaust pipes, the cost to me is very reasonable for all you get. I’m excited to hear it run.
Don’t know if this input will help you but wishing you good luck.

[Hot Pursuit]

I plan to use C4 suspension on my 48. I also plan to use C7 Z06 Corvette mufflers on mine. The exhaust will run under the rear diff with the mufflers behind the axle. This will require me to have the gas tank in front of the rear axle. I'm still in the planning and mock up stages but this is the direction I hope to go. Cool thing about the C7 Z06 mufflers is they have the butterfly valve which I plan to hook up to a "mild to wild" switch.