Dumping exhaust down under the car

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I've been running mine that way since last summer. No regrets so far.
With a 5.9 Magnum, Doug's headers, 2.5" pipes and Jones Maxflow, the car is NOT loud. You guys with high compression will likely hear more of a noise difference in the cabin than I do.

Cutting the pipes did shave a not-insignificant amount of weight off of the car though. The pipes are hanging on the wall in the garage. I'll need to weigh them but I'd have to guess that it's 15lbs or so of dead weight off the car. :)

Sitting in traffic, the fumes are more noticeable than with the proper exit location. It's not a serious problem, IMO.
 
Ran mine that way for years. Don't know why there's an issue at car shows, are they held in dirt lots? Got pulled over one night, the cop told me I needed tailpipes. Didn't write me. I hung some fake 12" tailpipes at the bumper, no issue after that. Even had a guy at the cruise spot tell me it sounded better with the tailpipes!
LOL. funny.Here's another one.

 
Lol,.

I prefer "sleeper" mode.
You don't know I'm around till you see my tips, lol, exhaust tips .
I porbly wouldn`t ever see ur exhaust tips , just ur front end in my rear view mirror, "if" I had time to look .
 
While I got you guys attention. I also don’t want to dump underneath. I know it’s hard to get the exhaust to come out the back using 2.5“ pipes and extensions and going over the axles. Question is aren’t there smaller gas tanks that would fit that might not be as wide in order for the pipes to run along side? Don’t want to use a cell either. Anyone try it?
Sorry if I’m highjacking your post but thought it may be relevant.
 
I ran 3 inch TTi from the headers to the bumper on my 70 with stock fuel tank, 8.75 diff, no clearance issues. They are not cheap, but I believe you get what you pay for.
 
The only people who are having trouble running tail pipes are those of us with mini-tubs and big tires. Space is very hard to come by.

Since we are posting videos, here's mine on the chassis dyno with @VOETOM 's custom hand built mufflers and no tail pipes.

 
3" pipes to the rear with tubs, and inboard springs is quite common.
there are several posts with pix here.
You need to find a craftsman that WANTS to do it.
Cheers
 
While I got you guys attention. I also don’t want to dump underneath. I know it’s hard to get the exhaust to come out the back using 2.5“ pipes and extensions and going over the axles. Question is aren’t there smaller gas tanks that would fit that might not be as wide in order for the pipes to run along side? Don’t want to use a cell either. Anyone try it?
Sorry if I’m highjacking your post but thought it may be relevant.
Agree , hard to get 3 1/2" duals past a stock tank w/ offset spring hangars ! lol
 
3" pipes to the rear with tubs, and inboard springs is quite common.
there are several posts with pix here.
You need to find a craftsman that WANTS to do it.
Cheers
I forgot to mention the one year only 67 tank and that we are using mandrel bent pipe. No one around here even has a mandrel bender. We mocked up the front half of my exhaust using drier ducting and expanding foam, and then shipped those pieces out of state to be copied in stainless. You were right about one thing, you need a craftsman.
 
I forgot to mention the one year only 67 tank and that we are using mandrel bent pipe. No one around here even has a mandrel bender. We mocked up the front half of my exhaust using drier ducting and expanding foam, and then shipped those pieces out of state to be copied in stainless. You were right about one thing, you need a craftsman.

My son used pre-bent u-tubes, some cutting and fitting as best poss.
As with most first attempts, he'll do a few things a little different next time.
Your transverse tank strap should be fine as the tube sneeks out on top of the spring, below the frame, parallels the spring, then tucks back in behind the tank, to very near stock tailpipe location.
Good luck .
P.S. bend up the corner tab of the tank, .
 
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I run a couple of 24 inches red bullets with turn downs in a gutted car with no carpet and aluminum panels... and it’s not loud at all. I find it better than flow master type mufflers that seem to drone at highway speed...

FE237B67-43A3-4B60-B05E-852062CFA696.jpeg
 
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I run a couple of 24 inches red bullets with turn downs in a gutted car with no carpet and aluminum panels... and it’s not load at all. I find it better than flow master type mufflers that seem to drone at highway speed...

View attachment 1715327635
I don't run glass packs, but have never had a flowmaster that didn`t drone as t some rpm out on the hi way.
Running my 4th hotrod w/ them dumped in front of the axle , never have smelled any fumes or had a problem with them. This one is loud even w/ 4 mufflers on it ----
 
My son used pre-bent u-tubes, some cutting and fitting as best poss.
As with most first attempts, he'll do a few things a little different next time.
Your transverse tank strap should be fine as the tube sneeks out on top of the spring, below the frame, parallels the spring, then tucks back in behind the tank, to very near stock tailpipe location.
Good luck .
P.S. bend up the corner tab of the tank, .
We're thinking along the same lines. We bought a set of mandrel bent 3" tail pipes for a Nova from Pypes and we think we may be able to cut them up and have the exhaust exit behind the tire. Not exactly what I wanted but it's better than the noise I'm getting at the axle now. My tank is new but yes, it's been massaged a little here and there. Thanks for the help!
 
I've been running mine that way since last summer. No regrets so far.
With a 5.9 Magnum, Doug's headers, 2.5" pipes and Jones Maxflow, the car is NOT loud. You guys with high compression will likely hear more of a noise difference in the cabin than I do.
....

So I just wanted to amend these comments.

I got to thinking about my turn-down pipes that came out of the mufflers...and it occurred to me that these were 2.5" OD so they sat inside of the exit pipes on the mufflers...which likely introduced a bit of restriction.

So I popped the turn-down pipes out and now have mufflers pointing straight at my rear axle (not ideal obviously) but the damn thing is a bit louder and sounds better! Who knew? I'm liking the Jones Maxflow quite a bit more now.

So I'm looking for some 2.5"ID pipes to replace these...maybe this weekend. :)
 
I had mine that way for a while. The only drawback was if you get into a dusty area it blows dust up all over.

Other than that, no issues with exhaust smell here.

I have 3 1/2" with turn downs, I have never smelled the exhaust , but mine blows out pretty hard and fast . ??????? 1100 idle rpm.
 
how it sounds or if it drones, depends on the motor, gears and rest of the exhaust. my 74' is otherwise bone stock and sounds fine at any speed
 
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