Quietest muffler for tummy tuck and mid-arm?

toximus said:
The question also is will that cause scavenging issues? Especially if I ever sequence the header.
Click to expand...
The old mopar Hemi's had to run a muffler and a second muffler which was like a glass pack and they called it a resonator. That got rid of a terrible drone that echoed in those cars. 2 mufflers should not be much of a problem for our low RPM applications. Its not like we are leaving the line at 8K+
 
I've done some research and it sounds like 95% of the aftermarket cats are junk and won't last long. Here's a good thread which actually explains a lot of the "faulty cat" pictures in Amazon and Summit reviews: https://forums.vwvortex.com/showthr...-metal-cat&p=58187633&viewfull=1#post58187633

Looking at the OEM TJ cats they are tri-lobe too.

I can't find any replacement tri-lobes commonly available however. :/
 
astjp2 said:
The old mopar Hemi's had to run a muffler and a second muffler which was like a glass pack and they called it a resonator. That got rid of a terrible drone that echoed in those cars. 2 mufflers should not be much of a problem for our low RPM applications. Its not like we are leaving the line at 8K+
Click to expand...

Geez. There's a lot of science to this.
 
  • Like
Reactions: astjp2
In the old days, when they built headers, they would mark on each pipe and run the engine at temp, speed and load, where the mark melted from the temp pen, that is where they installed the collector. then they would install an H pipe in a special location to increase torque between the 2 banks of cylinders.
1577160382802.png


this exhaust was attached to these manifolds

1577160431055.png

or these monstrosities, which are mid 60's cast iron manifolds. Kicked ass in Nascar

1577160509972.png

1577160565125.png


This was the most radical of any of the race cars of the day, starts with a cast Iron flange and individual pipes brazed to them and then equal length pipes to a wild collector and dump system. These now cost about 10K-25K for a system if you can find one.

1577160780523.png
 
astjp2 said:
In the old days, when they built headers, they would mark on each pipe and run the engine at temp, speed and load, where the mark melted from the temp pen, that is where they installed the collector. then they would install an H pipe in a special location to increase torque between the 2 banks of cylinders.
View attachment 130652

this exhaust was attached to these manifolds

View attachment 130653
or these monstrosities, which are mid 60's cast iron manifolds. Kicked ass in Nascar

View attachment 130654
View attachment 130655

This was the most radical of any of the race cars of the day, starts with a cast Iron flange and individual pipes brazed to them and then equal length pipes to a wild collector and dump system. These now cost about 10K-25K for a system if you can find one.

View attachment 130656
Click to expand...

That might be pushing it with the tummy tuck but I'll still ask the exhaust shop for that and show them the pics. :ROFLMAO:
 
  • Haha
Reactions: taylormade73
wow, that's a lot of pipes to try and tuck under a TJ.

so what would you do? come off each cat with a slightly smaller tube and then H them together, then into a collector, then vent that out.
you could wrap 2 smaller pipes around the oil pan and H the pipes, i doubt you could find the separation to back bend the H (if that matters). the collector would need to sit inline b4 the main cat right between the oil pan and frame and that MA CA bracket. then what, into 1 larger pipe and out through the main cat and muffler, or try to carry twin pipes out with smaller cats and mufflers?
the H pipe and the vent pipe are 90* off the collector too, would it loose value or fail to share adequate pressure with the H if the vent was inline? would you have room to elbow out the vent?
seems like a lot to stuff in there. i'm interested in the solution/answer for this 1.
 
Those are race systems, and just examples of how radical things can get and how tight it can be to work with. I would just run a muffler with a second one if need be.

I will have to do the same thing on my 68 charger when I get that far. It has a 572 Hemi. I hope to drive the car someday before I die. I bought the car when I was 18, I am now almost 40 and have never driven it.
 
toximus said:
I've done some research and it sounds like 95% of the aftermarket cats are junk and won't last long. Here's a good thread which actually explains a lot of the "faulty cat" pictures in Amazon and Summit reviews: https://forums.vwvortex.com/showthr...-metal-cat&p=58187633&viewfull=1#post58187633

Looking at the OEM TJ cats they are tri-lobe too.

I can't find any replacement tri-lobes commonly available however. :/
Click to expand...

You can find the HJS cat's on ebay for $$$.
Nothing is forever, it will be an improvement either way. Besides, the exhaust is never really done on the Jeep, just like the suspension and tires, wheels....... ;-)
 
Update: I might have actually found the guy who'd be willing to do that exhaust setup.

It also doesn't seem like it'll be possible to fit the 2nd Thrush between the control arms and the axle unless things go sideways and hang low. Edit: it's possible that it'd fit a stock frame in the rear.

Also, I never realized it but the collector to the cat are 2.5". So the stock cat can stay and will help quiet things down a good deal.
 
Last edited:
toximus said:
Update: I might have actually found the guy who'd be willing to do that exhaust setup.

It also doesn't seem like it'll be possible to fit the 2nd Thrush between the control arms and the axle unless things go sideways and hang low.

Also, I never realized it but the collector to the cat are 2.5". So the stock cat can stay and will help quiet things down a good deal.
Click to expand...
Most Cat's are a straight through with the honeycomb that acts as an expansion chamber.
 
Just got home from hours of hauling over ice... I'm so dead tired but I did do a quick joy ride. I'll update my build thread tomorrow with my initial thoughts.
 
  • Like
Reactions: xxdabroxx
Have you put the skid and rear stiffener back in place with the muffler?
 
muffler looks nice and high. hows the UCA? that appears tight from that pic angle.
 
Top Bottom
Back