True dual exhaust

[robvas]

A lot of the old engines in the 70's had an exhaust crossover in the inlet manifold to speed up the warm up process to lower emissions. If you blocked this off it totally changed the sound these old engines made. Interestingly if you fit alloy heads to these old engines the exhaust crossover is omitted.

Those heat pipes never carried exhaust though, they were just hot air radiating from the manifolds, right?

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[K4fxd]

Those heat pipes never carried exhaust though, they were just hot air radiating from the manifolds, right?

He is not talking about the flex pipe from the manifold heat cover to the air cleaner. These are openings for exhaust gas to travel into the intake manifold. EGR.
Circled in green

 

[SCP440]

If you block the cross over the engine sounds very different.. Big block Mopars loose the muscle car sound to a degree..

 

[K4fxd]

If you block the cross over the engine sounds very different.. Big block Mopars loose the muscle car sound to a degree..

I've had many Mopars and never noticed a sound change from blocking the EGR passage, but maybe. Never noticed with my Chevys or Fords either.

 

[robvas]

He is not talking about the flex pipe from the manifold heat cover to the air cleaner. These are openings for exhaust gas to travel into the intake manifold. EGR.
Circled in green

Ahh totally different thing, never saw one of those before

 

[sloww5oh]

Thanks man, I got a pair of 12” MBRP resonators and magnaflow mufflers P/N: 14419.

However if you have LTH’s I would recommend a 16” or 22” resonators to help tone that down.

You think I can emulate that sound with h pipe and mbrp resonators or vibrant? With my valved mufflers?

 

[sloww5oh]

That's pretty much what I did, added 2 vibrants in parallel at the H pipe and it doesn't sound too raspy. Ignore my friend screaming

Sounds so good, like stock tone but louder

 

[2morrow]

You think I can emulate that sound with h pipe and mbrp resonators or vibrant? With my valved mufflers?

In you case I think valved mufflers might be a good idea. It's always nice to have options

A couple from yesterday

 

[Robottrainer]

Hey guys, I know I have a thread about options for more exhaust rumble but I wanted everyone’s thoughts on a true dual setup meaning no x-pipe or h-pipe. Don’t see too many videos online, curious as to how it will sound. For context currently have custom valved system with x-pipe and Catless headers.

Whats your aversion to an x pipe or h pipe? both are pluses over nothing.

 

[Racin4ds]

The "X" and "H" pipes are to help scavenge exhaust and create better flow. They make more power than just a true dual exhaust setup, which is why almost all manufacturers went to them.

 

[Robottrainer]

Ahh totally different thing, never saw one of those before

Depending on the year, they either just flowed under the carbon to heat it, and, in some cases, bled off for the egr. Most aftermarket manifolds had this blocked off.

 

[sloww5oh]

Whats your aversion to an x pipe or h pipe? both are pluses over nothing.

Just wondering about all my options

 

[Robottrainer]

Just wondering about all my options

Back in the day that's how it was done. The H pipe increased low end torque and more of a bassy sound. X pipe is more higher rpm and raspy.

 

[Bullitt_Will]

Hi OP,

I run a true dual exhaust on my car. Long story short is that I kept breaking exhausts on track, I didn’t like the cookie cutter options available and I wanted a deeper tone devoid of all the high end rasp. (Coyotes tend to sound terrible especially at high RPM due to the 4V architecture and firing order).

I have 12” flow through resonators to delete the rasp tones and flow through Magnaflow mufflers.

When in normal street driving it is deep and mellow. When in the high RPM range it’s still throaty and not nearly as obnoxious as your run of the mill coyote.

I get a ton of compliments on the tone. Even today when I was at the track several non American car owners came over to talk about it.





Full transparency, I would consider wearing hearing protection under your helmet.

In what part of the exhaust do you have the resonators placed? Right before the mufflers or further up the exhaust? Your exhaust sounds awesome!

 

[Robottrainer]

it will not sound good from what i've read, regardless of what engine it is on. Has been tried many times. Google is your friend for examples.

That's how it used be. I believe Chrysler was the first to offer it in 63 or 64 with the max wedge and hemi cars. They found it sounded better and increased low end torque.

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