H or x pipe, headers and true dual

[kg93]

I'm picking up a set of JBA long tubes today, no cats (do they need a o2 **** welded in?)*should I get mopar header gaskets or would I be fine with the JBA ones?

Anyway I was thinking about going true duals but I'm unsure if I should go x pipe or h pipe. Is the only true difference sound? I've heard h pipes are more muscle sounding and x is more exotic.*

Also I'm guessing I should go full 2.5" rather than 3" right?*


On another note, how much louder would straight pipes be than my Flowmaster super 10? I currently have just that and cats but its another 140 for two single super 10s.

What muffler options do I have for a DEEP muscle sound?

Ive heard headers with a cat delete don't really change the sound level

 

[Dubstep Shep]

X-Pipe almost always makes significantly more power than a H-Pipe. They tend to be raspy on cars like mustangs, but you might not even notice it on the Hemi...

H-Pipe makes less power, but tends to have a deeper sound.

There is one other option out there, and it's my personal favorite. The MAC prochamber. It made more power than either the X or H pipes in a test and the sound is just a deep and throaty as the H-Pipe. Basically it's just a X-pipe where the center X is removed and a case is put around that entire area. Pretty cool stuff.

 

[kg93]

Isn't that Mac Prochamber technically only for mustangs?

 

[14hemiexpress]

If your going true dual I would go 2.25 or 2.5 3in is way to big. I would also go h pipe and preforated mufflers like mbrp, jones or Magnaflows they will be a deeper tone x pipe and flowmasters are on the raspy end of the spectrum.

 

[sicmadek]

Jay and thad did true duals recently. Both picked up decent power gains.

 

[Dubstep Shep]

You could make a prochamber pretty easily.

 

[1morepart]

I've done lots of true duals on trucks and muscle cars. The only measurable difference between an x or h is sound- not power ! The x scavenges better, but is raspy( depending on muffler). I personally run a catless true dual h with 2 chamber flow masters ( 40 series). Don't use pipe bigger than 2.5" or run straight pipes- your motor needs some back pressure or you will lose your bottom end power, as it will shift towards the upper rpm power band. In my opinion, the 10 series sound raspy and incorrect for a hemi. Catless, h pipe, and 40 series flow masters are spot on.

 

[kg93]

thanks for all the opinions guys! made me decision even harder hahah, all these mufflers are expensive for what they are when you gotta buy two

 

[Dubstep Shep]

The straight pipe has better times on these trucks for whatever reason. Could be the y-pipe.

I will contest the point about x-pipes not making more power. I've seen multiple dyno graphs from mutiple vehicles that say otherwise.

 

[kg93]

so i did some research, from what i found, x pipe provides upper rpm range power, while h pipe helps with some torque on the bottom end. Which, correct me if im wrong but h pipe would be better for running 37-38" tires and offroading


any input on the headers? Mopar gaskets? extra **** welded in? and should i get some better header bolts?

 

[N1ck]

General consensus around these parts is mopar gaskets or bust.

 

[Dubstep Shep]

I used copper gasket sealer on the Mopar gaskets and have zero issues.

 

[14hemiexpress]

I've done lots of true duals on trucks and muscle cars. The only measurable difference between an x or h is sound- not power ! The x scavenges better, but is raspy( depending on muffler). I personally run a catless true dual h with 2 chamber flow masters ( 40 series). Don't use pipe bigger than 2.5" or run straight pipes- your motor needs some back pressure or you will lose your bottom end power, as it will shift towards the upper rpm power band. In my opinion, the 10 series sound raspy and incorrect for a hemi. Catless, h pipe, and 40 series flow masters are spot on.

Engines don't need back pressure. Back pressure actually hurts everything. The reason you lose low end power when steping up the diameter is the fact you lose scavenging. When a engine fires it does it 1 cylinder at a time causeing pulses. In a small enough diameter pipe the first pulse will actually create a vaccum Drawing out the next pulse so on a so forth. If you step up the pipe size you lose that scavageing because the pulse can bounce around in the pipe and you will lose that pull the first pulse has. On these trucks in stock form dual 2.25 works great it flows just enough to keep the good torque in low rpms. Most people that step up to dual 2.5 will report a loss in low end tq but a gain in the higher rpm as the engine pushing the exhaust out faster at higher rpm the exhuast pulses will seal up giving you the scavageing in the higher rpm creating more peak hp but a loss in low end as the exhaust pulses can bounce around in the pipe at lower rpm.

 

[Dubstep Shep]

Just remember, you lose A LOT of your scavenging effect when you don't have a crossover between the duals on a cross plane v8. The uneven cylinder firing from bank to bank has to be balanced out by combining the exhaust from both banks into an even pulse.

 

[kg93]

Engines don't need back pressure. Back pressure actually hurts everything. The reason you lose low end power when steping up the diameter is the fact you lose scavenging. When a engine fires it does it 1 cylinder at a time causeing pulses. In a small enough diameter pipe the first pulse will actually create a vaccum Drawing out the next pulse so on a so forth. If you step up the pipe size you lose that scavageing because the pulse can bounce around in the pipe and you will lose that pull the first pulse has. On these trucks in stock form dual 2.25 works great it flows just enough to keep the good torque in low rpms. Most people that step up to dual 2.5 will report a loss in low end tq but a gain in the higher rpm as the engine pushing the exhaust out faster at higher rpm the exhuast pulses will seal up giving you the scavageing in the higher rpm creating more peak hp but a loss in low end as the exhaust pulses can bounce around in the pipe at lower rpm.

so you believe i should use 2.25" after the 3" collector on the headers to keep the low end.

Im eventually going to 'try' to add a supercharger so i dont want to have to change my exhaust again.

Just remember, you lose A LOT of your scavenging effect when you don't have a crossover between the duals on a cross plane v8. The uneven cylinder firing from bank to bank has to be balanced out by combining the exhaust from both banks into an even pulse.

yeah im definitely going to use a crossover i know i need that

 

[14hemiexpress]

so you believe i should use 2.25" after the 3" collector on the headers to keep the low end.

Im eventually going to 'try' to add a supercharger so i dont want to have to change my exhaust again

Build it for your mods list I think dual 3 would be to much I think I would go with 2.5 Matt at moes would be the best person to ask he has extensive trial and error with headers and lots of knowledge with these trucks. Dual 2.5 should support between 5-600 horse. This is compairing apples to oranges but friend of mine runs dual 2.5 on his 408 Windsor making around 600 horse.


With a the headers your already going to knowtice a low end drop if your butt dyno is sensitive but you will more than make it up on the top end.

 

[14ram5.7]

Cant beat the sound of my LT headers with straight pipe all the way back with a x pipe crossover. Just cut the mufflers off yesterday

 

[Dubstep Shep]

Cant beat the sound of my LT headers with straight pipe all the way back with a x pipe crossover. Just cut the mufflers off yesterday

You got a pic of your setup? I'd love to see it

 

[14ram5.7]

I can get one for ya

 

[kg93]

post up a pic i would like to see it also.

My normal guy i go to doesn't want to do the headers, so im probably going to have to spend twice as much now

he said he hates doin headers on hemis