"H" pipe
Technical Article Contributor
Joined: Jun 2002
Posts: 10,511
Likes: 10
From: Under the flightpath of old ORD 22R
Are you looking for True duals, where you cut the factory Y pipe out ?
You made note of wanting to use 2 SI/SO mufflers instead of a SI/DO muffler, so I am leadin towards the fact that you are going true duals from the dumps to the tail pipe.
If you are going this route, use a X pipe istead of a H pipe.
Also make sure to at least the output of the X pipe is 16 ga 304 Stainless Steel pipe. If go Aluminized pipe, you will loose too much heat in the xhst gas, and have a lowered scavenger effects which can cause poor performance with the system.
If you are talking about keeping the factory Y pipe and doing 2 SI/SO mufflers, don't waste your time. It won't be worth the trouble to do this. I would say that would yeild a 0% gain for the trouble over the cat back you have.
Take a look in my gallery for pictures of a Dual system under a SCrew to get an idea of what you are looking at.
Good luck
You made note of wanting to use 2 SI/SO mufflers instead of a SI/DO muffler, so I am leadin towards the fact that you are going true duals from the dumps to the tail pipe.
If you are going this route, use a X pipe istead of a H pipe.
Also make sure to at least the output of the X pipe is 16 ga 304 Stainless Steel pipe. If go Aluminized pipe, you will loose too much heat in the xhst gas, and have a lowered scavenger effects which can cause poor performance with the system.
If you are talking about keeping the factory Y pipe and doing 2 SI/SO mufflers, don't waste your time. It won't be worth the trouble to do this. I would say that would yeild a 0% gain for the trouble over the cat back you have.
Take a look in my gallery for pictures of a Dual system under a SCrew to get an idea of what you are looking at.
Good luck
Technical Article Contributor
Joined: Jun 2002
Posts: 10,511
Likes: 10
From: Under the flightpath of old ORD 22R
Ted,
The H pipe is really use a equalizer of sorts, doesn't really do much else.
The X pipe the shape of it actually accelerates the xhst gas flow through the system ( scavenger effect ) . This is also why the pipe before it has to be SS, to retail the xhst gas heat, to keep the scavenger effect. IF the pipe before the X pipe and the X pipe itself are made of aluminized steel, this would allow too much heat to escape, messing up the xhst gas flow.
The jacking up of flow of the xhst gas is what would cause a TQ loss in a system, not a lack of back pressure as is normally stated.
This is where some will say from a SOTP dyno that a cat back lost them TQ, b/c they lost back pressure on the system, and the truck does not feel like it is working as hard to move anymore.
In reality they might have the same TQ, but less back pressure and a better running engine. This is why a cat back can help with mpg rates, the engine has to work less to get to the same place.
Some systems might jack up the xhst gas flow and create a TQ losss, so don't take this to mean every cat back sustains TQ, or creates a TQ loss over the entire range.
The formula is HP* RPM / 5252 =TQ. Some might sustain TQ at the low side, but loose on the upper side, some might be the reverse of this, some might be dead on with stock, without the back pressure.
So the long and short of it is, if you are taking the time to do true duals by cutting out the factory Y pipe and putting in duals with SI/SO mufflers, do the X pipe and do at least to the output of the X pipe in SS, best results are entire SS system, but this is costly when compared to the aluminized versions of the same.
If you want a better or more detailed explaination on this, call Mike Troyer, listed in the supporting vendor section, he can give you a detailed correct explainition of this, where I might have mis typed something.
Good luck
The H pipe is really use a equalizer of sorts, doesn't really do much else.
The X pipe the shape of it actually accelerates the xhst gas flow through the system ( scavenger effect ) . This is also why the pipe before it has to be SS, to retail the xhst gas heat, to keep the scavenger effect. IF the pipe before the X pipe and the X pipe itself are made of aluminized steel, this would allow too much heat to escape, messing up the xhst gas flow.
The jacking up of flow of the xhst gas is what would cause a TQ loss in a system, not a lack of back pressure as is normally stated.
This is where some will say from a SOTP dyno that a cat back lost them TQ, b/c they lost back pressure on the system, and the truck does not feel like it is working as hard to move anymore.
In reality they might have the same TQ, but less back pressure and a better running engine. This is why a cat back can help with mpg rates, the engine has to work less to get to the same place.
Some systems might jack up the xhst gas flow and create a TQ losss, so don't take this to mean every cat back sustains TQ, or creates a TQ loss over the entire range.
The formula is HP* RPM / 5252 =TQ. Some might sustain TQ at the low side, but loose on the upper side, some might be the reverse of this, some might be dead on with stock, without the back pressure.
So the long and short of it is, if you are taking the time to do true duals by cutting out the factory Y pipe and putting in duals with SI/SO mufflers, do the X pipe and do at least to the output of the X pipe in SS, best results are entire SS system, but this is costly when compared to the aluminized versions of the same.
If you want a better or more detailed explaination on this, call Mike Troyer, listed in the supporting vendor section, he can give you a detailed correct explainition of this, where I might have mis typed something.
Good luck