i was wondering if anyone eliminated the hpipe on their car and ran just 2 pipes no xpipe or hpipe just 2 pipes into the mufflers (true duals)
also what did they sound like
any adverse effects
basically pros and cons

 

why would anyone want to do that

 

why would anyone want to do that

well 2 reasons come to mind

1) 2 pieces of straight pipe will flow better than any pipe shaped like an h x pretzel whatever you can bend it into remember quickest diretion to point b from point a is a straight line
x pipe gains 2 hp over h pipe in the fact that is a gradual bend to distribute exhaust h pie is an abrupt 90 degree bend that goes through small minimal hole
so 2 straight pipes will flow better than an x or h or whatever have you

2) x pipes tend to mellow the sound of a c5 by distributing exhaust pulses evenly through each muffler which results in a quieter exhaust note
i have borla stingers and fine the exhaust to be slightly mellower than i would like so if 2 pipes increases the sound just slightly without gaining any resonance thats what im looking for

i hope this answers your question so you can go and put some of that arrogance in another thread dont know if you meant it like it sounds but if you did well there you go
if you cant contribute positively or offer any info dont post at all
thanks

 

I always thought an X or H pipe was to balance out the exhaust gases/backpressure within the exhaust system.

Correct me if I'm wrong.

If you want loud, just run your exhaust off the headers. Who needs cats and muffs anyway?!

 

you could try cutting the connecting H part and patching over where the holes are...should be a cheap enough job and easily reversable.

 

My understanding is that increased hp and tq can be realized with an h or x pipe connection in the exhaust as it creates a beneficial scavenging effect.

 

i can understand how the x would work better than the h
but balancing out the pulse would seem to restrict the exhaust due to the break in flow caused by the x as opposed to straight
unless its a back pressure thing i dont see how it would scavenge anything let along make hp (im no engineer but physics is physics)


jdm
thats what im thinking of doing with the factory h pipe cutting and filling the holes

as far as loud goes i want it slightly louder not deafening emissions illegal loud

 

X pipe and H pipe technology is a product advanced automotive evolution. Anyone who knows anything about modern automotive technology would not want to take a step backwards. "True duels" are are old school , negative, do not scavenge a V8 exhaust pulses evenly for more balanced exhaust performance. One side is always in labor... with an Xpipe or H pipe the back pressure is balanced and exhaust flow pressure from each bank is the same.

 

I'm not the best person to try and explain this scavenging phenomena as I have simply read some info from others. You could try and do a google search or wait for others to comment.

I do know professional race cars (like Nascar) incorporate x pipes in their exhausts so I believe there is value.

 

yes i understand that they do make hp but exactly how is this done
balancing out exhaust pulses as et mentioned is what does it but how exactly does this make hp

 

The H or X pipe helps also to induce some back pressure which is actually benificial and necessary to keep exhaust valves "cooler' or they will fatigue from the higher heat caused by unrestricted flow.

 

for a second i thought I was at ls1tech.com reading the bolt on section

 

so et
how much loss of hp could i look for if i was to just do the 2 pipes
and noone has mentioned the affect it would have on sound
i know the pontiac gto exhaust was designed specifically to have that 60 muscle car sound like the old ones (which utilizd the true dual design)

 

The H or X pipe helps also to induce some back pressure which is actually benificial and necessary to keep exhaust valves "cooler' or they will fatigue from the higher heat caused by unrestricted flow.

yes kinda like straight pipes you will notice a loss of low end torque and gain only on the top end

 

the 60's sound is more a product of 18436572 firing order, than any other one thing, carburetor guzzle, and 11:1 compression . I doubt the New GTO would be designed without a balance pipe...
You keep talking about True duels like its a good thing... true duels is like comparing down draft weber carburetors to fuel injection.
Those 396's and 454 chevelles of the late 60's and 70's with true duels where high 13 second machines from the factory. Today's cars have come a long way since then. Quantum leaps have been made in the last ten years. Today's small block Ls1/LS6 is a high 11 or 12 second machine. Your knowledge of the New exhaust design of the GTO is just a product of Marketing.

 

im not trying to say true duals or good or bad
im just wondering what would the affects be if i were toeliminate the h pipe and run 2 single pipes in a true dual fashion
the gto im not sure if it has the h pie or not
ill look and see

 

et hows this the new gto does not use a h pipe or x pipe the piece that looks like an hpipe is a brace read the info on the exhaust at the bottom of the page
http://www.newagegto.com/News.shtml

 

quoted from the gto page above mentioned


Early in the vehicle development process, engineers test-drove an original 1964 GTO on loan from the Pontiac historical collection to acquaint themselves with its acoustical traits.

"We wanted to get a real good feel for the sound character of the vehicle," Himmelberg explained, "and that drive provided us with an acoustical baseline from which to start."

"We then listened to the 2002 Corvette, which also has a really good sound with traits we were looking for. With those two baselines, we pretty much had in mind what we wanted to accomplish. Our goal was to come in at a pass-by rate of just under 80 decibels, which is the legal sound limit in some states. But, we knew it couldn't be objectionable. It needed to be a pleasing 80 decibels."

At that point, GM engineers in Australia (where the new GTO is built) and North America worked diligently in a parallel effort to develop an exhaust system that delivered the desired sound and performance characteristics.

"It became a true global effort because the exhaust needed to be developed with parts available in Australia, but acoustically tuned to the spirit of an American classic," Himmelberg said.

Through the efforts of engineers on two continents, a true dual exhaust system was developed and acoustically tuned like a finely crafted woodwind instrument, yet enables the heavy-breathing, low-back pressure needs of the 340-horsepower LS1 V8 powerplant. It consists of:

Dual catalytic converters, one on each exhaust bank;
Two resonators - acoustical chambers that are tuned to a specific resonant frequency via internally positioned louvers - are positioned between each catalytic converter and the mufflers;
Two mufflers with different internal flow paths (the right muffler flow path is longer than the left). This achieves a harmonic imbalance between the exhaust paths, enabling engineers to essentially mix tonal qualities to achieve desired sounds;
Specifically sized and routed stainless steel pipes to ensure reduced backpressure as well as desired tonal qualities; and,
A single tubular brace that holds the paths together between the converters and resonators to minimize vibration that could adversely affect the tonal qualities of the system.
Using advanced exhaust modeling capabilities, literally dozens of math-based models were analyzed during system development to refine exhaust flow and detail paths in various components for desired tonal qualities.

"We analyzed and re-analyzed sound qualities at every point of the performance curve," Himmelberg said. "We wanted the rumble at start up, more of a throaty roar during acceleration, and it needed to have a pleasing presence at cruise speeds."

However, the true test came down to what the exhaust note sounded like to the human ear, and the emotions it evoked.

"We had about five prototype builds of the system," Himmelberg recalled, "and for each of them, it really boiled down to listening to them on the GTO. We had 14 different scenarios where we'd listen to and analyze the sound - during acceleration, pass-by on streets, pass-by on highways, idle . . . you name it."

"In the end, we knew we had exactly the sound we wanted. It's hard to hear it and not just grin."

 

OK, I have read the whole article, I have been retired for 3 years but after reading that I can answer your question about how much HP you loss and its 10 HP. IF an LS1 produces 350hp at the crank using a balance pipe, then an LS1 without one will produce 340 at the crank. So Pontiac went for the sound instead of the performance. One of the big negatives about the C5 was it's lack of aggressive sound with the stock system. But with the looks of the New GTO ( not so great ) they needed a Hook to draw in the target market.. The baby Boomers of the 60's, they are now in their THEIR LATE 50'S AND EARLY 60'S. They are not looking for Blinding speed but are looking for sensory gratification. Usually exhaust systems are design to make the most hp, sound comes in as an after thought. IN the Case of the New GTO, too much emphasis was put on exhaust tone at the cost of performance. Atleast that is how I see it..
IT looks like they put alot of resources into bending the sound...

 

Why not basline the car and then do the mod and see what the results are. How can anyone really explain what the new sound would be like? Exhaust sound is so.......personal.

You seem to want to do it. So you should. Then report back to us how it sounds, and how much slower the car runs.