Stainless LS4 Headers
TECH Apprentice
Joined: Jan 2008
Posts: 323
Likes: 0
First-off, I want to personally apologize to BRYAN(something or other) I didn't mean to jump your ****. But after 1&1/2 years of the same old I'm getting headers made, bullshit, it gets old. I trulie hope you can help in this crusade about headers. As others have failed miserably! But since I have not helped in this action personally I can't complain myself to much, LISTEN FOLKS, I APOLOGIZE TO THIS PERSON FOR MY ACTIONS ABOUT LS4 HEADERS, IF YOU CAN HELP OUT THE LS4 COMUNITY PLEASE DO. SORRY AGAIN FOR THE FAULTS I MADE AGAINST YOU BRYAN!
TECH Fanatic
Joined: Jul 2007
Posts: 1,115
Likes: 0
From: Reading, Pennsylvania
What's wrong with these people? Find out how many people they will need to put money up front to get them made and you'll have headers. Simple as that. Everyone backs out once the ball gets rolling and people need to actually put money out. That is why you don't get headers. I could personally care less about headers that's why I haven't done anything to help.
Registered User
Joined: Dec 2008
Posts: 5
Likes: 0
Guys,
Here's a couple of possibilities;
1) Leave the stock exhaust manifolds in place, but give the car *TRUE* dual exhaust (Yes folks, our cars are actually single exhaust beasts, and just that one change of going from single to dual might net you 20 HP *easy*. Recall that Chevy gets 6-8 HP from a cheesy dual-mode muffler on the 'Vette.). Unless you're planning to run serious times with your car, you might come to find that the current exhaust manifolds are not too bad. They are very similar to the style which AMC used between 1971-1974, with much success, and are far better than some monstrosities currently in production.
GM uses a system similar to what Chrysler uses to help damp out some of the low-frequency droning which rears its ugly head at low RPM and 4-cylinder mode: that huge resonator under our cars. In contrast to the Chrysler's twin-exhaust DOD resonator, it is from this point back that the LS4 runs a fundamentally single exhaust. If we kept our current manifolds, but split the left and right sides of the exhaust into separate runs, rather than using the current single run which cosmetically splits into two at the end, we would not only see a world of improvement, but the car would also start to sound like a V-8, which would really be nice.
2) This next tactic for more power might be a bit sketchy, as it requires untried items. One of the lesser known facts about our engines, is that we run the same heads as the LS6, and as a result (unless all LS heads have exactly the same port dimensions anyway, making this part of my post redundant), it would reason that LS6 cylinder head accessories would fit our engines too. Looking at our cars and their engine installations, it would seem to me that a pair of C-5 Z06 Shorty Headers would just barely squeeze in (they run about $550, depending on source). They are just slightly larger that the stock manifolds, and would certainly provide a less turbulent flow than stock units do. The approach would require a muffler shop to fabricate pipes from both the "front" and "back" exhaust manifolds, to cats, and ultimately, mufflers. While more expensive, this would be a complete solution, giving the car true dual exhaust, a decent manifold, and free-flow mufflers. The large center resonator/cat combo would be ditched, and in its space, the pair of pipes would be installed, coursing back to the mufflers. One would have to install two catalytic converters, but realistically, practically any pair would work, or, they might be removed completely - but only for off-road use, of course.
Fabrication rates vary according to locality, but plan for the majority of the work to be allocated to bending the "front" manifold pipe around the motor, and running it back to the stock muffler pipes (these can be re-used, so there's no need to replace them). The collector/pipe on the "back" cylinder bank will be much easier, as it needs only be fabricated, and run back. Again, given Chevy's experience with dual-mode exhaust on the Corvette, you might be able to net another 7-8 more H.P. by replacing the fiberglass-stuffed stock pieces, with free-flowing, parabolic-resonator designs from companies such as Dynomax, Flowmaster, GHL, or whatever you prefer. The end result would be a racier exhaust note, as well as more power - for the extra cost of the mufflers ($125 each), and their installation ($depends on locality$). Parts aside, I can't see a legit muffler shop charging more than about 4 hours at their established rate to do the job. However, on the other end of that spectrum, I know a local shop that would probably tackle a job like that with a two-hour time estimate......
Even if you figure in for large discrepancies in the price of labor across the nation, I can't see how the entire job would come out to much more than $1,600, including Z06 shorty headers, piping, generic cats, and a pair of DynoMax or Flowmaster mufflers (about $125 each), all including labor. If you have *REALLY* expensive shops in your areas, I can see the price going to maybe $2,000, but no more. If the number gets too much higher than that, somebody is smelling blood in the water....
I consider my 2008 GXP to be a gorgeous car, as it is loaded to the hilt with extras, including Nav, sunroof, suede, etc., and is a beautiful shade of midnight blue, with a black and tan interior. I bought the car as a replacement to my mythical 2007 Z06, and I plan to have it as my daily driver when I re-acquire another Z06 - possibly an '09. My plans are to attempt a mild upgrade to the car, either item #1), or #2), above, along with a free-flowing air-filter, a throttle body, thermostat/temperature reduction, a programmer, and a set of Crane 1.8:1 rocker arms. I checked my horsepower kinematically, and I got 297 max - not bad for a machine rated at 303 tops! I prefer kinematic measurements as they let you see what is happening on the road, both for the better, such as the effects of ram air, etc, and the worse, such as the effects of heat soak, and chassis limitations.
Peace.
Moe
Here's a couple of possibilities;
1) Leave the stock exhaust manifolds in place, but give the car *TRUE* dual exhaust (Yes folks, our cars are actually single exhaust beasts, and just that one change of going from single to dual might net you 20 HP *easy*. Recall that Chevy gets 6-8 HP from a cheesy dual-mode muffler on the 'Vette.). Unless you're planning to run serious times with your car, you might come to find that the current exhaust manifolds are not too bad. They are very similar to the style which AMC used between 1971-1974, with much success, and are far better than some monstrosities currently in production.
GM uses a system similar to what Chrysler uses to help damp out some of the low-frequency droning which rears its ugly head at low RPM and 4-cylinder mode: that huge resonator under our cars. In contrast to the Chrysler's twin-exhaust DOD resonator, it is from this point back that the LS4 runs a fundamentally single exhaust. If we kept our current manifolds, but split the left and right sides of the exhaust into separate runs, rather than using the current single run which cosmetically splits into two at the end, we would not only see a world of improvement, but the car would also start to sound like a V-8, which would really be nice.
2) This next tactic for more power might be a bit sketchy, as it requires untried items. One of the lesser known facts about our engines, is that we run the same heads as the LS6, and as a result (unless all LS heads have exactly the same port dimensions anyway, making this part of my post redundant), it would reason that LS6 cylinder head accessories would fit our engines too. Looking at our cars and their engine installations, it would seem to me that a pair of C-5 Z06 Shorty Headers would just barely squeeze in (they run about $550, depending on source). They are just slightly larger that the stock manifolds, and would certainly provide a less turbulent flow than stock units do. The approach would require a muffler shop to fabricate pipes from both the "front" and "back" exhaust manifolds, to cats, and ultimately, mufflers. While more expensive, this would be a complete solution, giving the car true dual exhaust, a decent manifold, and free-flow mufflers. The large center resonator/cat combo would be ditched, and in its space, the pair of pipes would be installed, coursing back to the mufflers. One would have to install two catalytic converters, but realistically, practically any pair would work, or, they might be removed completely - but only for off-road use, of course.
Fabrication rates vary according to locality, but plan for the majority of the work to be allocated to bending the "front" manifold pipe around the motor, and running it back to the stock muffler pipes (these can be re-used, so there's no need to replace them). The collector/pipe on the "back" cylinder bank will be much easier, as it needs only be fabricated, and run back. Again, given Chevy's experience with dual-mode exhaust on the Corvette, you might be able to net another 7-8 more H.P. by replacing the fiberglass-stuffed stock pieces, with free-flowing, parabolic-resonator designs from companies such as Dynomax, Flowmaster, GHL, or whatever you prefer. The end result would be a racier exhaust note, as well as more power - for the extra cost of the mufflers ($125 each), and their installation ($depends on locality$). Parts aside, I can't see a legit muffler shop charging more than about 4 hours at their established rate to do the job. However, on the other end of that spectrum, I know a local shop that would probably tackle a job like that with a two-hour time estimate......Even if you figure in for large discrepancies in the price of labor across the nation, I can't see how the entire job would come out to much more than $1,600, including Z06 shorty headers, piping, generic cats, and a pair of DynoMax or Flowmaster mufflers (about $125 each), all including labor. If you have *REALLY* expensive shops in your areas, I can see the price going to maybe $2,000, but no more. If the number gets too much higher than that, somebody is smelling blood in the water....
I consider my 2008 GXP to be a gorgeous car, as it is loaded to the hilt with extras, including Nav, sunroof, suede, etc., and is a beautiful shade of midnight blue, with a black and tan interior. I bought the car as a replacement to my mythical 2007 Z06, and I plan to have it as my daily driver when I re-acquire another Z06 - possibly an '09. My plans are to attempt a mild upgrade to the car, either item #1), or #2), above, along with a free-flowing air-filter, a throttle body, thermostat/temperature reduction, a programmer, and a set of Crane 1.8:1 rocker arms. I checked my horsepower kinematically, and I got 297 max - not bad for a machine rated at 303 tops! I prefer kinematic measurements as they let you see what is happening on the road, both for the better, such as the effects of ram air, etc, and the worse, such as the effects of heat soak, and chassis limitations.
Peace.
Moe
Last edited by Richiec77; Jan 5, 2009 at 11:04 PM. Reason: MOAR suckage!!
Guys,
Here's a couple of possibilities;
1) Leave the stock exhaust manifolds in place, but give the car *TRUE* dual exhaust (Yes folks, our cars are actually single exhaust beasts, and just that one change of going from single to dual might net you 20 HP *easy*. Recall that Chevy gets 6-8 HP from a cheesy dual-mode muffler on the 'Vette.). Unless you're planning to run serious times with your car, you might come to find that the current exhaust manifolds are not too bad. They are very similar to the style which AMC used between 1971-1974, with much success, and are far better than some monstrosities currently in production.
GM uses a system similar to what Chrysler uses to help damp out some of the low-frequency droning which rears its ugly head at low RPM and 4-cylinder mode: that huge resonator under our cars. In contrast to the Chrysler's twin-exhaust DOD resonator, it is from this point back that the LS4 runs a fundamentally single exhaust. If we kept our current manifolds, but split the left and right sides of the exhaust into separate runs, rather than using the current single run which cosmetically splits into two at the end, we would not only see a world of improvement, but the car would also start to sound like a V-8, which would really be nice.
2) This next tactic for moar power might be a bit sketchy, as it requires untried items. One of the lesser known facts about our engines, is that we run the same heads as the LS6, and as a result (unless all LS heads have exactly the same port dimensions anyway, making this part of my post redundant), it would reason that LS6 cylinder head accessories would fit our engines too. Looking at our cars and their engine installations, it would seem to me that a pair of C-5 Z06 Shorty Headers would just barely squeeze in (they run about $550, depending on source). They are just slightly larger that the stock manifolds, and would certainly provide a less turbulent flow than stock units do. The approach would require a muffler shop to fabricate pipes from both the "front" and "back" exhaust manifolds, to cats, and ultimately, mufflers. While more expensive, this would be a complete solution, giving the car true dual exhaust, a decent manifold, and free-flow mufflers. The large center resonator/cat combo would be ditched, and in its space, the pair of pipes would be installed, coursing back to the mufflers. One would have to install two catalytic converters, but realistically, practically any pair would work, or, they might be removed completely - but only for off-road use, of course. Fabrication rates vary according to locality, but plan for the majority of the work to be allocated to bending the "front" manifold pipe around the motor, and running it back to the stock muffler pipes (these can be re-used, so there's no need to replace them). The collector/pipe on the "back" cylinder bank will be much easier, as it needs only be fabricated, and run back. Again, given Chevy's experience with dual-mode exhaust on the Corvette, you might be able to net another 7-8 moar H.P. by replacing the fiberglass-stuffed stock pieces, with free-flowing, parabolic-resonator designs from companies such as Dynomax, Flowmaster, GHL, or whatever you prefer. The end result would be a racier exhaust note, as well as moar power - for the extra cost of the mufflers ($125 each), and their installation ($depends on locality$). Parts aside, I can't see a legit muffler shop charging moar than about 4 hours at their established rate to do the job. However, on the other end of that spectrum, I know a local shop that would probably tackle a job like that with a two-hour time estimate......
Even if you figure in for large discrepancies in the price of labor across the nation, I can't see how the entire job would come out to much moar than $1,600, including Z06 shorty headers, piping, generic cats, and a pair of DynoMax or Flowmaster mufflers (about $125 each), all including labor. If you have *REALLY* expensive shops in your areas, I can see the price going to maybe $2,000, but no moar. If the number gets too much higher than that, somebody is smelling blood in the water....
I consider my 2008 GXP to be a gorgeous car, as it is loaded to the hilt with extras, including Nav, sunroof, suede, etc., and is a beautiful shade of midnight blue, with a black and tan interior. I bought the car as a replacement to my mythical 2007 Z06, and I plan to have it as my daily driver when I re-acquire another Z06 - possibly an '09. My plans are to attempt a mild upgrade to the car, either item #1), or #2), above, along with a free-flowing air-filter, a throttle body, thermostat/temperature reduction, a programmer, and a set of Crane 1.8:1 rocker arms. I checked my horsepower kinematically, and I got 297 max - not bad for a machine rated at 303 tops! I prefer kinematic measurements as they let you see what is happening on the road, both for the better, such as the effects of ram air, etc, and the worse, such as the effects of heat soak, and chassis limitations.
Peace.
Moe
Here's a couple of possibilities;
1) Leave the stock exhaust manifolds in place, but give the car *TRUE* dual exhaust (Yes folks, our cars are actually single exhaust beasts, and just that one change of going from single to dual might net you 20 HP *easy*. Recall that Chevy gets 6-8 HP from a cheesy dual-mode muffler on the 'Vette.). Unless you're planning to run serious times with your car, you might come to find that the current exhaust manifolds are not too bad. They are very similar to the style which AMC used between 1971-1974, with much success, and are far better than some monstrosities currently in production.
GM uses a system similar to what Chrysler uses to help damp out some of the low-frequency droning which rears its ugly head at low RPM and 4-cylinder mode: that huge resonator under our cars. In contrast to the Chrysler's twin-exhaust DOD resonator, it is from this point back that the LS4 runs a fundamentally single exhaust. If we kept our current manifolds, but split the left and right sides of the exhaust into separate runs, rather than using the current single run which cosmetically splits into two at the end, we would not only see a world of improvement, but the car would also start to sound like a V-8, which would really be nice.
2) This next tactic for moar power might be a bit sketchy, as it requires untried items. One of the lesser known facts about our engines, is that we run the same heads as the LS6, and as a result (unless all LS heads have exactly the same port dimensions anyway, making this part of my post redundant), it would reason that LS6 cylinder head accessories would fit our engines too. Looking at our cars and their engine installations, it would seem to me that a pair of C-5 Z06 Shorty Headers would just barely squeeze in (they run about $550, depending on source). They are just slightly larger that the stock manifolds, and would certainly provide a less turbulent flow than stock units do. The approach would require a muffler shop to fabricate pipes from both the "front" and "back" exhaust manifolds, to cats, and ultimately, mufflers. While more expensive, this would be a complete solution, giving the car true dual exhaust, a decent manifold, and free-flow mufflers. The large center resonator/cat combo would be ditched, and in its space, the pair of pipes would be installed, coursing back to the mufflers. One would have to install two catalytic converters, but realistically, practically any pair would work, or, they might be removed completely - but only for off-road use, of course.
Fabrication rates vary according to locality, but plan for the majority of the work to be allocated to bending the "front" manifold pipe around the motor, and running it back to the stock muffler pipes (these can be re-used, so there's no need to replace them). The collector/pipe on the "back" cylinder bank will be much easier, as it needs only be fabricated, and run back. Again, given Chevy's experience with dual-mode exhaust on the Corvette, you might be able to net another 7-8 moar H.P. by replacing the fiberglass-stuffed stock pieces, with free-flowing, parabolic-resonator designs from companies such as Dynomax, Flowmaster, GHL, or whatever you prefer. The end result would be a racier exhaust note, as well as moar power - for the extra cost of the mufflers ($125 each), and their installation ($depends on locality$). Parts aside, I can't see a legit muffler shop charging moar than about 4 hours at their established rate to do the job. However, on the other end of that spectrum, I know a local shop that would probably tackle a job like that with a two-hour time estimate......Even if you figure in for large discrepancies in the price of labor across the nation, I can't see how the entire job would come out to much moar than $1,600, including Z06 shorty headers, piping, generic cats, and a pair of DynoMax or Flowmaster mufflers (about $125 each), all including labor. If you have *REALLY* expensive shops in your areas, I can see the price going to maybe $2,000, but no moar. If the number gets too much higher than that, somebody is smelling blood in the water....
I consider my 2008 GXP to be a gorgeous car, as it is loaded to the hilt with extras, including Nav, sunroof, suede, etc., and is a beautiful shade of midnight blue, with a black and tan interior. I bought the car as a replacement to my mythical 2007 Z06, and I plan to have it as my daily driver when I re-acquire another Z06 - possibly an '09. My plans are to attempt a mild upgrade to the car, either item #1), or #2), above, along with a free-flowing air-filter, a throttle body, thermostat/temperature reduction, a programmer, and a set of Crane 1.8:1 rocker arms. I checked my horsepower kinematically, and I got 297 max - not bad for a machine rated at 303 tops! I prefer kinematic measurements as they let you see what is happening on the road, both for the better, such as the effects of ram air, etc, and the worse, such as the effects of heat soak, and chassis limitations.
Peace.
Moe
First, you can throw out values and prices and parts that *may* fit until you realize that its not price or parts that are stopping all us LS4 guys, its space. Have you opened the hood of your GXP? Space is really at a premium, and shoehorning a V8 into the car left GM engineers no choice but to rig up the restrictive V6 exhaust to the car and choke out our beast.
Now TD's sound great rolling off the tongue and on a LSx car, but to get a correct TD system, you would have to reduce each bank's exhaust pipe to about 2 inches. Now that is restrictive. That is detrimental to power. And the topic of using shorty headers has been beat to death here over and over again along with the prospect of someone making us manifolds. THe problem with short headers is that most of the collectors exit at the bottom when the exit needed for our LS4 cars happens to exit to the right and back towards the driver. The crossover pipe itself is a fubar'ed design along with the back manifold. The back manifold then brings up a problem because then the exit does not connect to the pipe the exits the engine bay.
Since neither of those exploits have proven sucessful...I think we better just give up until someone cares about us enough to put some serious R&D other than some backyard engineering...cause this is an uphill battle.
TECH Regular
Joined: Oct 2004
Posts: 457
Likes: 0
From: Bay Area, CA
That's one of the things I've thought of in my head as well, but is it worse than both banks emptying down a 2.5" pipe splitting off to dual 1.75" at the rear?
Registered User
Joined: Dec 2008
Posts: 5
Likes: 0
This is the 2nd time I'm typing this, as my post got dumped when I removed my popup blocker....
Regarding backpressure, I agree that it can be a touchy subject; Chrysler's 3.5 liter V-6 actually makes more power on the stock single exhaust than it does on a SS dual system. V-8s, on the other hand, seem to like to breathe freely.
The subject is truly complex, and while it is certainly true that reducing pipe diameter when going from single to dual will help keep flow velocity high, valve timing, and exhaust port flow characteristics are by far the more impactful fluid dynamics variables, when considering the impact of sizing on back pressure.
I am considering experimenting with *some* kind of mod, just because we are so data starved with our engines, and any info could prove useful.
BTW, to Red03GT, if you just want a quick rule of thumb of the diameter to go to when switching from single to dual, simply multiply the original pipe diameter by .707 (the square-root of two, over two). This will get you in the ball park, but the two smaller pipes will always flow more than one large one of equal area, due to Bernoulli's principle. Given a single 2.5" pipe replaced by a pipe off each cylinder bank, that gives us; 2.5 * .707 = 1.76", so your 1.75" pipe would work fine. A 2" pipe would flow even better, but once again, factors like exhaust gas temperature, pipe length, system resonance, and even the effects of valve overlap would all contribute their share to the final verdict. My call? the 2" would probably run even better than the 1.75", but I admit that's due more to gut feeling, than any hallowed principal of causality. Again, remember the Corvette and its 8 HP gain from the cheesy muffler.....
Peace.
Moe
Regarding backpressure, I agree that it can be a touchy subject; Chrysler's 3.5 liter V-6 actually makes more power on the stock single exhaust than it does on a SS dual system. V-8s, on the other hand, seem to like to breathe freely.
The subject is truly complex, and while it is certainly true that reducing pipe diameter when going from single to dual will help keep flow velocity high, valve timing, and exhaust port flow characteristics are by far the more impactful fluid dynamics variables, when considering the impact of sizing on back pressure.
I am considering experimenting with *some* kind of mod, just because we are so data starved with our engines, and any info could prove useful.
BTW, to Red03GT, if you just want a quick rule of thumb of the diameter to go to when switching from single to dual, simply multiply the original pipe diameter by .707 (the square-root of two, over two). This will get you in the ball park, but the two smaller pipes will always flow more than one large one of equal area, due to Bernoulli's principle. Given a single 2.5" pipe replaced by a pipe off each cylinder bank, that gives us; 2.5 * .707 = 1.76", so your 1.75" pipe would work fine. A 2" pipe would flow even better, but once again, factors like exhaust gas temperature, pipe length, system resonance, and even the effects of valve overlap would all contribute their share to the final verdict. My call? the 2" would probably run even better than the 1.75", but I admit that's due more to gut feeling, than any hallowed principal of causality. Again, remember the Corvette and its 8 HP gain from the cheesy muffler.....
Peace.
Moe
Last edited by Richiec77; Jan 5, 2009 at 11:06 PM. Reason: MOAR suckage!!
This is the 2nd time I'm typing this, as my post got dumped when I removed my popup blocker....
Regarding backpressure, I agree that it can be a touchy subject; Chrysler's 3.5 liter V-6 actually makes moar power on the stock single exhaust than it does on a SS dual system. V-8s, on the other hand, seem to like to breathe freely.
The subject is truly complex, and while it is certainly true that reducing pipe diameter when going from single to dual will help keep flow velocity high, valve timing, and exhaust port flow characteristics are by far the more impactful fluid dynamics variables, when considering the impact of sizing on back pressure.
I am considering experimenting with *some* kind of mod, just because we are so data starved with our engines, and any info could prove useful.
BTW, to Red03GT, if you just want a quick rule of thumb of the diameter to go to when switching from single to dual, simply multiply the original pipe diameter by .707 (the square-root of two, over two). This will get you in the ball park, but the two smaller pipes will always flow moar than one large one of equal area, due to Bernoulli's principle. Given a single 2.5" pipe replaced by a pipe off each cylinder bank, that gives us; 2.5 * .707 = 1.76", so your 1.75" pipe would work fine. A 2" pipe would flow even better, but once again, factors like exhaust gas temperature, pipe length, system resonance, and even the effects of valve overlap would all contribute their share to the final verdict. My call? the 2" would probably run even better than the 1.75", but I admit that's due moar to gut feeling, than any hallowed principal of causality. Again, remember the Corvette and its 8 HP gain from the cheesy muffler.....
Peace.
Moe
Regarding backpressure, I agree that it can be a touchy subject; Chrysler's 3.5 liter V-6 actually makes moar power on the stock single exhaust than it does on a SS dual system. V-8s, on the other hand, seem to like to breathe freely.
The subject is truly complex, and while it is certainly true that reducing pipe diameter when going from single to dual will help keep flow velocity high, valve timing, and exhaust port flow characteristics are by far the more impactful fluid dynamics variables, when considering the impact of sizing on back pressure.
I am considering experimenting with *some* kind of mod, just because we are so data starved with our engines, and any info could prove useful.
BTW, to Red03GT, if you just want a quick rule of thumb of the diameter to go to when switching from single to dual, simply multiply the original pipe diameter by .707 (the square-root of two, over two). This will get you in the ball park, but the two smaller pipes will always flow moar than one large one of equal area, due to Bernoulli's principle. Given a single 2.5" pipe replaced by a pipe off each cylinder bank, that gives us; 2.5 * .707 = 1.76", so your 1.75" pipe would work fine. A 2" pipe would flow even better, but once again, factors like exhaust gas temperature, pipe length, system resonance, and even the effects of valve overlap would all contribute their share to the final verdict. My call? the 2" would probably run even better than the 1.75", but I admit that's due moar to gut feeling, than any hallowed principal of causality. Again, remember the Corvette and its 8 HP gain from the cheesy muffler.....
Peace.
Moe
Secondly, are you kidding? 1.75in pipe for a v8 just so you can say you have TDs???
Bernoulli's principle only works with fluid pressure, he worked on hydrodyanmics, not gasses.
Why multiply by rad 2 over 2.....dude you make no sense.
I'd advise leaving that GXP stock for awhile and do some reading in these forums and about engine theory before you start crunching numbers and throwing out principles and theories on why TDs would work.
Registered User
Joined: Dec 2008
Posts: 5
Likes: 0
First of all, moar=more.
Secondly, are you kidding? 1.75in pipe for a v8 just so you can say you have TDs???
Bernoulli principle only works with fluid pressure, he worked on hydrodynamics, not gasses.
Why multiply by rad 2 over 2.....dude you make no sense.
I'd advise leaving that GXP stock for awhile and do some reading in these forums and about engine theory before you start crunching numbers and throwing out principles and theories on why TDs would work.
Secondly, are you kidding? 1.75in pipe for a v8 just so you can say you have TDs???
Bernoulli principle only works with fluid pressure, he worked on hydrodynamics, not gasses.
Why multiply by rad 2 over 2.....dude you make no sense.
I'd advise leaving that GXP stock for awhile and do some reading in these forums and about engine theory before you start crunching numbers and throwing out principles and theories on why TDs would work.
Ummm.....
I hate to directly contradict anyone, but....
Gasses are fluids. The technical definition of a fluid is any substance that takes the shape of its physically limiting ambient. Therefore, all gasses are fluids, but not all fluids are gasses.
Secondly, Bernoulli worked with all fluids, but mainly gasses; Bernoulli's theorem regards the normal pressure of gasses on their boundaries, with respect to their velocities relative to that boundary (in this case, "normal" means; "perpendicular to"). This theory explains, most famously, why aircraft fly, but it also contributes to exhaust flow dynamics in open pipes.
With regard to .707; if you want to keep the area of a round pipe constant, but split it into two pipes, you multiply the diameter of the original pipe by the square root of two, over two (.707). The cross-sectional area of a pipe (and therefore its flow capacity) is equal to Pi times the radius squared (3.14159*R^2), so if you want to double a pipe's cross-sectional area, you multiply its radius by the square root of two; if you want to triple the area, you multiply by the square root of three. Conversely, if you want to find the radius of a pipe with half of the original's flow capacity, you multiply the original's radius by the square root of two, over two. Try it.
Last but not least, if we consider a single exhaust with a particular cross-sectional area, say with 2.5" pipes, we could theoretically increase its flow capability by simply splitting the system into two separate pipes of equal combined area. Crudely explained, it is this phenomenon (again, quantified by Bernoulli) which is exploited by engine manufacturers who implement multi-valve heads to squeeze every bit of power out of an engine. Two 1.41" valves will actually flow better than a single 2.0" valve, even if their combined areas are no greater than the single, larger valve.
What's the "right" thing to do? Who knows, but like I said, I'm up for a little experimentation, partially because I enjoy the sport, and partially because we could all use more data on these cars than we have.
Peace.
Moe
p.s.; More = Moar = internets thing
Last edited by Richiec77; Jan 5, 2009 at 11:08 PM. Reason: MOAR suckage!!
and about the true dual it might flow slightly better and gain some power but the weight of the exhaust tubing and mufflers that will be added. instead of messing with that im just going to run tubing to a borla muffler and have it kick out before the passenger rear tire freer flowing and lighter and since our cars have transmission issues with power. i think losing weight is a safer approach, i also think if somone used that oval tubing some circle track racers use that would be interesting
sorry i was not being clear i meant muffler and tubing weight from the two bolt flange and back if i wanted to do any exhaust upstream of that i would have to buy and learn hp tuner.... which i want to do but during school months it is just not a reality my car is pretty much put away for the winter
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I took another look at our exhausts, and I think it breaks down like this;
1) A shorty header would resolve the abrupt transition from exhaust port to manifold that we currently have, obviously worse on one side than the other.
2) Pauls325 is correct that a pair of pipes would be slightly heavier than a single larger pipe, as surface area (and therefore weight) of a pipe increases linearly with radius, while the CS area increases as the square.
3) We would stand to partially offset the above weight penalty by removing the massive resonator/cat assembly currently in use in our cars - in fact, removal of this monster might offset it completely. Stay tuned as weights for both are posted.
4) My main concern is the union of the front/back exhaust flux so far upstream in the exhaust system. At the point where they meet, the gasses still have tremendous energy, mainly in the form of thermal potential, but almost equally as much in kinetic energy. Here is where a well-designed header collector/reducer is worth its weight in gold; the trick at this point is to ideally match the taper of the reducer to the exhaust stream's reduction in thermal potential. As the gasses cool, they become denser, and therefore require less pipe area to flow at a particular velocity. Since Bernoulli proved that fluid pressure is proportional to its velocity, the reduction in pipe diameter at this point would ideally keep that exhaust gasses at a constant velocity as they cooled off, to keep backpressure from increasing. I say "ideally" because a plethora of variables affect that trade off, and designers have to come up with a design which will work reasonably well across a broad range of conditions.
Lastly, it's obvious to me that our exhaust systems' design was influenced far moar by a bunch of bean counters trying to keep costs down, than engineers trying to get the most HP out of the LS4. Obviously, every engineer works under the mantra of keeping costs down, but the ridiculous two into one, into two layout we've been given, just reeks of a system that was designed to work at the absolute lowest cost. Working out a smoother transition upstream, where the two cylinder banks join, AND implementing a free-flow muffler design, should net a palpable increase in power over what we currently produce.