face it, many, maybe, most muffler shops want you in and out of thier bays as fast as possiable and want to use the least expensive components they can find , and want to take the least effort and time they can, yet derive the most proffit, from the work. you can totally avoid that by either buying top quality components and paying big bucks, or...if your budgets like mine....
if something BREAKS , well,thats a P.I.T.A., and probably a badly designed or improperly installed component, but thats what WELDERS are designed for.....learn to weld and things like that are at most a minor repair that will usually take well under 30 minutes and its almost certain that you can put some thought into the repair and make it darn near "bullet proof"
and very unlikely to re-occure
no part is immune from a bad installation.
in fact! once you learn to weld and you can weld up a totally custom exhaust that will exactly match your design and application goals for far less than you can buy one for, in cheap aluminized steel or the far better stainless steel
put some thought into the system design, having the correct diam exhaust pipes and an (X) pipe connecting the two sides as close to the engines as space under the car allows helps performance,having the muffler as far rear as possible has both performance and sound benefits. Exhaust gasses will naturally slow down cool and expand and the individual exhaust pulse strength dissipates, the further it travels through a pipe, also the extra length will help dissipate sound waves , and smooth the flow making the muffler theoretically less intrusive to exhaust flow and quieter. minimizing back pressure past the header collectors and (X) pipe should be a major factor in your exhaust system design calculations as that will tend to increase exhaust scavenging efficiency if the headers are correctly designed.
FAILURE TO READ THE LINKS AND SUB LINKS SIGNIFICANTLY REDUCES THE USEFUL INFO YOU HAVE ACCESS TOO!
http://store.summitracing.com/egnse...+kit&searchinresults=false&N=700+115&y=6&x=32
http://www.jegs.com/webapp/wcs/stores/servlet/category_10001_10002_11525_-1_10245
http://www.magnaflow.com/02product/universalsatinxl.asp
http://www.flowmastermufflers.com/mufflers.html
viewtopic.php?f=32&t=1174&p=2404#p2404
http://www.superchevy.com/technical/eng ... index.html
http://www.borla.com/products/universal.aspx
http://home.flash.net/~ivc1/cobra/xpipes.html
you can build your own stainless steel exhaust system and personally install it and its very unlikely to cost nearly what youll pay a muffler shop, BUT USE A MINIMUM 16GA 18 GA is too THIN, FOR STAINLESS HEADERS OR EXHAUST PIPE, AND DON,T FORGET TO PURGE THE BACK GAS WHEN WELDING ,and if you shop for components carefully youll find that a stainless exhaust will cost only slightly more than the muffler shop charges for inferior aluminized steel
if your going thru the work do it correctly, buy and install decent components so your not back doing it again in a year or so!
careful measurement and planing, and component sellection, will help a great deal in keeping costs low!
BUT THEN I ONLY BUY AND INSTALL STAINLESS COMPONENTS IF GIVEN AN OPTION, INSTALL THEM MYSELF, AND CAN,T REMEMBER HAVING PROBLEMS INSTALLING OR HAVING A COMPONENT FAIL IF ITS PROPERLY INSTALLED...QUALITY EXHAUST HANGERS DON,T GENERALLY FAIL AND QUALITY WELDS DON,T GENERALLY BREAK, AND IF YOU INSTALL IN CORRECTLY YOURSELF AND CAN WELD YOULL SAVE MONEY AND HAVE THE EQUIPMENT AND SKILL TO FIX IT IN THE UNLIKELY EVENT IT DID BREAK
JUST ONE MORE REASON TO LEARN TO WELD AND HAVE ACCESS TO A GOOD MIG,TIG, OR OXY-ACETOLENE TORCH
theres plenty of fluid dynamics math and research out there to show that the distances the exhaust travels between exhaust pulses and the diam. and length are easily calculated, and past that length the second previous pulse has little effect compared to the current and previous pulse energy and reflective wave
and lets not forget the cam timing displacement and intake port all effect the cylinder scavaging the headers can effectively provide also
http://www.engr.colostate.edu/~allan/fluids/page7/PipeLength/pipe.html
http://www.rbracing-rsr.com/runnertorquecalc.html
http://victorylibrary.com/mopar/header-tech-c.htm
http://www.headerdesign.com/
http://www.pontiacracing.net/js_header_length1.htm
http://www.slowgt.com/Calc2.htm#Header
example , my 383 vette has a cam with exhaust cam timing that opens at 83degs bbdc, thats 97 degs atdc, http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=119661&lvl=2&prt=5
Bore: (Inches) 4.03"<BR>Exhaust Valve Opening Point: (Degrees ATDC) 97 degs
Peak Power RPM: 5500rpm Calculated information appears below
Header Pipe Diameter: (Inches) 1.84"<
Header Pipe Length: (Inches) 37.65
Collector Diameter: (Inches) 3.5
Collector Length: (Inches) 18.82
so ideally the (X) is placed at that point to maximize scavaging but thats not always possiable due to clearance, and if you choose to place an (H) just before the mufflers its mostly to reduce resonance or noise not increase scavaging but it tends to reduce the restriction to flow
most guys I talk and deal with,seem to think that slapping a set of headers on thier car is all thats required to boost performance....ANY HEADERS! ...and they fail to realize that both the header design and the exhaust system behind them require a good deal of thought if you want the maximum benefits, and that simply hooking a restrictive exhaust system to the collectors on the best headers will negate most of thier potential benefits.
most commercial headers are designed mostly for ease of manufacturing and ease of installation,little thought goes into maximizing the cylinder scavaging which is thier main function.
your fooling yourself if you think headers will provide a big boost in hp/tq without the low restriction exhaust behind them,and in most cases that requires a larger dia. exhaust system and adding an (X) to the system and extending the header collectors at thier full dia. up till at least the exit of the (X) so the twin exhaust pipes cross sectional area can provide that reduced restriction to flow, rather than the reducers many guys install to the collector exits to adapt them to the stock exhaust system
http://garage.grumpysperformance.com/index.php?threads/a-well-designed-c4-exhaust.786/
example of a well laid out exhaust (MELROSE)
but even that system could be hurt if you slap restrictive mufflers on it
if something BREAKS , well,thats a P.I.T.A., and probably a badly designed or improperly installed component, but thats what WELDERS are designed for.....learn to weld and things like that are at most a minor repair that will usually take well under 30 minutes and its almost certain that you can put some thought into the repair and make it darn near "bullet proof"
and very unlikely to re-occure
no part is immune from a bad installation.
in fact! once you learn to weld and you can weld up a totally custom exhaust that will exactly match your design and application goals for far less than you can buy one for, in cheap aluminized steel or the far better stainless steel
put some thought into the system design, having the correct diam exhaust pipes and an (X) pipe connecting the two sides as close to the engines as space under the car allows helps performance,having the muffler as far rear as possible has both performance and sound benefits. Exhaust gasses will naturally slow down cool and expand and the individual exhaust pulse strength dissipates, the further it travels through a pipe, also the extra length will help dissipate sound waves , and smooth the flow making the muffler theoretically less intrusive to exhaust flow and quieter. minimizing back pressure past the header collectors and (X) pipe should be a major factor in your exhaust system design calculations as that will tend to increase exhaust scavenging efficiency if the headers are correctly designed.
FAILURE TO READ THE LINKS AND SUB LINKS SIGNIFICANTLY REDUCES THE USEFUL INFO YOU HAVE ACCESS TOO!
http://www.jegs.com/webapp/wcs/stores/servlet/category_10001_10002_11525_-1_10245
http://www.magnaflow.com/02product/universalsatinxl.asp
http://www.flowmastermufflers.com/mufflers.html
viewtopic.php?f=32&t=1174&p=2404#p2404
http://www.superchevy.com/technical/eng ... index.html
http://www.borla.com/products/universal.aspx
http://home.flash.net/~ivc1/cobra/xpipes.html
you can build your own stainless steel exhaust system and personally install it and its very unlikely to cost nearly what youll pay a muffler shop, BUT USE A MINIMUM 16GA 18 GA is too THIN, FOR STAINLESS HEADERS OR EXHAUST PIPE, AND DON,T FORGET TO PURGE THE BACK GAS WHEN WELDING ,and if you shop for components carefully youll find that a stainless exhaust will cost only slightly more than the muffler shop charges for inferior aluminized steel
if your going thru the work do it correctly, buy and install decent components so your not back doing it again in a year or so!
BUT THEN I ONLY BUY AND INSTALL STAINLESS COMPONENTS IF GIVEN AN OPTION, INSTALL THEM MYSELF, AND CAN,T REMEMBER HAVING PROBLEMS INSTALLING OR HAVING A COMPONENT FAIL IF ITS PROPERLY INSTALLED...QUALITY EXHAUST HANGERS DON,T GENERALLY FAIL AND QUALITY WELDS DON,T GENERALLY BREAK, AND IF YOU INSTALL IN CORRECTLY YOURSELF AND CAN WELD YOULL SAVE MONEY AND HAVE THE EQUIPMENT AND SKILL TO FIX IT IN THE UNLIKELY EVENT IT DID BREAK
JUST ONE MORE REASON TO LEARN TO WELD AND HAVE ACCESS TO A GOOD MIG,TIG, OR OXY-ACETOLENE TORCH
theres plenty of fluid dynamics math and research out there to show that the distances the exhaust travels between exhaust pulses and the diam. and length are easily calculated, and past that length the second previous pulse has little effect compared to the current and previous pulse energy and reflective wave
and lets not forget the cam timing displacement and intake port all effect the cylinder scavaging the headers can effectively provide also
http://www.engr.colostate.edu/~allan/fluids/page7/PipeLength/pipe.html
http://www.rbracing-rsr.com/runnertorquecalc.html
http://victorylibrary.com/mopar/header-tech-c.htm
http://www.headerdesign.com/
http://www.pontiacracing.net/js_header_length1.htm
http://www.slowgt.com/Calc2.htm#Header
example , my 383 vette has a cam with exhaust cam timing that opens at 83degs bbdc, thats 97 degs atdc, http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=119661&lvl=2&prt=5
Bore: (Inches) 4.03"<BR>Exhaust Valve Opening Point: (Degrees ATDC) 97 degs
Peak Power RPM: 5500rpm Calculated information appears below
Header Pipe Diameter: (Inches) 1.84"<
Header Pipe Length: (Inches) 37.65
Collector Diameter: (Inches) 3.5
Collector Length: (Inches) 18.82
so ideally the (X) is placed at that point to maximize scavaging but thats not always possiable due to clearance, and if you choose to place an (H) just before the mufflers its mostly to reduce resonance or noise not increase scavaging but it tends to reduce the restriction to flow
most guys I talk and deal with,seem to think that slapping a set of headers on thier car is all thats required to boost performance....ANY HEADERS! ...and they fail to realize that both the header design and the exhaust system behind them require a good deal of thought if you want the maximum benefits, and that simply hooking a restrictive exhaust system to the collectors on the best headers will negate most of thier potential benefits.
most commercial headers are designed mostly for ease of manufacturing and ease of installation,little thought goes into maximizing the cylinder scavaging which is thier main function.
your fooling yourself if you think headers will provide a big boost in hp/tq without the low restriction exhaust behind them,and in most cases that requires a larger dia. exhaust system and adding an (X) to the system and extending the header collectors at thier full dia. up till at least the exit of the (X) so the twin exhaust pipes cross sectional area can provide that reduced restriction to flow, rather than the reducers many guys install to the collector exits to adapt them to the stock exhaust system
http://garage.grumpysperformance.com/index.php?threads/a-well-designed-c4-exhaust.786/
example of a well laid out exhaust (MELROSE)
but even that system could be hurt if you slap restrictive mufflers on it
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