|  | Topic : Header pipe diameter |  |
| | | sykal | | Set |  |  | | Reg. Date | : | 20/10/2014 | | Posts | : | 52 | | Location | : | W.A, Australia |
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| | Posted : 06 May 2016 - 12:23 Post title : Header pipe diameter | | | Has anyone had any experience with increasing the header pipe diameter, from the head to the mufflers,on a thunderbird storm or big bore kitted tbird?
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4 wheels moves the body
2 wheels moves the soul
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| | | aussietbird | | Set | |  | | Reg. Date | : | 11/09/2012 | | Posts | : | 263 | | Location | : | WODONGA, VIC, Australia |
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| | Posted : 02 Jun 2018 - 07:10 Post title : Re: Header pipe diameter (Re: sykal) | | | Here is what happens.
Increase dia of header pipe, lose in torque, possible gain in horsepower after re-mapping, however this is not a given.
Decrease in dia of header, lose in top end horsepower but possible gains in torque after remapping, again this is not a given.
Experence gained from my old drag bike a already grunty ZRX 1100. removed the 83mm id collector pipe and put in a 50mm id. Lost maybe 15hp at the back wheel, gained some 25flb of torque, with some serious carb tuning and dyno time.
HP may well govern how fast to may hit the wall, however torque governs how far you'll take the wall with you.
Torque is king. And is far more useable in the real world than HP
| The more I understand the human race, the more I love my bike.
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| | | fab | | Thor | |  | | Reg. Date | : | 12/10/2009 | | Posts | : | 2,515 | | Location | : | wyong, nsw, Australia |
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| | Posted : 02 Jun 2018 - 09:28 Post title : Re: Header pipe diameter (Re: aussietbird) | | |
aussietbird wrote:
Here is what happens.
Increase dia of header pipe, lose in torque, possible gain in horsepower after re-mapping, however this is not a given.
Decrease in dia of header, lose in top end horsepower but possible gains in torque after remapping, again this is not a given.
Experence gained from my old drag bike a already grunty ZRX 1100. removed the 83mm id collector pipe and put in a 50mm id. Lost maybe 15hp at the back wheel, gained some 25flb of torque, with some serious carb tuning and dyno time.
HP may well govern how fast to may hit the wall, however torque governs how far you'll take the wall with you.
Torque is king. And is far more useable in the real world than HP |
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Remember, soft cocks hang around all life long, hard ones come and go
ahh f**k im deep
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| | | easyrider | | Thor | |  | | Reg. Date | : | 17/12/2011 | | Posts | : | 2,066 | | Location | : | NSW, Australia |
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| | Posted : 02 Jun 2018 - 23:49 Post title : Re: Header pipe diameter (Re: aussietbird) | | |
aussietbird wrote:
Here is what happens.
Increase dia of header pipe, lose in torque, possible gain in horsepower after re-mapping, however this is not a given.
Decrease in dia of header, lose in top end horsepower but possible gains in torque after remapping, again this is not a given.
Experence gained from my old drag bike a already grunty ZRX 1100. removed the 83mm id collector pipe and put in a 50mm id. Lost maybe 15hp at the back wheel, gained some 25flb of torque, with some serious carb tuning and dyno time.
HP may well govern how fast to may hit the wall, however torque governs how far you'll take the wall with you.
Torque is king. And is far more useable in the real world than HP |
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Larger header pipes with the bike supercharged ? But then i suppose the list will go on eg, heads etc?
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| | | Slcharger | | Jupiter | |  | | Reg. Date | : | 18/02/2016 | | Posts | : | 1,661 | | Location | : | Denmark |
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| | Posted : 04 Jun 2018 - 09:33 Post title : Re: Header pipe diameter (Re: aussietbird) | | |
aussietbird wrote:
Here is what happens.
Increase dia of header pipe, lose in torque, possible gain in horsepower after re-mapping, however this is not a given.
Decrease in dia of header, lose in top end horsepower but possible gains in torque after remapping, again this is not a given.
Experence gained from my old drag bike a already grunty ZRX 1100. removed the 83mm id collector pipe and put in a 50mm id. Lost maybe 15hp at the back wheel, gained some 25flb of torque, with some serious carb tuning and dyno time.
HP may well govern how fast to may hit the wall, however torque governs how far you'll take the wall with you.
Torque is king. And is far more useable in the real world than HP |
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You are right. On a N/A engine you can tune the engine to deliver torque at specified rpm, by changing intake, head ports, valve size and lift, cam timing, exhaust pipe dia. and so on. The scavening and resonans frequency of the system is influenced by the above.
If you use a blower or turbocharger, things are different. As big as possible, all components that flow air, exhaust gasses, minimum flow resistance.
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