monstar
Naturally as-pirated
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- Peugeot 207 GTi
I use PipeMax software to design headers and exhausts, here's some useful tidbits to consider when choosing an exhaust for a near stock LS3:
304 kW LS3
Cylinder Ignition Interval = 90 degrees Peak HP @ 5700 RPM Hertz frequency = 47.5 Hz
Target EGT= 1364.4 degrees F at end of 4 second 600 RPM/Sec Dyno accel. test
376.053 CID Exhaust System operating RPM Range from 3700 to 6200 RPM
4-2-1 (Tri-Y)
--- 2-Step Equal Segment Length TRI-Y --- ( Low to MidRange RPM TQ and HP )
1st Y-Segment Dia. inches= 1.500 Length= 14.9 to 16.4 inches long
2nd Y-Segment Dia. inches= 1.625 Length= 14.9 to 16.4 inches long
Combined Total of all Segment Lengths= 29.8 to 32.7 inches long
--- 3-Step TRI-Y Specs --- ( Low to Mid-Range Torque and Hi RPM HP )
1st Y-Segment 1st Step Dia. inches= 1.500 Length= 14.9 to 16.4
1st Y-Segment 2nd Step Dia. inches= 1.625 Length= 7.5 to 8.2
2nd Y-Segment 3rd Step Dia. inches= 1.750 Length= 7.5 to 8.2
Combined Total of all Segment Lengths= 29.8 to 32.7 inches long
--- 3-Step TRI-Y Pipe Specs --- ( Higher RPM Horsepower, possible TQ loss )
1st Y-Segment 1st Step Dia. inches= 1.625 Length= 14.9 to 16.4
1st Y-Segment 2nd Step Dia. inches= 1.750 Length= 7.5 to 8.2
2nd Y-Segment 3rd Step Dia. inches= 1.875 Length= 7.5 to 8.2
Combined Total of all Segment Lengths= 29.8 to 32.7 inches long
--- Megaphone Collector Specs ---( Diffuser or Diverging Cone Shape )---
( TQ ) Diameter= 1.962 taper to 2.962 Best Length= 18.7 or 37.3 inches
( HP ) Diameter= 2.212 taper to 3.212 Best Length= 18.7 or 37.3 inches
H-Pipe= 18.7 X-Pipe= 74.7 distance behind end of Primary Tube ends
Best HP/TQ Tuned Collector Lengths= 18.7 , 37.3 , 74.7 , 149.3 inches long
Worst HP/TQ Loss Collector Lengths= 28.0 , 56.0 , 112.0 , 224.0 inches long
Note-> all Pipe Diameters are OD and based-off .0625 inch Pipe thickness
---- Collector's Harmonics (includes Intermediate, Muffler , TailPipe) ----
1st Harmonic = 149.3 inches long ... longest with Mufflers and TailPipes
2nd Harmonic = 74.7 inches long ... longest recommended with Mufflers
3rd Harmonic = 37.3 inches long ... more bottom-end Torque
4th Harmonic = 18.7 inches long ... highly recommended , best Torque Curve
5th Harmonic = 9.3 inches long ... reduced Torque , more top-end HP sometimes
6th Harmonic = 4.7 inches long ... reduced Torque , not recommended
4-1 (Straight)
--- Single Primary Pipe Specs --- ( Low to Mid-Range RPM Torque and HP )
Diameter= 1.563 to 1.688 Total Length= 29.8 to 32.7 inches long
--- 2-Step Primary Pipe Specs --- ( Low to Mid-Range RPM Torque and HP )
1st Step Dia. inches= 1.563 Length= 14.9 to 16.4
2nd Step Dia. inches= 1.688 Length= 14.9 to 16.4
--- 3-Step Primary Pipe Specs --- ( Low to Mid-Range Torque and Hi RPM HP )
1st Step Dia. inches= 1.563 Length= 14.9 to 16.4
2nd Step Dia. inches= 1.688 Length= 7.5 to 8.2
3rd Step Dia. inches= 1.813 Length= 7.5 to 8.2
--- Single Primary Pipe Specs --- ( Mid-Range TQ to Higher RPM Horsepower )
Diameter= 1.763 to 1.888 Total Length= 29.8 to 32.7 inches long
--- 2-Step Primary Pipe Specs --- ( Mid-Range TQ to Higher RPM Horsepower )
1st Step Dia. inches= 1.763 Length= 9.9 to 11.4
2nd Step Dia. inches= 1.888 Length= 19.9 to 21.3
--- 3-Step Primary Pipe Specs --- ( Higher RPM Horsepower, possible TQ loss )
1st Step Dia. inches= 1.763 Length= 9.9 to 11.4
2nd Step Dia. inches= 1.888 Length= 9.9 to 10.7
3rd Step Dia. inches= 2.013 Length= 9.9 to 10.7
--- Conventional Straight Tube Collector Specs ---
( TQ ) Diameter= 2.837 to 3.087 Best Length= 18.7 and also 37.3 inches
( HP ) Diameter= 3.087 to 3.587 Best Length= 18.7 and also 9.3 inches
--- Megaphone Collector Specs ---( Diffuser or Diverging Cone Shape )---
( TQ ) Diameter= 2.087 taper to 3.087 Best Length= 18.7 or 37.3 inches
( HP ) Diameter= 2.337 taper to 3.337 Best Length= 18.7 or 37.3 inches
H-Pipe= 18.7 X-Pipe= 74.7 distance behind end of Primary Tube ends
-- Total Exhaust System Tuned Lengths (Primary ends to TailPipe end) --
Best HP/TQ Tuned Collector Lengths= 18.7 , 37.3 , 74.7 , 149.3 inches long
Worst HP/TQ Loss Collector Lengths= 28.0 , 56.0 , 112.0 , 224.0 inches long
Note=> measured from where the Primary Pipes end inside the Collector to
the point the Collector or tailpipe exits into the atmosphere.
Note-> all Pipe Diameters are OD and based-off .0625 inch Pipe thickness
---- Primary Pipe's Harmonics ----
1st Harmonic = 131.9 inches long ... typically never used
2nd Harmonic = 49.9 inches long ... longest recommended
3rd Harmonic = 29.8 inches long ... highly recommended , best Torque Curve
4th Harmonic = 20.8 inches long ... shortest recommended
5th Harmonic = 15.6 inches long ... typically never used
6th Harmonic = 12.2 inches long ... typically never used
7th Harmonic = 9.9 inches long ... typically never used
8th Harmonic = 8.2 inches long ... typically never used
---- Collector's Harmonics (includes Intermediate, Muffler , TailPipe) ----
1st Harmonic = 149.3 inches long ... longest with Mufflers and TailPipes
2nd Harmonic = 74.7 inches long ... longest recommended with Mufflers
3rd Harmonic = 37.3 inches long ... more bottom-end Torque
4th Harmonic = 18.7 inches long ... highly recommended , best Torque Curve
5th Harmonic = 9.3 inches long ... reduced Torque , more top-end HP sometimes
6th Harmonic = 4.7 inches long ... reduced Torque , not recommended
304 kW LS3
Cylinder Ignition Interval = 90 degrees Peak HP @ 5700 RPM Hertz frequency = 47.5 Hz
Target EGT= 1364.4 degrees F at end of 4 second 600 RPM/Sec Dyno accel. test
376.053 CID Exhaust System operating RPM Range from 3700 to 6200 RPM
4-2-1 (Tri-Y)
--- 2-Step Equal Segment Length TRI-Y --- ( Low to MidRange RPM TQ and HP )
1st Y-Segment Dia. inches= 1.500 Length= 14.9 to 16.4 inches long
2nd Y-Segment Dia. inches= 1.625 Length= 14.9 to 16.4 inches long
Combined Total of all Segment Lengths= 29.8 to 32.7 inches long
--- 3-Step TRI-Y Specs --- ( Low to Mid-Range Torque and Hi RPM HP )
1st Y-Segment 1st Step Dia. inches= 1.500 Length= 14.9 to 16.4
1st Y-Segment 2nd Step Dia. inches= 1.625 Length= 7.5 to 8.2
2nd Y-Segment 3rd Step Dia. inches= 1.750 Length= 7.5 to 8.2
Combined Total of all Segment Lengths= 29.8 to 32.7 inches long
--- 3-Step TRI-Y Pipe Specs --- ( Higher RPM Horsepower, possible TQ loss )
1st Y-Segment 1st Step Dia. inches= 1.625 Length= 14.9 to 16.4
1st Y-Segment 2nd Step Dia. inches= 1.750 Length= 7.5 to 8.2
2nd Y-Segment 3rd Step Dia. inches= 1.875 Length= 7.5 to 8.2
Combined Total of all Segment Lengths= 29.8 to 32.7 inches long
--- Megaphone Collector Specs ---( Diffuser or Diverging Cone Shape )---
( TQ ) Diameter= 1.962 taper to 2.962 Best Length= 18.7 or 37.3 inches
( HP ) Diameter= 2.212 taper to 3.212 Best Length= 18.7 or 37.3 inches
H-Pipe= 18.7 X-Pipe= 74.7 distance behind end of Primary Tube ends
Best HP/TQ Tuned Collector Lengths= 18.7 , 37.3 , 74.7 , 149.3 inches long
Worst HP/TQ Loss Collector Lengths= 28.0 , 56.0 , 112.0 , 224.0 inches long
Note-> all Pipe Diameters are OD and based-off .0625 inch Pipe thickness
---- Collector's Harmonics (includes Intermediate, Muffler , TailPipe) ----
1st Harmonic = 149.3 inches long ... longest with Mufflers and TailPipes
2nd Harmonic = 74.7 inches long ... longest recommended with Mufflers
3rd Harmonic = 37.3 inches long ... more bottom-end Torque
4th Harmonic = 18.7 inches long ... highly recommended , best Torque Curve
5th Harmonic = 9.3 inches long ... reduced Torque , more top-end HP sometimes
6th Harmonic = 4.7 inches long ... reduced Torque , not recommended
4-1 (Straight)
--- Single Primary Pipe Specs --- ( Low to Mid-Range RPM Torque and HP )
Diameter= 1.563 to 1.688 Total Length= 29.8 to 32.7 inches long
--- 2-Step Primary Pipe Specs --- ( Low to Mid-Range RPM Torque and HP )
1st Step Dia. inches= 1.563 Length= 14.9 to 16.4
2nd Step Dia. inches= 1.688 Length= 14.9 to 16.4
--- 3-Step Primary Pipe Specs --- ( Low to Mid-Range Torque and Hi RPM HP )
1st Step Dia. inches= 1.563 Length= 14.9 to 16.4
2nd Step Dia. inches= 1.688 Length= 7.5 to 8.2
3rd Step Dia. inches= 1.813 Length= 7.5 to 8.2
--- Single Primary Pipe Specs --- ( Mid-Range TQ to Higher RPM Horsepower )
Diameter= 1.763 to 1.888 Total Length= 29.8 to 32.7 inches long
--- 2-Step Primary Pipe Specs --- ( Mid-Range TQ to Higher RPM Horsepower )
1st Step Dia. inches= 1.763 Length= 9.9 to 11.4
2nd Step Dia. inches= 1.888 Length= 19.9 to 21.3
--- 3-Step Primary Pipe Specs --- ( Higher RPM Horsepower, possible TQ loss )
1st Step Dia. inches= 1.763 Length= 9.9 to 11.4
2nd Step Dia. inches= 1.888 Length= 9.9 to 10.7
3rd Step Dia. inches= 2.013 Length= 9.9 to 10.7
--- Conventional Straight Tube Collector Specs ---
( TQ ) Diameter= 2.837 to 3.087 Best Length= 18.7 and also 37.3 inches
( HP ) Diameter= 3.087 to 3.587 Best Length= 18.7 and also 9.3 inches
--- Megaphone Collector Specs ---( Diffuser or Diverging Cone Shape )---
( TQ ) Diameter= 2.087 taper to 3.087 Best Length= 18.7 or 37.3 inches
( HP ) Diameter= 2.337 taper to 3.337 Best Length= 18.7 or 37.3 inches
H-Pipe= 18.7 X-Pipe= 74.7 distance behind end of Primary Tube ends
-- Total Exhaust System Tuned Lengths (Primary ends to TailPipe end) --
Best HP/TQ Tuned Collector Lengths= 18.7 , 37.3 , 74.7 , 149.3 inches long
Worst HP/TQ Loss Collector Lengths= 28.0 , 56.0 , 112.0 , 224.0 inches long
Note=> measured from where the Primary Pipes end inside the Collector to
the point the Collector or tailpipe exits into the atmosphere.
Note-> all Pipe Diameters are OD and based-off .0625 inch Pipe thickness
---- Primary Pipe's Harmonics ----
1st Harmonic = 131.9 inches long ... typically never used
2nd Harmonic = 49.9 inches long ... longest recommended
3rd Harmonic = 29.8 inches long ... highly recommended , best Torque Curve
4th Harmonic = 20.8 inches long ... shortest recommended
5th Harmonic = 15.6 inches long ... typically never used
6th Harmonic = 12.2 inches long ... typically never used
7th Harmonic = 9.9 inches long ... typically never used
8th Harmonic = 8.2 inches long ... typically never used
---- Collector's Harmonics (includes Intermediate, Muffler , TailPipe) ----
1st Harmonic = 149.3 inches long ... longest with Mufflers and TailPipes
2nd Harmonic = 74.7 inches long ... longest recommended with Mufflers
3rd Harmonic = 37.3 inches long ... more bottom-end Torque
4th Harmonic = 18.7 inches long ... highly recommended , best Torque Curve
5th Harmonic = 9.3 inches long ... reduced Torque , more top-end HP sometimes
6th Harmonic = 4.7 inches long ... reduced Torque , not recommended