immortal1kon
02-07-2010, 02:25 AM
ok so i have ventured in to building an intake. it all started with the want to build an Arc like bow from my legacy. it developed into wanting to make an intake which will produce the best torque curve from 2-4k
currently my stock gt makes 162@ 4000rpm peak (subarus numbers )
I need some help gathering the right info.
- anyone with a stock gt cylinder head laying around. if you can measure the length in inches from the actual valve head to where it would connect to the intake manifold.
- if anyone can give the general length of an ebay intake, the length of the tube not a straight shot from opening to opening. (as precise as possible)
- any info would be appreciated.
i have worked out some formulas which helped me conclude that the stock setup from the valve to the throttle body is between 21-22.5inches long. this is aimed at a 4k torque peak. This means that the car will still drive well at 6000rpm but it will have torque below 4k as well.(basically 4k is the factory midpoint at which they developed the car so that it would run its best from 4k+ but still work well under 4k for daily driving.) I have decided to set my mid point at 2k this is because my daily driving requires the most power from 1000-4000RPM max. To improve torque for lower rpms the intake runners of the manifold need to be extended. because this cannot be done easily or cheap by me, i gotto work around it. many have experienced some low end loss when they swap the ebay intake in for their stock. this is because the length is reduced moving the optimum torque range.
thought some say that the hybrid intake works best, i believe thats because the volume of the filter box adds to the length of the intake. The "whale penis" intake for civics gave me a good idea on how to keep a larger area near the throttle body while getting rid of the internal maze and silencers throughout the intake.
more to come as i continue
currently my stock gt makes 162@ 4000rpm peak (subarus numbers )
I need some help gathering the right info.
- anyone with a stock gt cylinder head laying around. if you can measure the length in inches from the actual valve head to where it would connect to the intake manifold.
- if anyone can give the general length of an ebay intake, the length of the tube not a straight shot from opening to opening. (as precise as possible)
- any info would be appreciated.
i have worked out some formulas which helped me conclude that the stock setup from the valve to the throttle body is between 21-22.5inches long. this is aimed at a 4k torque peak. This means that the car will still drive well at 6000rpm but it will have torque below 4k as well.(basically 4k is the factory midpoint at which they developed the car so that it would run its best from 4k+ but still work well under 4k for daily driving.) I have decided to set my mid point at 2k this is because my daily driving requires the most power from 1000-4000RPM max. To improve torque for lower rpms the intake runners of the manifold need to be extended. because this cannot be done easily or cheap by me, i gotto work around it. many have experienced some low end loss when they swap the ebay intake in for their stock. this is because the length is reduced moving the optimum torque range.
thought some say that the hybrid intake works best, i believe thats because the volume of the filter box adds to the length of the intake. The "whale penis" intake for civics gave me a good idea on how to keep a larger area near the throttle body while getting rid of the internal maze and silencers throughout the intake.
more to come as i continue