robinairtechsupport
Automotive
constantly variable length intake runners...
just bouncing ideas around at this point, as i am in no position to begin production on anything at this point, though i may build several prototype units to fool around with. my idea is this... individual throttle body setup with constantly variable length intake runners, to change runner length/volume/tune per rpms, as well as possibly several other factors, such as a/fr, timing, load, and possibly even boost, while driving.
to the best of my knowledge, there are several ways to do this that make sense to me. i believe at least one, if not all have basically been done, by people who are obviously more experienced and intelligent than myself, and seeing as most people on here have intrigued me since i found this forum, i would like some oppinions, as well as some help. as i said, this is probably not an origional iadea, but has probably not been produced for a variety of reasons, probably cost, as well as packaging and reliability concerns. i would like to learn from other people's mistakes. it saves time...
so... hydraulic, electronic, automatronics, mechanical, automotive, fluid dynamics... i am a 20 yr old fabricator with hopes of going to school some day, but these are not my areas of expertise. i work as technical support for a company that does a/c equipment, but on my time i build vehicles. engine and driveline swaps, roll cages, frames, custom exhaust, turbo kits, tuning,
suspension, and r&d for backyard racecars.
a tuned itb intake is a great, but lift changes w/vtec, and optimal length and volume changes w/ rpm.and a fixed length runner system needs to be a compromise between high rpm, low range torque, and idle quality, with the characteristis of one taking away from the others, therefore making tuning into compromization. i like the throttle response, power, and pure coolness factor of the itb setup, but honda, as well asother manufacturers did design and build dual runner intakes, albeit w/ a restrictive butterfly plate setup, a common plenum, and imperfect flow paths, but probably only because of the damn bean counters.this is a great iadea, but not well suited to a race engine. i'm not trying to make a super amount of power, not looking for miracles, just the ability to have the optimal tune at all times, with the least restrictive system possible, to make use of other modifications to that glorified air pump we call a motor. need iadeas, want to share, and explore options.
basically, a conventional cable throttle with mechanically synchronised linkages through a common single cable would be hard, since i am trying to make them[the throttle bodies, not the butterflies] move possibly individually throttle butterfly would be actuated either electronically, with actuators connected to a variable voltage output from the throttle pedal, or mechanically, with a split cable system comparable to what splits brake cables on a bycicle, (1-2, 2-4)giving each assembly adequate travel, wich would be easier, though slightly less acurate. i have the concept figured out pretty much, and i have several actuation systems in mind to change the length of the runners...
the best, least restrictive method of changing the port length i can come up with being to slide a "middle tube", encased between an "inner" tube, being as thin as possible, and chamfered for flow, and an "outer" tube, for strength. the middle tube being attached to the throttle body, and the inner and outer attatched to the head.
object being to account for differences in port design on the head, air requirements, fuel requirements, etc. and possibly monitor throttle position, a/f ratio, intake and exhaust temp, map, (and possibly boost) on each cylinder individually, and feed those values into a program to produce x, x being a specific voltage as per that specific set of variables, specific to that cylinder, with x being fed into a set of actuators to lengthen or shorten the runner,controlled by x.
the throttle body/runner would be at the maximum allowable angle to match the port in the head, addressing flow concerns, while still considering packaging. i figure that with 6 inch(approx) tubes, i could vary effective runner length from (aprox)9-15 inches (about 3" from face of head to top of valve) to make use of that elusive "n/a boost" effect produced by catching the pressure waves at the right time.
one approach being electric/hydraulic, with a hydraulic pump driven by the motor, connected to a series of variable lift solenoids or regulators electronically controlled by x, feeding a system of small hydraulic cylinders with a return line connected through a specified sized "jet" (for lack of a better word.) to let fluid bybass into the return line at low pressure. with controllable flow solenoids, it would be possible to use an electronic Blight springs would hold the tubes in the "closed", or short position, untill pressure was allowed to build, forcing the cylinders to "open" the runners, or make them longer. the cylinders would actuate at least two points on each runner, to eliminate binding, but the system could also be controlled by just hydraulic pressure based on how fast the pump spins by sizing the return orifice to hold back 1 pound of pressure at idle, w/ a 2 pound spring threshold, and then the blockage created would hold back flow and create pressure in relation to pump speed, wich is proportional to rpm...
another option being to control the system electronically, wich will probably be the way i'll go with electronic actuators, controlled directly by x, wich could slide the assembly as well.
please: feedback. thank you. also, please don't patent my idea. its probably not that good, rather expensive, and i'd hate to build one, and have someone confiscate it because someone else patented my project. thoughts, ideas, and information should be shared, discussed, not hoarded. technological advancement is dependant on communication. i don't know anyone who can even remotely understand what i am talking about, let alone the principles behind why it would work. so this is my last hope. am i an idiot? or just smarter than southwestern pennsylvania? i bet im an idiot. let me know.
also, as a final word... something that has always stuck with me: it takes hundreds of engineers thousands of hours to design a car. what makes me think i have a better idea?thats what everyone always tells me, and for the most part, its true... but the thing is, what is the car designed for? oem designs for economy, cost, emissions, fuel efficiency, market trends, etc. i dont care about any of that. loud, smelly, expensive, complicated, high-maintenance, ipmpactical, i dont care, as long as its fast and fun. i build other ppl's junk, b/c i cant afford to buy new. i'd rather spend hours and hours building something than to buy it new. even if thiers works better, i'll cut and weld till i get it right. works for me. thanx... ADI
just bouncing ideas around at this point, as i am in no position to begin production on anything at this point, though i may build several prototype units to fool around with. my idea is this... individual throttle body setup with constantly variable length intake runners, to change runner length/volume/tune per rpms, as well as possibly several other factors, such as a/fr, timing, load, and possibly even boost, while driving.
to the best of my knowledge, there are several ways to do this that make sense to me. i believe at least one, if not all have basically been done, by people who are obviously more experienced and intelligent than myself, and seeing as most people on here have intrigued me since i found this forum, i would like some oppinions, as well as some help. as i said, this is probably not an origional iadea, but has probably not been produced for a variety of reasons, probably cost, as well as packaging and reliability concerns. i would like to learn from other people's mistakes. it saves time...
so... hydraulic, electronic, automatronics, mechanical, automotive, fluid dynamics... i am a 20 yr old fabricator with hopes of going to school some day, but these are not my areas of expertise. i work as technical support for a company that does a/c equipment, but on my time i build vehicles. engine and driveline swaps, roll cages, frames, custom exhaust, turbo kits, tuning,
suspension, and r&d for backyard racecars.
a tuned itb intake is a great, but lift changes w/vtec, and optimal length and volume changes w/ rpm.and a fixed length runner system needs to be a compromise between high rpm, low range torque, and idle quality, with the characteristis of one taking away from the others, therefore making tuning into compromization. i like the throttle response, power, and pure coolness factor of the itb setup, but honda, as well asother manufacturers did design and build dual runner intakes, albeit w/ a restrictive butterfly plate setup, a common plenum, and imperfect flow paths, but probably only because of the damn bean counters.this is a great iadea, but not well suited to a race engine. i'm not trying to make a super amount of power, not looking for miracles, just the ability to have the optimal tune at all times, with the least restrictive system possible, to make use of other modifications to that glorified air pump we call a motor. need iadeas, want to share, and explore options.
basically, a conventional cable throttle with mechanically synchronised linkages through a common single cable would be hard, since i am trying to make them[the throttle bodies, not the butterflies] move possibly individually throttle butterfly would be actuated either electronically, with actuators connected to a variable voltage output from the throttle pedal, or mechanically, with a split cable system comparable to what splits brake cables on a bycicle, (1-2, 2-4)giving each assembly adequate travel, wich would be easier, though slightly less acurate. i have the concept figured out pretty much, and i have several actuation systems in mind to change the length of the runners...
the best, least restrictive method of changing the port length i can come up with being to slide a "middle tube", encased between an "inner" tube, being as thin as possible, and chamfered for flow, and an "outer" tube, for strength. the middle tube being attached to the throttle body, and the inner and outer attatched to the head.
object being to account for differences in port design on the head, air requirements, fuel requirements, etc. and possibly monitor throttle position, a/f ratio, intake and exhaust temp, map, (and possibly boost) on each cylinder individually, and feed those values into a program to produce x, x being a specific voltage as per that specific set of variables, specific to that cylinder, with x being fed into a set of actuators to lengthen or shorten the runner,controlled by x.
the throttle body/runner would be at the maximum allowable angle to match the port in the head, addressing flow concerns, while still considering packaging. i figure that with 6 inch(approx) tubes, i could vary effective runner length from (aprox)9-15 inches (about 3" from face of head to top of valve) to make use of that elusive "n/a boost" effect produced by catching the pressure waves at the right time.
one approach being electric/hydraulic, with a hydraulic pump driven by the motor, connected to a series of variable lift solenoids or regulators electronically controlled by x, feeding a system of small hydraulic cylinders with a return line connected through a specified sized "jet" (for lack of a better word.) to let fluid bybass into the return line at low pressure. with controllable flow solenoids, it would be possible to use an electronic Blight springs would hold the tubes in the "closed", or short position, untill pressure was allowed to build, forcing the cylinders to "open" the runners, or make them longer. the cylinders would actuate at least two points on each runner, to eliminate binding, but the system could also be controlled by just hydraulic pressure based on how fast the pump spins by sizing the return orifice to hold back 1 pound of pressure at idle, w/ a 2 pound spring threshold, and then the blockage created would hold back flow and create pressure in relation to pump speed, wich is proportional to rpm...
another option being to control the system electronically, wich will probably be the way i'll go with electronic actuators, controlled directly by x, wich could slide the assembly as well.
please: feedback. thank you. also, please don't patent my idea. its probably not that good, rather expensive, and i'd hate to build one, and have someone confiscate it because someone else patented my project. thoughts, ideas, and information should be shared, discussed, not hoarded. technological advancement is dependant on communication. i don't know anyone who can even remotely understand what i am talking about, let alone the principles behind why it would work. so this is my last hope. am i an idiot? or just smarter than southwestern pennsylvania? i bet im an idiot. let me know.
also, as a final word... something that has always stuck with me: it takes hundreds of engineers thousands of hours to design a car. what makes me think i have a better idea?thats what everyone always tells me, and for the most part, its true... but the thing is, what is the car designed for? oem designs for economy, cost, emissions, fuel efficiency, market trends, etc. i dont care about any of that. loud, smelly, expensive, complicated, high-maintenance, ipmpactical, i dont care, as long as its fast and fun. i build other ppl's junk, b/c i cant afford to buy new. i'd rather spend hours and hours building something than to buy it new. even if thiers works better, i'll cut and weld till i get it right. works for me. thanx... ADI
