Gollum Posted April 10, 2008 Author Share Posted April 10, 2008 Ron, I can take your critisism, no worries. If anything I look forward to it. I'm not looking to pull air from the intake from the exhaust, I'm just wondering what it would take to replicated the design of a well made exhaust system on an ordinary one. Basically, can we acheive good scavenging at all RPM under un-ideal situations? Maybe I'll drop the whole idea, but it'd still be a fun experiment to do. Rig up a 7k+ CFM fan to a tail pipe and compare the dyno results. Even better if it's a restrictive 100% OEM exhaust system. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted April 10, 2008 Share Posted April 10, 2008 The Ferrari FXX uses this principle. They use body aerodynamics to "pull" exahust out of the tailpipes. The tail pipes exit at the rear top edge of the back. Quote Link to comment Share on other sites More sharing options...
G.I.jonas Posted April 10, 2008 Share Posted April 10, 2008 That is way too awesome to look at!! RUN AWAY!!! Quote Link to comment Share on other sites More sharing options...
80LS1T Posted April 10, 2008 Share Posted April 10, 2008 Where are you going to mount a 14" fan onto an exhaust system? Seems to me like it would take up a lot of room and an S30 doesn't have a lot of room to spare as it is. I'm all for more HP but I'm with Ron on this one...I think there are better, easier, more efficient ways to make more power. By all means try it and prove us wrong! Guy Quote Link to comment Share on other sites More sharing options...
MJLamberson Posted May 7, 2008 Share Posted May 7, 2008 A fan the shape of a flashlight... the thinner blades of the fan (the handle of the flashlight) go in the end of the exhaust pipe, the bulb section of the flashlight (still connected to the smaller blades) would stick out the back, and would be a larger blade the the exhaust piping... so as you are driving long the air rushing by is used to spin the blades at the end of the pipe, in turn spinning the blades in the pipe, pulling the exhaust out, that faster you go the harder it pulls. What do you guys think? did I strike a gold mine or make myself look dumb? It would be a restriction when stopped but who cares? Quote Link to comment Share on other sites More sharing options...
Challenger Posted May 7, 2008 Share Posted May 7, 2008 What happens when you let off the throttle? The vacume would be so great it might crack your valves!!! Quote Link to comment Share on other sites More sharing options...
MJLamberson Posted May 7, 2008 Share Posted May 7, 2008 A suck off valve comes to mind Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted May 7, 2008 Share Posted May 7, 2008 A fan the shape of a flashlight... the thinner blades of the fan (the handle of the flashlight) go in the end of the exhaust pipe, the bulb section of the flashlight (still connected to the smaller blades) would stick out the back, and would be a larger blade the the exhaust piping... so as you are driving long the air rushing by is used to spin the blades at the end of the pipe, in turn spinning the blades in the pipe, pulling the exhaust out, that faster you go the harder it pulls. What do you guys think? did I strike a gold mine or make myself look dumb? It would be a restriction when stopped but who cares? you have then created infinite acceleration in a way XP it wouldn't really work the way you're thinking it would. The exhaust causes the smaller fan to spin at X speed, which makes the 2nd fan spin at X speed as well. the problem is, since both of them are moving at the same speed, and are ONLY moving because the exhaust gases are spinning them, there is no way for them to create any suction. If the bigger fan DID start creating enough suction to cause a vacuum onlly because of the smaller fan being spun by the exhaust gases, then it means that the smaller fan is suddenly turning the bigger fan only by the suction created by the bigger fan, which is impossible lol. I'm curious though, as to what something like an ultra high powered vacuum cleaner of some sort could do (if it could suck enough cfm that is) Quote Link to comment Share on other sites More sharing options...
MJLamberson Posted May 7, 2008 Share Posted May 7, 2008 you have then created infinite acceleration in a way XPit wouldn't really work the way you're thinking it would. The exhaust causes the smaller fan to spin at X speed, which makes the 2nd fan spin at X speed as well. the problem is, since both of them are moving at the same speed, and are ONLY moving because the exhaust gases are spinning them, there is no way for them to create any suction. If the bigger fan DID start creating enough suction to cause a vacuum onlly because of the smaller fan being spun by the exhaust gases, then it means that the smaller fan is suddenly turning the bigger fan only by the suction created by the bigger fan, which is impossible lol. I'm curious though, as to what something like an ultra high powered vacuum cleaner of some sort could do (if it could suck enough cfm that is) no no you mis understood, the fan is moving because of the air flow when the car is moving, thats why there is the bigger section the goes beyond the exhaust pipe, so when you drive the air rushing past causes it to spin. so when your going 80mph the fan is being spun by 80mph winds, and it is connected to the fan IN the exhaust pipe so that to would be spining as if it were in 80mph winds, only because that part isnt it would be sucking air out... Its not being spun by exhaust gasses, it is being spun be the air rushing past it do to speed of the car Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted May 7, 2008 Share Posted May 7, 2008 Ohhh I see. well, in that case, I don't think it would work since I really doubt the speed of the car would be sufficient to turn the fan enough RPM's to create enough CFM's to cause enough vacuum in the exhaust to make a difference. Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted May 7, 2008 Share Posted May 7, 2008 I'm curious though, as to what something like an ultra high powered vacuum cleaner of some sort could do (if it could suck enough cfm that is) try takign a Kirby apart and having a engineering firm duplicate the plastic fan in aluminium, the body is already aluminum rather than the typical cleaner plastic, so not much change needed there. I don't know what the emmissions testing people would say if you drove up with a vacuum cleaner bag waving in the breeze behind you tho how much would that clean up the exhaust? Quote Link to comment Share on other sites More sharing options...
Gollum Posted May 7, 2008 Author Share Posted May 7, 2008 I'm curious though, as to what something like an ultra high powered vacuum cleaner of some sort could do (if it could suck enough cfm that is) I'm also still curious. So if I can get some cheap dyno time I'm gonna make a mock rig of some ducting going to a huge 7000cfm+ fan and see if there's any difference on the dyno. I'm betting at most it will be a 5-10% increase from 0-2000 rpm. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted May 7, 2008 Share Posted May 7, 2008 lol this is stupid.. I don't even know why I would type this.. BUT how about a belt driven FAN inside the exhaust that will "suck" air from the engine and "blow" it out the tail pipe. Lets say this belt driven fan is hooked up to the driveshaft?! Higher the speed, faster the air is sucked out Quote Link to comment Share on other sites More sharing options...
MJLamberson Posted May 7, 2008 Share Posted May 7, 2008 lol this is stupid.. I don't even know why I would type this.. BUT how about a belt driven FAN inside the exhaust that will "suck" air from the engine and "blow" it out the tail pipe. Lets say this belt driven fan is hooked up to the driveshaft?! Higher the speed, faster the air is sucked out I reverse supercharger? I could actualy see that working, if a belt driven fan can force air into an engine it should be able to pull it out... but would it be enough of an WHP improvment to be worth it? Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted May 8, 2008 Share Posted May 8, 2008 I can definitely see how this concept would make a bit of increase in power. IF you can get enough vacuum in the exhaust, the cylinders would be under a vacuum, meaning the engine isn't pushing the exhaust out of the cylinder, but the piston is being pulled back up by the force of the vacuum. Hmmm if you had a twice pipe setup hooked up to 2 7000cfm fans, that would increase the overall vacuum and make it better haha Quote Link to comment Share on other sites More sharing options...
Challenger Posted May 8, 2008 Share Posted May 8, 2008 I can definitely see how this concept would make a bit of increase in power. IF you can get enough vacuum in the exhaust, the cylinders would be under a vacuum, meaning the engine isn't pushing the exhaust out of the cylinder, but the piston is being pulled back up by the force of the vacuum. Hmmm if you had a twice pipe setup hooked up to 2 7000cfm fans, that would increase the overall vacuum and make it better haha IF. Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted May 8, 2008 Share Posted May 8, 2008 yeah, really big IF Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted May 8, 2008 Share Posted May 8, 2008 "IF, the biggest word in the English dictionary" Quote Link to comment Share on other sites More sharing options...
Gollum Posted May 8, 2008 Author Share Posted May 8, 2008 I never imagined of gaining HP from pulling the piston up in my oringonal idea... Just optimizing flow. A good set of headers can have a very good increase in power. Tuned headers can have an even bigger increase in power at specific RPMS. My idea was just "how close can we get to the best header design with your average exhaust system, or can we even beat it?" The idea is to NEVER have back pressure, at ALL rpm, allowing the ideal scavenging at all RPM. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 8, 2008 Share Posted May 8, 2008 A suck off valve comes to mind ROFLMAO What's the volume of exhaust compared to the volume of air/fuel taken in? Surely an engine has a ton more cubic feet out than cubic feet in? Quote Link to comment Share on other sites More sharing options...
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