potatoe in exhaust sciene (bernoulli effect) ?
Discussion
mighty car mods did a somewhat joke peice where they stuck/floated a rounded potatoe in the cars exhaust and gained some bhp on the dyno.
about 4-5% across the whole rev range.....which is nothing to sniff at.
ive been looking into why it may of worked in reducing backpressure, and ive come across the science experiment where you can blow into a cone/funnel and it sucks a ping pong ball back into the cone in instead of blowing it out.
why the above experiment works is as the air goes round the ping pong ball it speeds up...creating low pressure air and this suction is pulling the ball in.
somthing to do with the bernoulli effect and the coanda effect....im not smart enough to get too deep into it.
my thoughts are, if you could suspend a ball (potatoe) at the right position at the exit of the exhaust, it too creates this low pressure section around the ball, creating a vacuum which sucks the exhaust gasses out better, reducing backpressure.
ive tried with a funnel and a long tube i use to fill my pc water cooling....and i can notice a drop in blown pressure (my lungs) if a get my finger in the funnel at the correct position.
another wierd thing....my mate put one of those silly car turbo whistles on my exhaust.....didnt make a noise. i only noticed it after a week as i saw it.
again, no noise....but i did notice some "pep/responsiveness" had gone after removing it. this too places a roundish object in the centre of the exhaust exit path (and my exhust tip is a slight internal cone shape)
thoughts on all the above?
about 4-5% across the whole rev range.....which is nothing to sniff at.
ive been looking into why it may of worked in reducing backpressure, and ive come across the science experiment where you can blow into a cone/funnel and it sucks a ping pong ball back into the cone in instead of blowing it out.
why the above experiment works is as the air goes round the ping pong ball it speeds up...creating low pressure air and this suction is pulling the ball in.
somthing to do with the bernoulli effect and the coanda effect....im not smart enough to get too deep into it.
my thoughts are, if you could suspend a ball (potatoe) at the right position at the exit of the exhaust, it too creates this low pressure section around the ball, creating a vacuum which sucks the exhaust gasses out better, reducing backpressure.
ive tried with a funnel and a long tube i use to fill my pc water cooling....and i can notice a drop in blown pressure (my lungs) if a get my finger in the funnel at the correct position.
another wierd thing....my mate put one of those silly car turbo whistles on my exhaust.....didnt make a noise. i only noticed it after a week as i saw it.
again, no noise....but i did notice some "pep/responsiveness" had gone after removing it. this too places a roundish object in the centre of the exhaust exit path (and my exhust tip is a slight internal cone shape)
thoughts on all the above?
jimmyhackers said:
mighty car mods did a somewhat joke peice where they stuck/floated a rounded potatoe in the cars exhaust and gained some bhp on the dyno.
about 4-5% across the whole rev range.....which is nothing to sniff at.
ive been looking into why it may of worked in reducing backpressure, and ive come across the science experiment where you can blow into a cone/funnel and it sucks a ping pong ball back into the cone in instead of blowing it out.
why the above experiment works is as the air goes round the ping pong ball it speeds up...creating low pressure air and this suction is pulling the ball in.
somthing to do with the bernoulli effect and the coanda effect....im not smart enough to get too deep into it.
my thoughts are, if you could suspend a ball (potatoe) at the right position at the exit of the exhaust, it too creates this low pressure section around the ball, creating a vacuum which sucks the exhaust gasses out better, reducing backpressure.
ive tried with a funnel and a long tube i use to fill my pc water cooling....and i can notice a drop in blown pressure (my lungs) if a get my finger in the funnel at the correct position.
another wierd thing....my mate put one of those silly car turbo whistles on my exhaust.....didnt make a noise. i only noticed it after a week as i saw it.
again, no noise....but i did notice some "pep/responsiveness" had gone after removing it. this too places a roundish object in the centre of the exhaust exit path (and my exhust tip is a slight internal cone shape)
thoughts on all the above?
Snake oil.about 4-5% across the whole rev range.....which is nothing to sniff at.
ive been looking into why it may of worked in reducing backpressure, and ive come across the science experiment where you can blow into a cone/funnel and it sucks a ping pong ball back into the cone in instead of blowing it out.
why the above experiment works is as the air goes round the ping pong ball it speeds up...creating low pressure air and this suction is pulling the ball in.
somthing to do with the bernoulli effect and the coanda effect....im not smart enough to get too deep into it.
my thoughts are, if you could suspend a ball (potatoe) at the right position at the exit of the exhaust, it too creates this low pressure section around the ball, creating a vacuum which sucks the exhaust gasses out better, reducing backpressure.
ive tried with a funnel and a long tube i use to fill my pc water cooling....and i can notice a drop in blown pressure (my lungs) if a get my finger in the funnel at the correct position.
another wierd thing....my mate put one of those silly car turbo whistles on my exhaust.....didnt make a noise. i only noticed it after a week as i saw it.
again, no noise....but i did notice some "pep/responsiveness" had gone after removing it. this too places a roundish object in the centre of the exhaust exit path (and my exhust tip is a slight internal cone shape)
thoughts on all the above?
Placebo effect.
Is it still half-term?
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