3 ms·

No, having a long pipe impacts performance as it puts back pressure on the engine.

by jsjohnst 9y ago

agumonkey 9y ago
Some resistance like concept for fluids ?
- jerf 9y ago
  A manifestation of drag: https://en.wikipedia.org/wiki/Drag_(physics) https://en.wikipedia.org/wiki/Drag_(physics) Stuff doesn't move through pipes for free. Given that we'd probably have to put tons of turns into this pipe, too, those are even more expensive. Contrary to probably-locally-popular opinion, cars have been engineered to within an inch of their lives, and the quest for better fuel economy has been a huge focus of the industry for decades, pretty much countered only by "customer safety" and "what will the customers pay for". If there was an efficient way to recover the heat, it would probably already be getting used, as evidenced by all the other mechanisms already in a car if you look.
  - agumonkey 9y ago
    I do get all this, but you know very well that "what customers would pay for" is very much contextual and thus "energy economy" is not only a fixed law. I'm sure zero percent of the market cared about pollution or high efficiency in the 90s and today it's a sizeable chunk (Im guessing but I'd bet a dollar it's at least a single digit %). Today having something in that scavenge heat at some cost might be a plausible marketing argument. Back to physics, so pipe are like wires for electrons, some energy will be wasted. But aren't turbo equipped engines using part of the flow to improve the engine fuel quality ? I should search if people try to expand on that. I know Turbos had some issues but I never read in details and this was long ago.
    - jsjohnst 9y ago
      > But aren't turbo equipped engines using part of the flow to improve the engine fuel quality No, turbo is used to force more air into the intake side of the engine. It uses exhaust gas pressure to spin a turbine which is used to compress more air into the cylinder between cycles. That, combined with more fuel to maintain proper balance, gives you increased combustion, thus more power.

No, having a long pipe impacts performance as it puts back pressure on the engine.

agumonkey 9y ago

Some resistance like concept for fluids ?

jerf 9y ago
A manifestation of drag: https://en.wikipedia.org/wiki/Drag_(physics) https://en.wikipedia.org/wiki/Drag_(physics) Stuff doesn't move through pipes for free. Given that we'd probably have to put tons of turns into this pipe, too, those are even more expensive. Contrary to probably-locally-popular opinion, cars have been engineered to within an inch of their lives, and the quest for better fuel economy has been a huge focus of the industry for decades, pretty much countered only by "customer safety" and "what will the customers pay for". If there was an efficient way to recover the heat, it would probably already be getting used, as evidenced by all the other mechanisms already in a car if you look.
- agumonkey 9y ago
  I do get all this, but you know very well that "what customers would pay for" is very much contextual and thus "energy economy" is not only a fixed law. I'm sure zero percent of the market cared about pollution or high efficiency in the 90s and today it's a sizeable chunk (Im guessing but I'd bet a dollar it's at least a single digit %). Today having something in that scavenge heat at some cost might be a plausible marketing argument. Back to physics, so pipe are like wires for electrons, some energy will be wasted. But aren't turbo equipped engines using part of the flow to improve the engine fuel quality ? I should search if people try to expand on that. I know Turbos had some issues but I never read in details and this was long ago.
  - jsjohnst 9y ago
    > But aren't turbo equipped engines using part of the flow to improve the engine fuel quality No, turbo is used to force more air into the intake side of the engine. It uses exhaust gas pressure to spin a turbine which is used to compress more air into the cylinder between cycles. That, combined with more fuel to maintain proper balance, gives you increased combustion, thus more power.