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  • Users: stingc
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  1. stingc

    Engine throttle/resistance question

    As everyone has said, all of this is very hard to do from first principles. Even looking up data (much beyond what you've already done) would probably be hard. I'd try actually driving some cars to see how they react. Every car I've ever driven has a very noticeably nonlinear throttle response...
  2. stingc

    Rear Leaf springs

    Corvettes have had single leaf springs for many years (transversely mounted). They're made out of some composite material, so they're actually much lighter than the equivalent multileaf metal spring.
  3. stingc

    Gear ratio vs powerband

    You're the one who said the higher gears don't work at the strip. If I put in really sticky tires in the program, then higher gears do improve ET's. Another thing is that if the car is launched very softly -- just feather the clutch off idle -- then higher gears improve your times also (but...
  4. stingc

    Gear ratio vs powerband

    I have a program which calculates 1/4 mile times etc. I looked up the 03 viper specs, found someone's dyno printout, and saw what it gave me. I obviously have to make some unknown tire and driver reaction assumptions, but the changes are what's important. Baseline w/3.07: 0-60: 3.9 0-100: 8.6...
  5. stingc

    Force in the springs after a jump

    The characteristic angular frequency of a spring-mass system is sqrt(k/m), where k is the spring constant and m is the (sprung) mass. The quick and dirty answer to your question is therefore: Favg=(momentum change)/(time change)=dp/dt dt=2pi*sqrt(m/k)=0.3 s dp=M*v=M*sqrt(2gh)=7000 kg m/s...
  6. stingc

    Drivetrain Loss

    Greg, Where would one look to find documents like that? I'm not an engineer, so I don't know the usual sources. Thanks.
  7. stingc

    Drivetrain Loss

    Are you saying that the temperature significantly affects the losses, or just that all the extra torque causes more gear friction (and therefore heat)? If its the first one, are diff coolers therefore useful for improving power even if not required for reliability?
  8. stingc

    Solar Sails - may not work

    Yes, a stationary sail will be accelerated. The Doppler shift I'm talking about is the incremental one from the velocity picked up just after an absorbtion. Another way of looking at this is that all of a photon's momentum can be an absorbed by a massive object. Its energy, however, cannot all...
  9. stingc

    Solar Sails - may not work

    Greg, I reread your post, and I guess I answered something you didn't ask :) Anyways, the photons do not have exactly the same frequency before and after. Reflection is an absorbtion/reemission process, so the the emitted photons will be Doppler shifted.
  10. stingc

    Solar Sails - may not work

    The system includes the sun. That's where the energy comes from.
  11. stingc

    Solar Sails - may not work

    I think he's going senile. There's some odd statements in his argument. He's first assuming that a mirror does not allow redshifts. That makes no sense. Then he talks about an aborbing object ceasing to absorb energy once its heated up. That's not true. An object in thermal equilibrium emits...
  12. stingc

    6-Speed Automatic Idea: Electromagnetic Clutches

    Interesting idea, but I think the currents and coil sizes required would be prohibitive. It would require either massive currents and/or a lot of lever arm or hydraulic mechanisms. And it would still need lubrication as EdDanzer stated above (same as manual transmission).
  13. stingc

    7 Speed Automatic Transmission

    I think this is actually useful, but not for fuel economy. The top Mercedes are now being sold as luxury cars that are also speed demons. Gear ratios would usually be selected very differently for those two applications. Lets look at the design requirements: Shift and cruise at low rpm...

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