S2kam governer
#11
Registered User
[QUOTE]Originally posted by vananron
[B]Say what you want, but it has been done, don't forget, I am at sea level, in high temp weather, hot air is wayyyy les dense than cold air, less dense = less drag.
[B]Say what you want, but it has been done, don't forget, I am at sea level, in high temp weather, hot air is wayyyy les dense than cold air, less dense = less drag.
#12
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Join Date: Sep 2002
Location: Sacramento
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I understand that the Hp decreases a little, but at such a high speed the drag is way lower. Why do you think that Sacramento Raceway holds a lot of the top fuel dragster records, High heat = better traction, and less dense air for the drag. I do not see very good numbers for drag cars at high altitude. But as you said, it will not attain 167 however it will attain 150!
#13
Originally posted by vananron
But as you said, it will not attain 167 however it will attain 150!
But as you said, it will not attain 167 however it will attain 150!
#18
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You are really fighting air drag tremendously over 100 - it is a square law situation, where a unit of measure increase of speed requires 2X the power. As Xviper eloquently mentioned, there are a ton of factors that can affect top speed "claims". I personally would search the car mags that use precision land-based, photo-optic, or GPS equipment. Or someone ready to go to Bonneville? XViper, jerrypeterson, Bueller, Bueller?
#19
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It is rated for 150MPH and that's about as fast as it will go. The practical top speed is about 135MPH, that is anything above that is going to happen really slowly. I've gotten to 135 on the track and over that on the road but you need a good straight mile or two and a tail wind to get to 150MPH. You can get to 135 pretty quick but acceleration really starts to drop off above that. The MPH's tick off pretty slowly above 140.
#20
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Join Date: Aug 2002
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Ok...here's a pseudo-scientific top speed calculation:
Power = Force * Velocity
In this case, the force is due to drag which is also a function of velocity:
Drag = (1/2)*Density*Velocity^2*Cd*S
I'll use sea level density of 1.225 kg/m^3 (I prefer metric...) Also, assume that the Cd = 0.32 (which is probably being generous), and the projected area is 2.25 m^2 (from Honda's specs). This gives us:
Drag = (0.441 kg/m)*Velocity^2
or:
Power = (0.441 kg/m)*Velocity^3
Assume that you have 200 rwhp at top speed (also being generous), this translates to 149,140 W. That gives us a top speed of:
(149,140 W/0.441 kg/m)^(1/3) = 69.67 m/s = 155 mph.
A speedometer can easily be 10% off, so that could explain why some people see above 160. I've checked my speedo against radar guns though, and mine is within 1 mph at ~50 mph, but that is not necessarily typical.
This method is obviously not completely rigorous. There are other losses not accounted for, and the actual numbers used would change based on ambient conditions and engine speed. But, this is pretty close to what the maximum expected top speed would be.
Power = Force * Velocity
In this case, the force is due to drag which is also a function of velocity:
Drag = (1/2)*Density*Velocity^2*Cd*S
I'll use sea level density of 1.225 kg/m^3 (I prefer metric...) Also, assume that the Cd = 0.32 (which is probably being generous), and the projected area is 2.25 m^2 (from Honda's specs). This gives us:
Drag = (0.441 kg/m)*Velocity^2
or:
Power = (0.441 kg/m)*Velocity^3
Assume that you have 200 rwhp at top speed (also being generous), this translates to 149,140 W. That gives us a top speed of:
(149,140 W/0.441 kg/m)^(1/3) = 69.67 m/s = 155 mph.
A speedometer can easily be 10% off, so that could explain why some people see above 160. I've checked my speedo against radar guns though, and mine is within 1 mph at ~50 mph, but that is not necessarily typical.
This method is obviously not completely rigorous. There are other losses not accounted for, and the actual numbers used would change based on ambient conditions and engine speed. But, this is pretty close to what the maximum expected top speed would be.