looking for a program that will give me eta and mph from horspower and wieght anyone now where i could get this info

 

ET = ³ root (weight/hp) x 5.825

mph = ³ root (hp/weight) x 234

-Mindgame

 

if you want a "free to Public & Race Community" computer program

http://www.maxracesoftware.com/race_car_physics.htm

its much more involved than ;

ET = ³ root (weight/hp) x 5.825

mph = ³ root (hp/weight) x 234

-Mindgame

but you can also tryout very many "what if" , find out best rear gear and trans ratios, tire sizes, shift points, etc.

 

Oh yes... much more complicated than that. You and I both know that Larry.

That's just a quickie empirical formula that's been around a long time.

http://www.maxracesoftware.com/race_car_physics.htm

Larry,
What variables are you including in your calculations? What about wheel mass and centroidal radius of gyration. How are you accounting for that with different wheel designs? I'm assuming that there's a good deal of empirical data in there. What about tire and clutch slippage?

Just curious.

-Mindgame

 

I am with you on wheel mass, but "centroidal radius of gyration"??? I am going to have to look that one up. But how can I minimize it in my setup? It sounds like something you want less of

Rich

 

Rich,
It's important in simulation because we need to know where the mass is concentrated in the wheel design. If you have a wheel that has a good deal of machining about the center, that wheel is going to have a larger radius of gyration as more of the mass is probably towards the outside of the wheel. A heavy-center wheel, like the old Cragar SS, would have a smaller radius. Can't calculate angular acceleration without it, so it becomes a necessary evil.

Now how that helps you I don't know, but the majority of the programs I write probably wouldn't mean much to anyone else either... as long as they work like you want them too.

-Mindgame

 

The "centroid" is the center of mass, and the "radius of gyration" is the point where the total mass of the wheel may be assumed to reside, for purposes of inertial calculations. The terms can also be used with reference to stress calculations, when cylindrical shapes are considered. In that case, "centroid" is referenced to the area of the stressed member.

 

Performance Trends has a new rotating inertia calculator program. It's not on their website yet, but it's being advertised. They are pretty good about not having vaporware.

Maybe Mindgame wrote it for them!

There's always the old empirical method of hanging your wheel/tire/hub/brake disk from the ceiling with 3 wires, rotating it, and timing the period of winding/unwinding. The math is easy, but I'd have to look it up.

 

Larry,
What variables are you including in your calculations? What about wheel mass and centroidal radius of gyration. How are you accounting for that with different wheel designs? I'm assuming that there's a good deal of empirical data in there. What about tire and clutch slippage?
Just curious.---Mindgame
================================================== ==

>>I'm assuming that there's a good deal of empirical data in there.<<

i tried very hard to eliminate all empirical algorithms out of ET_Analyst and just use good old Physics equations for better accuracy in modeling acceleration.

There's no ;
ET = ³ root (weight/hp) x 5.825
mph = ³ root (hp/weight) x 234 ,..... type of algorithms in ET_A

>>>What about wheel mass and centroidal radius of gyration. <<<

all that is being calculated and accounted for in ET_A ...give it a tryout
you can change Wheel or Rim Diameter and/or Width , and see effects of Inertia (Polar Moments of Inertia), same with Tires, Engine Size, etc

ET_A models 53 Input variables ...i never worked out the "Permutations" of 53 variables, but it must be astronomical

The included "Weather Model" in ET_A , also does a great job of "Predicting"
the weather condition's effects upon ET/MPH Times

Example=> NHRA ProStock Car (Greg Anderson) ...ET_A models Greg's ProStocker within thousandths of a second accuracy from near sea level to as much as 5860 Ft + elevation ..same with ProBike MotorCycles, etc.

Note=> use the published NHRA weather data's Barometric Pressure, Temp, and Humidity numbers...don't use NHRA's altitude data in ET_A , as for some reason NHRA's adjusted altitude data is not that accurate or accurate enough
as their other data

>>>What about tire and clutch slippage?<<<

All being calculated and modeled in ET_A

Tryout TopFuel Dragster and FunnyCars models in ET_A ,
and i'm pretty confident that ET_A is the only program out there that
will correctly model TopFuel Dragster/FunnyCar 's 1/8 mile MPH times !
All others do a good job with 1/4 mile MPH , but are off in 1/8 mile in T/F & F/C Classes
The "Clutch Slip Algorithm" for T/F and F/C , seems to work pretty good.
...same with other type Classes.

ET_A also has a Lift Coefficient input to help model the effects of Wing DownForce especially critical in T/F & F/C Classes, again at or near the 660 Ft mark till 1320 Ft. The combinations of Tire Growth Model, Clutch-Slip Model, Wing DownForce Model, etc. all help in especially in T/F & F/C

<<< tire slippage ? <<<

Tire Slippage is being controlled or limited by the Tire Friction Coefficient
(Tire Traction Coefficient).... with the ET_A DOS-version, i'm about at the limit for a DOS program in what i can do with calculation speed and size, so the Tire Friction Coefficient was a good way to keep calculation speed up, and ET/MPH Times still have very good accuracy .

 

NHRA's weather data=
7:52 PM 29.62 Absolute Barometer, 72 deg F, 92 % Rh, adjusted altitude = 1659 Ft

if you use
http://www.weatherunderground.com/hi...lyHistory.html

data average between 7:50 and 8:10 PM
then its
29.92 Corrected Sea Level Barometric Pressure
81.5 degrees F average from 7:50 to 8:10 PM
81.5 Relative Humidity PerCent average

leave all data the same as when ET_A 1st starts up but just change the weather data to above and you get these numbers with using NHRA's 540 Ft Physical Elevation height for Millington, TN (Memphis)
Dist Time Speed
Feet ET MPH
12.0in -.146 9.253
60 = 1.004 67.982
330 = 2.830 128.718
660 = 4.359 160.932
1000 = 5.676 187.471
1320 = 6.788 202.742

MILLINGTON, Tenn. - SUMMIT FastNews - Order after 2 rounds of qualifying in Pro Stock at the NHRA POWERade Drag Racing Series, 17th annual O'Reilly Mid-South Nationals presented by Pennzoil:
Psn Driver Vehicle ET Speed
1. Dave Connolly Bullet Motorsports Cavalier 6.790 202.58
2. Greg Anderson Summit Racing Equipment Grand 6.816 201.49

i don't know how good Track was hooking in 60 Ft
so the Tire Friction Coefficient might have been less than 3.008

if Tire Traction Coefficient was 2.897 then you get pretty good ET/MPH Correlation
Dist Time Speed
Feet ET MPH
12.0in -.148 9.035
60 = 1.017 67.421
330 = 2.853 128.390
660 = 4.385 160.745
1000 = 5.704 187.353
1320 = 6.816 202.634

NHRA's weather data
4:59 p.m. Weather conditions: air temperature 78 degrees, relative humidity 92 percent, barometer 29.60 Absolute UnCorrected inches, adjusted altitude 2,113 feet, track temperature 107 degrees

Weatherunderground's weather data
4:50 to 5:10 PM
29.90 Corrected Sea Level Barometer
88.7 deg F average
64.0 % Relative Humidity
with using NHRA's 540 Ft Physical Elevation height

Dist Time Speed
Feet ET MPH
12.0in -.146 9.253
60 = 1.006 67.837
330 = 2.836 128.397
660 = 4.369 160.556
1000 = 5.690 187.034
1320 = 6.804 202.266


This is the most off or difference i've seen between the National Weather Service and
WeatherUnderGround -VS- NHRA's reported weather data

a quick easy Corrected Sea Level Barometer to Station Pressure or UnCorrected Barometer is=>

StationPressure = ((760 - (.026 * DragStrip_Ft)) / 760 ) * Corrected_Barometer

Example=> 29.367 StationPressure = ((760 - (.026 * 540)) / 760) * 29.92

NHRA shows Station Pressure as 29.62
and the National Weather Service shows Station Pressure approx at = 29.367

NHRA shows Temp at 72 deg F ( NWS shows = 81.5 F )
NHRA shows Rh% at 92 % (NWS shows = 81.5 F )

a lot of difference between NHRA and the National Weather Service ???

 

i cant get the dos version to work on my pc...why isnt there a DL for the Windows version??

 

were you able to "UnZip" the Zipped file ?? ETAVBDOS.ZIP ??

or i you like just download the .EXE..this file needs no UnZipping
http://www.maxracesoftware.com/ETAVBDOS.EXE

if ETAVBDOS.EXE still will not run on your Computer ..i'm at a loss, you'll be the very 1st person ...if you see the License Agreement screen, its actually running...if you can't go past that screen its because your Mouse isn't working in DOS.....then you probably have Window's 2000 OS Home or Standard Edition and you have to press these 2 Keys together at the same time ALT + ENTER that switches you to DOS screen where Mouse will work
press ALT + ENTER keys once more to switch back to Windows screen

http://www.maxracesoftware.com/Read_Me.txt

read the Read_Me.txt file

 

a quick easy Corrected Sea Level Barometer to Station Pressure or UnCorrected Barometer is=>

StationPressure = ((760 - (.026 * DragStrip_Ft)) / 760 ) * Corrected_Barometer
================================================== =====

a slightly better "Fit" than the above Formula all the way to 6000 Feet is

StationPressure = ((760 - (.0241 * DragStrip_Ft)) / 760 ) * Corrected_Barometer

the "Corrected Barometer" is what is reported on the Cable TV Weather Channel

NHRA usually is reporting "Station Barometer" (unCorrected Barometer)

...or the reverse Formula=>
Corrected_Barometer = (Station_Pressure * 760) / (760 - (Elev_Ft * .0241))

.0241 is slightly better "Fit" Constant to use than .026

 

You running Windows XP Lightning-Killer?

Getting a subsystem error (autoexec.NT) when you try to run the program?

First try changing the compatibility of Winblows' (whoops did I say that) pseudo-emulator to "Windows 95" and check the 256 colors and 640x480 resolution boxes.

Ok, to get that far you need to right click the ETAVBDOS.EXE, go to "Properties" then "Compatibility".

Try that and see if it works. I'm doubting it will but ya never know til you try.

-Mindgame

 

i cant get the dos version to work on my pc...why isnt there a DL for the Windows version??---Lightning-Killer



Lightning-Killer... i just uploaded a free Windows version at this Link


http://www.maxracesoftware.com/windows__version.htm