Math for fun and racing!
12-14-2005, 12:35 AM
#32
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Originally Posted by cumminsdriver635
I always did hate math.....But this takes it to a whole new level 
How many HP should my truck have at 6500lbs?
Eric
How many HP should my truck have at 6500lbs? Eric
not counting air resistance, the truck averaged 217 HP for the entire run.
After I talk with my local Rocket Scientist I will have the rest of the story including the power required to overcome the air resistance for the run. (this requires a little integration which I will spare you all from seeing)
EDIT: Manual tranny guys will hate this....average hp will be significantly lower than peak HP......due to the fact that you are slowing down each time you shift.
12-14-2005, 12:59 AM
#33
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Originally Posted by Rods
Hey Don do Chris Hoofnagle's truck , ill say with his #s 11.76 @113.4 mph
and weight would b 7200 ??? 800+
and weight would b 7200 ??? 800+
12-14-2005, 01:16 AM
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Originally Posted by Gene007
Don, I tried with a regular calculator, using the directions you gave in your example. I'm missing something because I cannot get the cube root of 6. I tried running my trucks numbers 13.95 sec, 103 mph, weight is 7000 lbs. I'm comming up with any where from 500 to 600 hp. I'm baffled 
Of course I have trouble getting my fuel mileage right. 
Regards,
Gene
Of course I have trouble getting my fuel mileage right. Regards,
Gene
average of 405+
12-14-2005, 01:57 AM
#36
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Originally Posted by Diesel Freak
If anyone has the Aerodynamic drag coefficient of a dodge 2nd gen truck, then we can get down to the gnatts butt!!!
brandon. (not a rocket scientist)
12-14-2005, 11:57 AM
#38
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Patricks calcs include a pile of variables. In the end the constant of 5.825 was just about perfect for NA gassers. We tweaked the 5.425 for our engines. It is eerily close to right. I typically calculate within 1.5% of actual on the Dynojet.
He uses:
Elevation
Temperature
Baro
Humidity
Transmission gear ratios ( all of them, be it an auto or manual )
Weight
Rollout
Wheelbase
Frontal area
Body style ( dragster, altered, funny car, etc, etc )
Clutch type ( converter or manual )
Slip/Stall speed
Final drive ratio
Tire diameter
Tire width ( very important !!!!! )
Shift RPM
Peak HP ( if you have it from a dyno )
RPM @ peak HP
Displacement
Millions of entries for the gassers have boiled it all down to the constant of 234 and 5.825
We took it further for the TDiesel and came up with 250 and 5.425.
Please include 4 wheel drive and consider tire type for our trucks in the mix. It is a make or break part of the calculation. 4WD trucks flat out hook the heck up. Acceleration is changed huge.
Don~
He uses:
Elevation
Temperature
Baro
Humidity
Transmission gear ratios ( all of them, be it an auto or manual )
Weight
Rollout
Wheelbase
Frontal area
Body style ( dragster, altered, funny car, etc, etc )
Clutch type ( converter or manual )
Slip/Stall speed
Final drive ratio
Tire diameter
Tire width ( very important !!!!! )
Shift RPM
Peak HP ( if you have it from a dyno )
RPM @ peak HP
Displacement
Millions of entries for the gassers have boiled it all down to the constant of 234 and 5.825
We took it further for the TDiesel and came up with 250 and 5.425.
Please include 4 wheel drive and consider tire type for our trucks in the mix. It is a make or break part of the calculation. 4WD trucks flat out hook the heck up. Acceleration is changed huge.
Don~
12-14-2005, 02:16 PM
#39
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here is the aerodynamic component I came up with for a 2nd gen truck
HP = (.001773(Trap speed)^3))/ET
and for a 3rd gen truck
HP = (.002021(Trap speed)^3))/ET
I need to consult with our resident rocket scientist to make sure these are correct, but I believe they are close.
HP = (.001773(Trap speed)^3))/ET
and for a 3rd gen truck
HP = (.002021(Trap speed)^3))/ET
I need to consult with our resident rocket scientist to make sure these are correct, but I believe they are close.
12-14-2005, 09:02 PM
#40
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COMP461 swears the Edge Wolverine weighs a hefty 3800 pounds. According to his posts anyway. He may not be too far off the mark. The truck in Tenn is reported on their website to be 3550. Its a ranger, not a full size RAM like the Edge rig.
Care to calculate some numbers to see how much power they will need to bury COMP?
To run a 8.20 I had them needing over 1100 at the rear wheels. Lets hope COMP is incorrect on the weight. Otherwise, big power will need to be made to deal with the PHATNESS
Don~
Care to calculate some numbers to see how much power they will need to bury COMP?
To run a 8.20 I had them needing over 1100 at the rear wheels. Lets hope COMP is incorrect on the weight. Otherwise, big power will need to be made to deal with the PHATNESS
Don~
12-15-2005, 06:46 PM
#42
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woo hoo!!!!
finally got it....
this is the complete aerodynamicly corrected 2nd gen 1/4 mile HP calculator
Average Horsepower for a 1/4 mile run= (0.1095 x Vehicle Weight x Trap speed) / ET˛ + 75236/(ETł)
finally got it....
this is the complete aerodynamicly corrected 2nd gen 1/4 mile HP calculator
Average Horsepower for a 1/4 mile run= (0.1095 x Vehicle Weight x Trap speed) / ET˛ + 75236/(ETł)
01-03-2006, 10:57 PM
#43
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Originally Posted by Don M
Remember his engine is P pumped and uses enough Nitrous to fill a hot air ballon. LMAO
Don~
Don~
The 8.72 run was done with just water. (so he says?) He ran a 8.5X using nitrous, but that was a close course testing day with no crowd.
08-05-2007, 02:39 PM
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Interesting old thread.... 
The only thing I can think of is that Texas must have had a massive snow storm during this time period. At least a 1/2 inch or so of snow on the ground would likely be enough for them Texans. Was Don stuck at home snow bound?
--Or--
Maybe a grand child just wanted to know "Whats this thing for Grandpa?". The Ti-99 is pretty old and you can't make calls on it. Maybe just quick lesson and then some..... ?
Jim
The only thing I can think of is that Texas must have had a massive snow storm during this time period. At least a 1/2 inch or so of snow on the ground would likely be enough for them Texans. Was Don stuck at home snow bound?
--Or--
Maybe a grand child just wanted to know "Whats this thing for Grandpa?". The Ti-99 is pretty old and you can't make calls on it. Maybe just quick lesson and then some..... ?
Jim