I always did hate math.....But this takes it to a whole new level 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.

 

an average of 646 hp to the ground + the power to overcome air resistance which I should be able to factor in tomorrow

 

I have COMP's truck at 598 HP + air resistance

 

average of 405+

 

The SRT-10 has a Cd = 0.45 and a frontal area = 34.6 square feet. A regular 4x4 2500 3rd gen Ram has a Cd figure of 0.50 and roughly the same frontal area. 2nd gen 1500 Ram's have a Cd=0.44 and frontal area = 34.5.

brandon. (not a rocket scientist)

 

cool, thanks!!!

 

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~

 

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.

 

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~

 

I am still unsure of the accuracy of the Aerodynamic portion.....still looking for a Rocket Scientist

 

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)

 

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.

 

All this number crunching has got my head a spinnin....

Good thread !

 

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