any math formulas ?
- Thread starter USAJon
- Start date
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moper
Well-Known Member
Moroso slide rule is fairly accurate for ET prediction. There are similar powerwed calculators on line. As far as the HP question... There isnt one. WAY too many variables.
bOb shingler
Well-Known Member
wallace racing calculators
TheGreenSlime
Well-Known Member
I pulled this from one of my posts on FBBO. Some of it seems relevant to your request.
"As mentioned above, 12.50's AND decent mileage is not going to happen unless you spend cubic $$$$ or buy a computer controlled aerodynamic reissue muscle car - more cubic $$$$.
Here's breaking down your request mathematically:
12.50 ET should be around a 108 MPH trap speed http://members.tripod.com/fast_wheels/1-4speed.htm
Your car weighs (according some info on the web) 3700 lbs. Add you and gas that could end up near 4000 lbs. - so lets say 4000 lbs.
I rearranged the late the late Roger Huntington's formula - MPH = 224 (hp/weight)1/3 to get HP: HP = lbs (MPH/224) ^3. ^3 means cubed.
108 / 224 = .4821. .4821 ^3 = .112. .112 x 4000 = 448 HP. My guess that's applied rear wheel HP and that translates to a healthy engine. You will also need to have the suspension set up for 1/4 mile performance and that means low gears and higher cruise RPM's. None of which are gas mileage friendly.
For approximate fuel usage based on HP I think I can use some marine calculations for brake specific fuel consumption. I get .4-.45 lbs of fuel per hour per HP. Fuel weighs about 6 lbs / gal, so at peak HP (448) you will use 33.6 gals of fuel per hour. Naturally, part throttle freeway cruising will use much less fuel and I think I'll just let some mathematician come up with that answer".
"As mentioned above, 12.50's AND decent mileage is not going to happen unless you spend cubic $$$$ or buy a computer controlled aerodynamic reissue muscle car - more cubic $$$$.
Here's breaking down your request mathematically:
12.50 ET should be around a 108 MPH trap speed http://members.tripod.com/fast_wheels/1-4speed.htm
Your car weighs (according some info on the web) 3700 lbs. Add you and gas that could end up near 4000 lbs. - so lets say 4000 lbs.
I rearranged the late the late Roger Huntington's formula - MPH = 224 (hp/weight)1/3 to get HP: HP = lbs (MPH/224) ^3. ^3 means cubed.
108 / 224 = .4821. .4821 ^3 = .112. .112 x 4000 = 448 HP. My guess that's applied rear wheel HP and that translates to a healthy engine. You will also need to have the suspension set up for 1/4 mile performance and that means low gears and higher cruise RPM's. None of which are gas mileage friendly.
For approximate fuel usage based on HP I think I can use some marine calculations for brake specific fuel consumption. I get .4-.45 lbs of fuel per hour per HP. Fuel weighs about 6 lbs / gal, so at peak HP (448) you will use 33.6 gals of fuel per hour. Naturally, part throttle freeway cruising will use much less fuel and I think I'll just let some mathematician come up with that answer".
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