9/11/2023 0 Comments Turbo calculator hpWe wish, but the engine is only making 300 HP. If you burn 24 gallons of fuel per hour to make 300 HP, 142lbs/1 hour, you release 2,699,520 BTU’s of energy, (19,000x 142). So 24 gallons x 5.92 lbs = 142 pounds per hour to make 300 HP. 1 Gallon of fuel weighs approx 5.92 lbs and for every 1 lb of fuel burned approx 19,000 BTU’s of energy is released. It may use approx 24 gallon per hour to make 300 HP. For reasons of simplicity let’s take an engine that makes 300 HP. 1 BTU is heat energy required to raise the temperature of 1 pound of water 1° F which is equal to 778 Foot – pounds of energy.ġ Horse power (33,000 Ft-lbs per minute) is the same as 42.4 BTU’s per minute or 2545 BTU’s per hour (33,000 /778 = 42.4165 x 60=2544.98).įor any engine you can calculate the amount of fuel used, its thermal efficiency and its horsepower potential. So, here are a few things to consider when hearing about all of these high powered internet engines.Įngines turns chemical energy (fuel) into heat energy (combustion) and some of that heat energy is turned into mechanical energy or work (torque). I thought if I put some basic proven and accepted calculations in a paper they can be used to obtain and understand what is real and what is not. The internet has created bragging rights for engines with huge horsepower figures, which never live up to the stated performance and seem to defy the laws of physics. Same can be said about cars that have real engines with real horsepower. There is a saying that money talks and BS walks. Porsche 944 and 968 Crankshaft Upgrades.Porsche 911 Type Air-Cooled Cylinder Head Rebuilding.Porsche 944-968 Engine Block Lower Member Upgrade.Replacement CDI Ignition for Porsche 911 Carrera and Turbo Engines.996 and 997 Turbo Crankshafts and Rod Bearings.Porsche 996 and 997 Turbo Cylinder Head Sealing.For example, if you ran that 12.0 at 3750 lbs and want to know how much taking 100 lbs off the car would help, calculate hp at full weight to get 427.5 hp, and then use that and the lighter weight to calcuate the new et, 11.89. Do the math yourself, and even if the number is a little wrong it will be consistent so you can evaluate changes. That's what the online calculators do that start with mph, they just don't show the equations and don't tell you what they are using for the fudge factor (I've seen anywhere from 1340 to 1370 ). The mph is much more reproducible at the track than the et, so what I like to do is use the mph to calculate the et then use that in the hp formula. F bodies usually mph 2-3 higher for the same et so that number should be changed for them, etc. For G bodies I fit the 180 reader's rides times at and got 1356, so I use et = 1356 / mph, so a 12.0 would be at 113.0 mph. The formula is et = constant / mph, and if you ignore aerodynamics then physics says the constant is something like 1450 (that's a real fuzzy memory and a number NOONE uses ). Relating et and mph with any accuracy at all requires a fudge factor to account for aerodynamics, and here you will get different numbers from different online calculators. So if your car weighs 3600 and you weigh 150 lbs so the total is 3750 lbs and you ran a 12.0 you averaged 427.5 whp applied to the track. This equation is exact and includes no fudge factors of any kind, just unit conversions. ET's are hard to reproduce but ignoring that you can derive (I posted this 6-8 years ago if you want to see all the equations) that the average whp = 197 * weight in pounds going down the track / (et * et * et). This gives a minimum average hp estimate, which to me is a good thing - you might make more hp some of the time but if so, you must be making less hp some of the rest of the time. You have to make some kind of assumption about the variation in hp to get an answer from physics, and the simplest one to make is to assume that hp is constant for the entire pass. All of that is why I derived them myself a long time ago. Most of the online calculators that I've looked at estimate wheel hp applied to the track, although almost none of them say one way or the other and most people have no idea, and many will argue that it must be flywheel.
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