Racing Physics: Class #4. Why Horsepower, not Torque, ultimately matters most.
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- Опубліковано 25 жов 2024
- In this lesson, I describe why horsepower is ultimately used to measure race engine performance instead of torque. Here I bring back the same V-Rod vs. big bore Twin Cam as an example of two extremes of the types of engines that are out there: Big inch monster torque engines with high horsepower at relatively low RPM and smaller lower torque engines making high horsepower at very high RPMs.
More air in = more good out. Both low end torque and high end horsepower. I haven't raced in forever but always love tinkering with whatever I have and discovered that no matter what, more air makes a better running engine and more smiles per gallon.
I believe what you are saying. If you look at many racing disciplines, they have been turning higher & higher RPM until they have reached a ceiling of costs/reliability, then guy's just started making larger displacement engines. But, getting an engine to make power at 10K + RPM takes a lot, first and foremost, a cylinder head that can flow the required air. The cylinder head & induction package is the single biggest limiting factor in turning higher RPM. If the head chokes @7500 RPM, a bigger cam won't help etc. Great info.Thank you.
Thank you. So far these videos I’ve made have been just a warm up to deeper understanding of the engine. I’m not breaking new ground by any means. Just sharing what I’ve learned.
Torque to accelerate, hp to maintain or recover rpm. Racing of all forms proves that to be true.
Why 18 wheelers us massive Torque, circle track depends on HP, and tractor pulls need both.
A big block with same HP will win over a equal small block.
One thing that people fail to consider when making the comparison between these two types of engines is, the higher rpm less torque engine will get a lower gear ratio to get the revs up there and at the same time the lower gear ratio multiplies the torque more than the higher ratio. That is also the reason for possible same ET's. It's not rocket science.
It's more like "sprocket science"!
im with you mate.. i also noticed you explained gearing and ratios quite well and never mentioned horse power, only torque and rpm...lol.
@@gfarnden56 Just to be clear I only mentioned torque and RPM because the 2 engines compared in video were close to same HP. I'm kinda in the happy middle ground as I find engines have a tendency to eventually get chewed up with to much RPM, but the engines with too much stroke create a lot of friction, not to mention needing heavy metal to balance more likely. I do tons of machine work for racers and I've seen it all. I just have a 600 hp engine in my car and it keeps on running and I have lots of fun. I will say it's great watching the really fast cars tho.
What type of car do u have?...
I have a 900whp wrx... its great fun.
I would argue that we cant make horsepower and that torque is the only thing that matters because its the only thing we can make.
horse power is only a calculated value based on how much torque you produce and how long it takes to produce said torque.
in order to calculate more horse power we need to produce more torque or take less time to produce the same torque.
if you increase air flow by changing heads or cams or forced whatever.... you will make more torque and also calculate a higher HP number.
Same if you shorten the time it takes...ie more rpm you will also calculate more HP.
torque is the twisting force that makes the wheels turn, no torque..no turn..lol.
ultimately you want as much torque as you can make without breaking stuff and produce it as quickly as you can this will calculate the highest HP numbers... sooo the highest rpm at the highest torque is the fastest because it does the most work... no need to calculate horse power..lol
Exactly. I covered just that idea in my Racing Physics Class #2 video.
Sweet as mate.. I'll give it a watch when I get home.
Cheers.
yea this formula is very close to real value for bike times fix very well speed turn out lil to high for me cb 500 it show 13,4 sec /102 mph me real world messurement 13,4 /97 mph in both dorection on flat tarmac no wind so very close for sv it show 12,3 / 111 mph vs real world data 12,3 /107 mph again time perfect vs speed lil exagerrsted but its for bike where cofsctor must be on 2,22 level +/- but it would depend on drag to weight to power level to gearing and peak width unless somebody know precise avg power in regard to oesk width and doffrences between gear lenght but in some cases from peak measured on dyno 100 hp can be avg use 70 hp cos peak be very thin feg and diffrences very big in somebascially all 100 hp can be use for accelerstion avg through whole distsnce at whell 👌🏻 so yea in some cases such cslculator can be waaay offf and in some very precise close to real test data 👌🏻🍿
Its not the brightest idea to use More RPM ......more friction.
you sure mate?
im thinking you are gonna have a hard time explaining that to the f1 car and bike engineers. Also top fuel and almost any other high power engine all rev to the moon
@gfarnden56 F1 and Top Fuel ?
In the real World....forget about high rpm for making HP.
Please remember....when Alonso won the F1 championship....his Renault engine went to 18,000 rpm.......2000 rpm less than The Schumacher Engine.....
Less RPM....less Friction.....less HEAT........
LESS RPM is cheaper,better and faster.
Torque is the ability to do work.
Power is WORK done in a given time.
Power doesn't exist....it's a CALCULATION
Using More RPM to make HP......is actually a mistake... .
Never saw YOU at the Seminar....'hiw to make HP'....
You are right. More RPM does mean more friction. But more RPM also can use higher intake velocities with proper intake, heads, and so on to ram more air into an engine increasing volumetric efficiency well beyond 100%. It’s a matter of diminishing returns as to when friction finally wins out. I’ll cover those concepts in future videos.
@@rageracing6435 more rpm....costs more money....pointless.
I respectfully disagree, but if you found a combination that gets you down the race track that you are happy with then keep doing what works for you. That’s the cool thing about motor sports is the variety of ideas put into practice.