06-19-2024, 09:40 PM | #31 | |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,109
|
Quote:
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124 |
|
|
06-19-2024, 09:43 PM | #32 | |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,109
|
Quote:
Imagine being this confident, and still wrong. Baffling
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124 Last edited by Megadan; 06-20-2024 at 01:59 AM. |
|
|
06-19-2024, 09:44 PM | #33 |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,109
|
Congrats on being the only correct person here, besides me
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124 |
|
06-19-2024, 10:49 PM | #34 | |
Join Date: May 2013
Location: finger lakes NY
Posts: 2,061
|
Quote:
Also, guess not everyone knows that HP is just TQxRPM/5252 To get the arbitrary number everyone drools about... |
|
|
06-19-2024, 11:44 PM | #35 | |
Join Date: Feb 2021
Location: Kansas City
Posts: 2,682
|
Quote:
OK. The thing is, he will have lower gearing available for more torque if he does. I'm thinkin he will. Well, it's how I explained it anyway... same speed at higher rpm. More torque!
__________________
No matter where you go, there you are |
|
|
06-20-2024, 01:59 AM | #36 | |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,109
|
Quote:
Actually, maybe I can help them with it. Just for fun, lets say our engine makes 10ft-lb's of torque at 4000rpm in 4th gear. Let's say the primary gear reduction is 4:1 and we are in 4th gear, which is 1:1 for some simplicity. Total Gear Reduction: 4 x 1 = 4 or 4:1 at the counter shaft - where the front sprocket is located. Since Gear ratios multiply torque by dividing RPM, the Countershaft now has 40ft-lbs of torque and the counter shaft is spinning 1000RPM We can plug in the engine figures to get hp with the equation: 10ft-lbs x 4000rpm/5252 = 40,000/5252 = 7.61hp What about the counter shaft, let's do that math, shall we? 40 x 1000/5252 = 40,000/5252 = 7.61hp So, having gone through ONE gear reduction the HP is the same at the crank and the front sprocket. Let's go to the rear wheel, shall we? Then, let's say we have a 17 front 46 rear to start with, or 2.71:1 40ft-lbs x 2.71 = 108.4ft-lbs. 1000rpm/2.71 = 369rpm So our stock gearing is producting 108ft-lbs at 369rpm at the rear wheel. (go ahead and do the math for MPH if you want). Next, let's say we have a 15 front and 46 rear, or 3.07:1 40ft-lbs x 3.07 = 122.8ft-lbs 1000rpm/3.07 = 325.73rpm at the rear wheel. So far, the new sprocket has increased torque at the wheel, but reduced maximum wheel RPM at the same engine RPM point - exactly as Thumper, myself, and bogfie boy said. Not looking too good for you keyboard warriors/experts. But, let's keep going and see if it does indeed increase horsepower at the rear wheel. To reiterate, HP = Torque x RPM / 5252 Let's do some math! Stock gearing, at the rear wheel we had 108ft-lbs at 369rpm HP = 108.4 x 369/5252 HP = 39999/5252 HP = 7.61hp Huh.. Look at that HP figure... Smaller 15t front sprocket gearing we had 122.8hp and 325.73wheel rpm HP = 122.8 x 325.73/5252 HP = 39999/5252 HP = 7.61hp Gosh... look at that. The HP is unchanged, just like we said. So, gents, the math has spoken. If you argue past this point you are simply trying to sooth your hurt ego. Truth is, I don't care. We are right, you are wrong. The end. P.S. If you want to try and argue driveline loss, it's irrelevant in this example as the loss is a fixed value that would apply to all of the figures. It would also be counter point to your argument since it is... a loss.
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124 Last edited by Megadan; 06-20-2024 at 02:30 AM. |
|
|
06-20-2024, 09:56 PM | #37 |
Join Date: Aug 2013
Location: FL
Posts: 357
|
@megadan, you're still wrong tho.
You base all the torque figures off of a dyno with one specific load. A small dyno may be showing correct numbers for a certain vehicle (like an economy car, or a bike), but put a truck or a real sports car on it, and the numbers will be off from their actual values. Put an economy car on a truck dyno, where the rollers are much heavier, and the well tuned dyno will show that the economy car has higher HP and tq values than on the smaller dyno. This, because the heavier rollers simulate much greater road resistance, like that of a truck, or that of a sports car driving real fast. You think an engine has a fixed amount of torque or HP, but that's not true at all. Increasing the load on an engine, is likened to advancing the timing. Your engine will run more efficiently with a timing advance, or a higher load, until either the load or the timing advances becomes too much. Then it'll bog down and die, and torque and HP output will be zero. The math you're using assumes nothing of engine load. It's just a formula you'd use if you assumed the load on the engine is exactly the same in all gears. It is used often as a simplification to explain how HP and tq work, but it's flawed, and much more complex in real life than the formula indicates. Added to an increase in efficiency, there are also added losses, like friction, heat, and other losses that counterbalance the increase in efficiency. But generally speaking, especially with air-cooled engines, they run inefficient. And gearing higher, or advancing the timing are 2 methods to harvest more energy out of the engine, running the same speed for less fuel. |
|
06-20-2024, 10:05 PM | #38 |
Join Date: Feb 2021
Location: Kansas City
Posts: 2,682
|
Hah! Funny!
Is this a race? No... a descension into hilarity. It really is simple. Engines have a peak hp recognizable on their power output curves. If you can run at rpm that generates more hp, great! Lower gearing can help you optimize this since gearing down an engine provides more torque closer to the peak output/rpm. Of course, the driver needs to know how to use it. That is the only question we can't really answer!
__________________
No matter where you go, there you are |
|
06-20-2024, 11:21 PM | #39 | |
Join Date: May 2013
Location: finger lakes NY
Posts: 2,061
|
Quote:
Youre just spouting BS at this point to tey and prove your point... We could just agree with you, but then we would all be wrong.... |
|
|
06-21-2024, 12:39 AM | #40 | |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,109
|
If I am wrong, PROVE me wrong. Provide reputable sources to back your claim, or do the math yourself and post it here (like I did) to prove me wrong.
Otherwise, stop talking. You're not only wrong, you're just ignorant and arrogant. The math I am doing doesn't care about engine load. Put in our own torque figure for a different load. Go half the torque, or a tenth of the torque I listed at any given RPM point. Pick a number, ANY number, and it will give you the calculated HP figure for that amount of torque at that given RPM point. Then do all the same math I did for all of the same gear ratios. The horsepower number won't change because of any gearing/sprocket changes. The ONLY reason the HP figure will change is because the torque value changes, which is kind of a "Duh" thing when you are changing the load. Want quick proof? Instead of 10ft-lbs at 4000rpm, let's say we only need 5ft-lbs at 4000rpm. Let's run through the stock gearing examples above. At the counter shaft, stock gear, 5ft-lbs of "load." HP = (5x4) x 4000/4)/5252 HP = 20ft-lbs x 1000rpm/5252 HP = 20000/5252 HP = 3.8hp At the rear wheel. HP = (20x2.71) x (1000/2.71)/5252 HP = 54.2 x 369/5252 HP = 19999.8/5252 HP = 3.8hp Different load, same result... Man, it's almost like myself and a couple other people here already explained all this or something The argument was that sprockets change HP at the rear wheel, nothing else, and I proved that wrong with the math above. Period. Evidence of your post making that claim: Quote:
https://chinariders.net/showpost.php...8&postcount=12 I also attaching a screen shot of that post to this reply, just in case somebody wants to get cute and try to edit things. No, I don't play around. It's linked, click to make it bigger. The ball is in your court, do it right or stop running off at the mouth. I just proved you wrong, end of story. P.S. Your engine load theory is manure. Any difference you MIGHT see at the rear wheel would come down to margin of error or miscalibration. If you don't think one of these bikes is under enough load in 4th or 5th gear to put out max rated power (derived from a brake dyno, aka, loaded) you need to re-evaluate things. Heck, they can be loaded enough in third gear. If your whole theory is based on a stock Hawk topping out at 59mph, and with a 17/45 capable of 68mph. That's down to where the engine peak power is in the RPM range, not the load on the engine. Peak Torque at 5000-5500, Peak HP at around 6500-7000. Do the math on the gearing and you will see what speeds you achieve at the power peak for each sprocket combination. gearingcommander.com
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124 Last edited by Megadan; 06-21-2024 at 04:06 AM. |
|
|
06-21-2024, 06:29 AM | #41 |
Join Date: May 2013
Location: finger lakes NY
Posts: 2,061
|
@megadan, i think the biggest problem is this guy still thinks HP actually means anything.... when its a completely arbitrary number, the torque value for the stated rpm is what means anything at all, which as numerous people have already gone over, changes with gearing changes yet that mythical number called hp always stays the same no matter what the gearing changes do...LOL however applied torque certainly will change with gearing changes... thats how ratios work LOL but this guy cant seem to wrap his brain around that FACT....
|
|
06-21-2024, 07:43 AM | #42 | |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,109
|
Quote:
You know.. energy, like electricity, given in watts or something. Maybe that's why you can convert Horsepower to Kilowatts... hrmmm.... Oh, wait, we're dumb and don't know anything. Oops!
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124 |
|
|
06-21-2024, 09:24 AM | #43 |
Join Date: Aug 2013
Location: FL
Posts: 357
|
Sorry, I've tried to explain to you. You just look at static dyno figures that aren't real world figures. All your math takes into consideration is one readout of one dyno result, that's stickered on an engine.
Surprise, you can actually get higher HP values out of your engine than whatever is stickered on it by the factory. Anyway, you're hard headed and don't understand what I'm talking about, and I'm not going to spend any more time trying to explain the errors in your math. Doesn't mean you're right, just means if you refuse to see where you're wrong, there's nothing else I can do. |
|
06-21-2024, 09:32 AM | #44 | |
Join Date: Aug 2013
Location: FL
Posts: 357
|
Quote:
I understand what you're saying, in fact I even see the flaws in that theory. Just read my previous response. HP values are determined by the factory which did tests on a fixed load. Change the load on an engine improves efficiency, thus if we assume that the factory rating is correct, a higher gearing will in fact cause higher horsepower. There's a difference between the rated HP values, and the actual HP values. How else will you explain higher efficiency? How can an engine run at a higher efficiency, and not produce more HP? That doesn't make any sense at all. And the proof is in the pudding. Change the gearing, get higher performance, until you reach peak performance. After that (too tall gears) and the engine won't have enough power anymore, and will produce less HP than rated. But if you really can't wrap your head around this, Then think of it like this: An engine rated at 11 HP, from the factory only makes 10hp. By changing the gears, you can make it do it's rated 11hp, transferring more HP to the wheels than stock, reaching it's rated HP values (what stock never could do). |
|
|
06-21-2024, 01:56 PM | #45 | |
Join Date: May 2013
Location: finger lakes NY
Posts: 2,061
|
Quote:
Im done arguing with this |
|
|
|
|
|
|