View Poll Results: Who won the debate: MK (HP) or VR (Torque)
Mk won with a simple to understand concept that HP determines torque at the wheels at any speed.
25
17.48%
MK won: When comparing equal HP cars, the one with less torque COULD be better on the road course.
6
4.20%
VR won: When comparing equal HP cars, the one with more torque is better on a road course.
44
30.77%
Neither, as physics dont apply to race cars
18
12.59%
I don't want to open this can of worms again!
50
34.97%
Voters: 143. You may not vote on this poll
Poll: Who won the HP vs Torque debate?
03-19-2009, 02:27 PM
#316
Rennlist Member
There really are lots of factors here that are interacting which makes it less simple than which is better hp or tq .
03-19-2009, 02:31 PM
#317
Rennlist Member
the one example that makes the point and answers the question is the one that shows two equal HP engines , one with more torque than the other. the reason that the lower torque engine has more or equal torque at the rear wheels is due to its HP curve shape, thats it. can you refute this, at any speed on any track anywhere??
mk
mk
Show me the graphs again, you have created too many for me to figure out which ones you are referencing.
03-19-2009, 02:33 PM
#318
Ironman 140.6
Rennlist Member
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Bob, I think we are keeping this civil now and mildly entertaining.
I know what VR is getting at and I think you do too. However I think there might be a little confustion on his or others that voted the other way in knowing that you CAN have more rear wheel torque with less engine torque , on an engine that has the same peak HP, as started with the question from Dez.
It only has to do with the shape of the HP curve. It alone, determines the rear wheel torque. sure, we all want more torque, force at the tires when we come off a turn. that is determined by engine HP, not nessarily, an engine torque value. thats the only point of all this. Power has been set . with the curve shape being the only variable besides the numerical engine torque, can rear wheel forces be higher or lower for either?? absolutely.
so, yes, you get it from your weed wacker analogy. and it can provide equal torque at a speed coming off a turn, in theory and in reality. More often, VR's instincts are correct. Big torque engines genearlly have more grunt off the turns at the lower rpms, BUT NOT Always, and that has always been the argument here.
Thanks
Mk
I know what VR is getting at and I think you do too. However I think there might be a little confustion on his or others that voted the other way in knowing that you CAN have more rear wheel torque with less engine torque , on an engine that has the same peak HP, as started with the question from Dez.
It only has to do with the shape of the HP curve. It alone, determines the rear wheel torque. sure, we all want more torque, force at the tires when we come off a turn. that is determined by engine HP, not nessarily, an engine torque value. thats the only point of all this. Power has been set . with the curve shape being the only variable besides the numerical engine torque, can rear wheel forces be higher or lower for either?? absolutely.
so, yes, you get it from your weed wacker analogy. and it can provide equal torque at a speed coming off a turn, in theory and in reality. More often, VR's instincts are correct. Big torque engines genearlly have more grunt off the turns at the lower rpms, BUT NOT Always, and that has always been the argument here.
Thanks
Mk
Like Bob, I've got no skin in this game. Give it a rest (you are being openly mocked in this thread). Walk away from the keyboard grab a beer and relax.
03-19-2009, 02:33 PM
#319
Administrator - "Tyson"
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I have now read all 318 posts and I would like to change my vote.
03-19-2009, 02:36 PM
#320
Rennlist Member
Thread Starter
The extra cylider analogy is a little tough to conceptualize, at least for me, but I understand Magnus' point. The torque output of an engine has a torque ripple, and this get smoothed out the more cylinders you have firing, along with their timing. I think the assumption Magnus has made is that when you add more cylinders, you also reduce their torque and increase rpm proportionally so that there is equal mass flow, equal power, at the same vehicle speed.
Better and a little easier to just try and answer this question I asked earlier below:
"Here is a direct question for you. Do you not agree that two equal hp engines , one with lower vs higher engine torque, can produce equal rear wheel torque at ANY vehicle speed based on the same shaped HP curve?
Did you see the two curves I posted that showed exactly this?"
Thanks,
Mk
Better and a little easier to just try and answer this question I asked earlier below:
"Here is a direct question for you. Do you not agree that two equal hp engines , one with lower vs higher engine torque, can produce equal rear wheel torque at ANY vehicle speed based on the same shaped HP curve?
Did you see the two curves I posted that showed exactly this?"
Thanks,
Mk
03-19-2009, 02:42 PM
#321
Rennlist Member
Thread Starter
Here are the two graphs of two equal Hp cars, one with 60ft-lbs less engine torque, yet both are near the same HP peak.
the last graph is the criteria of the entire discussion. two engines with different torque peaks, yet equal HP. the peak torue and Hp points were also determined by Des . the only interpretation can be the shape of the curve. I skewed the higher torque curve to make it equal to the lower engine torque curve. However, it certainly is possible that the lower engine torque curve, can produce more rear wheel torque if the shape of the high torque curve is altered, yet still matching the criteria.
thoughts?
mk
the last graph is the criteria of the entire discussion. two engines with different torque peaks, yet equal HP. the peak torue and Hp points were also determined by Des . the only interpretation can be the shape of the curve. I skewed the higher torque curve to make it equal to the lower engine torque curve. However, it certainly is possible that the lower engine torque curve, can produce more rear wheel torque if the shape of the high torque curve is altered, yet still matching the criteria.
thoughts?
mk
03-19-2009, 02:44 PM
#322
Three Wheelin'
If the shape of the curve is the same then I do agree that you can produce the same rear wheel torque, but I can't quite wrap my around the viability of ever trying to empirically prove this. I can't come up with a solution that would make this possible. Theoretically it works but I'm not sure this is physically possible. Having two engines with identical shaped curves over different rev ranges, no way.
03-19-2009, 02:54 PM
#323
Rennlist Member
Thread Starter
I just showed you the theoretical example as well as the REAL LIFE example. Ive race both of these cars! (1st two graphs)
Clearly, the lower torque engine has more rear wheel torque at most any vehicle speed! actually, after a gear shift , its about even, but after that, the power and rear wheel torque is in the advantage of the lower torque engine.
Note* shift points for the low torque engin is 5700 to 7700rpm while the high torque engine is 6300 to 4500
The BMW M5 modified curve, vs the caddy showed a more equal senareo.
Dez's is hypothetical, but I'm sure it is possible. It looks more like an electric motor vs a gas engine though.
Can you change your vote now? Or did you vote?
mk
Clearly, the lower torque engine has more rear wheel torque at most any vehicle speed! actually, after a gear shift , its about even, but after that, the power and rear wheel torque is in the advantage of the lower torque engine.
Note* shift points for the low torque engin is 5700 to 7700rpm while the high torque engine is 6300 to 4500
The BMW M5 modified curve, vs the caddy showed a more equal senareo.
Dez's is hypothetical, but I'm sure it is possible. It looks more like an electric motor vs a gas engine though.
Can you change your vote now? Or did you vote?
mk
If the shape of the curve is the same then I do agree that you can produce the same rear wheel torque, but I can't quite wrap my around the viability of ever trying to empirically prove this. I can't come up with a solution that would make this possible. Theoretically it works but I'm not sure this is physically possible. Having two engines with identical shaped curves over different rev ranges, no way.
03-19-2009, 03:00 PM
#325
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This thread is much better when you just look at the pictures.
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Larry Herman
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Larry Herman
2016 Ford Transit Connect Titanium LWB
2018 Tesla Model 3 - Electricity can be fun!
Retired Club Racer & National PCA Instructor
Past Flames:
1994 RS America Club Racer
2004 GT3 Track Car
1984 911 Carrera Club Racer
1974 914/4 2.0 Track Car
CLICK HERE to see some of my ancient racing videos.
03-19-2009, 03:04 PM
#326
No, you're correct it doesn't tell you how often. Torque in this application is pretty much an instantaneous measure. Don't get me wrong I'm not saying that torque is the be all end all, but is essentially half the picture with the other half being the amount of times you replicate it. As its measured through a dyno torque at a certain RPM will be an "average" of the output for that engine speed, but is a direct measure of the output where power is a calculated value telling the rate of that output.
Please correct if I misinterpret your above thought.
A)If you add another cylinder you will increase the net torque output of the crankshaft. So now you've just increased both the net torque and power.
B)If you increase the ignitions by twice haven't you just doubled the engine speed. In which case you've moved this torque value to higher in the rev range and will have halved your power.
Please correct if I misinterpret your above thought.
A)If you add another cylinder you will increase the net torque output of the crankshaft. So now you've just increased both the net torque and power.
B)If you increase the ignitions by twice haven't you just doubled the engine speed. In which case you've moved this torque value to higher in the rev range and will have halved your power.
I don't blame you if you misinterpret me, nor if you think I'm wrong.
A.) Give 2x Torque at same RPM. Torque and Power goes up.
B.) Give 2x RPM and same Torque. RPM and Power goes up.
Both A and B gives the same amount of ignitions = Same amount of combustions. Same amount of combustions with same force, should generate same acceleration.
Of course and I know why you put that there. I just don't want to head into more aspects.
03-19-2009, 03:05 PM
#327
Administrator - "Tyson"
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03-19-2009, 03:07 PM
#328
Rennlist Member
Thread Starter
yeah, but what do they mean? If the point is same engine, and engine speeds, same HP, but one has more torque than the other, certainly the greater torque engine is better because it has more HP down lower. The point of the discussion was to see if that is the rule, and clearly it is not.
I want to see the Y axis values! your BMW I presume???
mk
[QUOTE=Bryan Watts;6397755]I've got graphs.
[QUOTE]
I want to see the Y axis values! your BMW I presume???
mk
[QUOTE=Bryan Watts;6397755]I've got graphs.
[QUOTE]
03-19-2009, 03:19 PM
#329
Three Wheelin'
(You meant double or is this where we disagree?)
I don't blame you if you misinterpret me, nor if you think I'm wrong.
A.) Give 2x Torque at same RPM. Torque and Power goes up.
B.) Give 2x RPM and same Torque. RPM and Power goes up.
Both A and B gives the same amount of ignitions = Same amount of combustions. Same amount of combustions with same force, should generate same acceleration.
I don't blame you if you misinterpret me, nor if you think I'm wrong.
A.) Give 2x Torque at same RPM. Torque and Power goes up.
B.) Give 2x RPM and same Torque. RPM and Power goes up.
Both A and B gives the same amount of ignitions = Same amount of combustions. Same amount of combustions with same force, should generate same acceleration.
Also why Mark commented on my equation earlier, didn't realize I had typed that backwards too.
Wish I had pretty graphs to post
but they're all at home. Maybe later then
03-19-2009, 03:26 PM
#330
Drifting
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Green is a conservative full power tune. Blue is a rain tune. Red is a tune for a specific power/weight class.