HP vs Torque Discussion (No Jokes, No bantering. Just facts and reality)
02-08-2009, 11:24 PM
#62
Rennlist Member
I prefer reading "A Confederacy Of Dunces".
Good seeing you this weekend.
Good seeing you this weekend.
02-08-2009, 11:40 PM
#63
Rennlist Member
02-08-2009, 11:41 PM
#64
Rennlist Member
I'm sorry... I didn't ask a question either, as I assumed a discussion wasn't strictly relegated to someone asking questions, but was also open to someone contributing their opinions, thoughts, or insights.
Please forgive me if I've overstepped my bounds.
Your comment really does make you sound like a sanctimonious asshat, by the way. And I'm Canadian... do you have ANY idea how hard it is for me to say that!?
Please forgive me if I've overstepped my bounds.
Your comment really does make you sound like a sanctimonious asshat, by the way. And I'm Canadian... do you have ANY idea how hard it is for me to say that!?
Des, I said M5 and I meant M5.
Not M3.
02-08-2009, 11:44 PM
#65
Rennlist Member
First off the residual affects of a better launch are felt throughout the acceleration table for any car. The fact that the TT has an AWD launch will have an affect far beyond just 0-60 mph.
Just like we've seen mag tests of the 997 GT3 trap 120 mph and the fastest TT trap we've seen is what 121-122? That hardly suggests what this test does. And the GT3 is far more driver dependant even driving in a straight line.
I'd bet money there isn't one RS that's a legit 7.4 lbs per hp. Porsche left that number the same from the 996's and it's nonsense. They are more like 3220 lbs for the base GT3 and 3180 for the RS. 7.66 to 7.3 hp for the Turbo.
They are not even close to the power/weight ratio that you show, not only that but the DF on the RS makes it less aero dynamic which will take affect at higher speeds.
Just like we've seen mag tests of the 997 GT3 trap 120 mph and the fastest TT trap we've seen is what 121-122? That hardly suggests what this test does. And the GT3 is far more driver dependant even driving in a straight line.
I'd bet money there isn't one RS that's a legit 7.4 lbs per hp. Porsche left that number the same from the 996's and it's nonsense. They are more like 3220 lbs for the base GT3 and 3180 for the RS. 7.66 to 7.3 hp for the Turbo.
They are not even close to the power/weight ratio that you show, not only that but the DF on the RS makes it less aero dynamic which will take affect at higher speeds.
Des, those times in each gear have little to do with a launch from a standing start. They are ROLLING numbers, and reflect reality of the torque advantage the TT has, translating to getting out of the corner faster.
02-08-2009, 11:47 PM
#66
Rennlist Member
I'd like to know how VR managed to get 10 mph faster on any straight anywhere in the CTS-V than the M5, that doesn't sound in the realm of possibility to me. Maybe from an M5 to a Z06, but not to cars that close in acceleration.
I dare bring up the motor trend or whoever it was test with heinreicy vs auberlin in an M5 vs a V and the difference was .4 seconds for the entire lap and maybe 1-3 mph difference on any turn. With the M5 faster in some. I'd need to see data on that one. Besides the M5 is more aero dynamic, better geared for high speeds and really puts the reel in after 100 mph on the V. I usually wont bring up such tests, but a test that includes those two names in their factory cars is hard to ignore.
Not to mention the CTS-V has better brakes by far and arguably the better suspension with the magnetic adjustable suspension. Add to that a pretty substantial hp raise with the extra torque and the only place you could make a case for the BMW is the SMG gearbox which I actually dont like.
I dare bring up the motor trend or whoever it was test with heinreicy vs auberlin in an M5 vs a V and the difference was .4 seconds for the entire lap and maybe 1-3 mph difference on any turn. With the M5 faster in some. I'd need to see data on that one. Besides the M5 is more aero dynamic, better geared for high speeds and really puts the reel in after 100 mph on the V. I usually wont bring up such tests, but a test that includes those two names in their factory cars is hard to ignore.
Not to mention the CTS-V has better brakes by far and arguably the better suspension with the magnetic adjustable suspension. Add to that a pretty substantial hp raise with the extra torque and the only place you could make a case for the BMW is the SMG gearbox which I actually dont like.
The place I observed it was a very short straight between T3 and T4 at Texas World Speedway's 2.9 mile road course. Caddy had 6 speed manual gearbox, M5 had 7 speed electrohydraulic sequential SMG gear box. Both cars were in 3rd gear. Both card understeered like pigs at entry, and yes the Caddy's brakes were slightly better in feel, but not in stopping power (at least for me that day).
02-09-2009, 12:36 AM
#67
Rennlist Member
Thread Starter
Dave,
For some reason you are missing the point again. as a driver, there are many thing that will get you off a corner faster than someone else. There are also many things that will get you off the line, faster. The point that you don’t seem to accept, is that two engines one with grossly more torque than another, CAN, get off a corner the same, or have the same launch abilities. This is for the reasons we all have stated, that you, for some reason, wont concede.
I’ll put another example out there. WHY, because for some reason, you are making the physics of racing more magic. It’s really funny, because one of the reasons drivers are getting faster these days, is because their education level is also improving in all aspects of the dynamics of racing.
Ok, the example. (and hopefully this will summarize it well enough)
Two cars, 400hp each, one 200ft-lbs of torque peak, and one 400ft-lbs of peak torque. redlines 6,000 and 12,000rpm respectively. Gear changes happen at the very common ranges of 50, 90, 120 and 150mph (kind of like GT3 spacing).
1. Road course. off any turn, both cars will have the exact same torque to the rear wheels at any speed, anywhere on the track. This means you have the same accelerative forces at any point on the road course.
2.Drag race. one car will be launching at 3500rpm and the other at 7,000rpm and the torque and modulation to the rear tires would create near the same feel, with forces being identical. There could be some subtle differences in launch that could affect the outcome. kinetic energy in the flywheels might be different enough to make the higher revving clutch dump, or sush box, react differently.
IN both of the above conditions, we are talking about 2 identical cars using two different types of engines. to choose one over the other COULD be in areas of preference of sound, feel and durability.
For some reason, after all this SCIENCE and sound MATH, you don’t seem to understand, because you have not given one bit of logical evidence that you preference for a "higher torque" engine would be better. Again, look no farther than the 24hours of Daytona race were David Donahue was able to fight off in every area of the track, except under braking, the V8 of the top F1 driver JPM. Even the announcers were a little perplexed when their calling of the race, saying that V8 would gain off the turns, and did just the opposite. the flat 6 got off the turn better, and down the straight better. however the differences were subtle. why? with equal weights and many other factors, the rear wheel torque, through the gear boxes were near equal, even though the peak torque values at the engine were very different.
Even today, many racers look at the distance of a car in front of them grow with the length of the straight away. Many forget if someone is .5 seconds in front of you at a curve before a straight at near 50mph, at 150mph down the straight, that distance will be 3x. so if you are 1 car length behind, you might be 3 car lengths behind. On the same token, under braking, you might think you are catching up, but the time apart might be the same. Things like that still seem confuse racers and announcers even to this day!
When we start talking about race car preference, you have a valid point. each car will have qualities that each of us as drivers would like or dislike. IN the end, when the physics is taken into account, they are classed properly by the rules makers.
mk
For some reason you are missing the point again. as a driver, there are many thing that will get you off a corner faster than someone else. There are also many things that will get you off the line, faster. The point that you don’t seem to accept, is that two engines one with grossly more torque than another, CAN, get off a corner the same, or have the same launch abilities. This is for the reasons we all have stated, that you, for some reason, wont concede.
I’ll put another example out there. WHY, because for some reason, you are making the physics of racing more magic. It’s really funny, because one of the reasons drivers are getting faster these days, is because their education level is also improving in all aspects of the dynamics of racing.
Ok, the example. (and hopefully this will summarize it well enough)
Two cars, 400hp each, one 200ft-lbs of torque peak, and one 400ft-lbs of peak torque. redlines 6,000 and 12,000rpm respectively. Gear changes happen at the very common ranges of 50, 90, 120 and 150mph (kind of like GT3 spacing).
1. Road course. off any turn, both cars will have the exact same torque to the rear wheels at any speed, anywhere on the track. This means you have the same accelerative forces at any point on the road course.
2.Drag race. one car will be launching at 3500rpm and the other at 7,000rpm and the torque and modulation to the rear tires would create near the same feel, with forces being identical. There could be some subtle differences in launch that could affect the outcome. kinetic energy in the flywheels might be different enough to make the higher revving clutch dump, or sush box, react differently.
IN both of the above conditions, we are talking about 2 identical cars using two different types of engines. to choose one over the other COULD be in areas of preference of sound, feel and durability.
For some reason, after all this SCIENCE and sound MATH, you don’t seem to understand, because you have not given one bit of logical evidence that you preference for a "higher torque" engine would be better. Again, look no farther than the 24hours of Daytona race were David Donahue was able to fight off in every area of the track, except under braking, the V8 of the top F1 driver JPM. Even the announcers were a little perplexed when their calling of the race, saying that V8 would gain off the turns, and did just the opposite. the flat 6 got off the turn better, and down the straight better. however the differences were subtle. why? with equal weights and many other factors, the rear wheel torque, through the gear boxes were near equal, even though the peak torque values at the engine were very different.
Even today, many racers look at the distance of a car in front of them grow with the length of the straight away. Many forget if someone is .5 seconds in front of you at a curve before a straight at near 50mph, at 150mph down the straight, that distance will be 3x. so if you are 1 car length behind, you might be 3 car lengths behind. On the same token, under braking, you might think you are catching up, but the time apart might be the same. Things like that still seem confuse racers and announcers even to this day!
When we start talking about race car preference, you have a valid point. each car will have qualities that each of us as drivers would like or dislike. IN the end, when the physics is taken into account, they are classed properly by the rules makers.
mk
02-09-2009, 12:48 AM
#69
Rennlist Member
Thread Starter
What you forget to realize is that the RS vs Turbo comparison is a great case for when greater (engine) torque rules when talking about the same type or redline rpm). The point of this, is it doesnt make it the rule!. It happens, in real life, more often than not. You forget that this is not a see who is smarter competition, nor a case for HP rating numbers being the end all catch all measure of a cars performance. Nor is it ment to discount torque found at the engine when doing a comparison. (as long as you can do a bunch of muliplicaton and little bit of calculus in your head. ) Its to understand that the HP number has to be compared as a curve.
You can also look at torque numbers, but if you are not comparing equal redlines, then the comparison is not really possible.
The reason the 997TT is so much faster, is because of a broader HP curve. Yes it is due to more peak torque at the engine too, but we are talking about two engines with near equal redlines. There are just as many stories , like even my car, especially now, with a flat HP curve, and not so much a impressive torque number, in fact, its a pretty dramatic falling torque curve. But, having 350hp at 4500rpm to 6500rpm gives me a lot more over all torque at the rear wheels than a GT3 with only the same peak HP. It also has a lot more over the 5500rpm chevy's with more torque and a peaky hp curve as well!
The porsche TT has much more HP, but with the weight , the ratio is much closer. the reason for the differnence in performance is due to the broader HP curve. and because we are talking about two equal types of engines, its due to the greater torque value. Just to restate just in case I wasnt making my point clear above.
By the way, your statement could be correct, but that is not the point here.
mk
You can also look at torque numbers, but if you are not comparing equal redlines, then the comparison is not really possible.
The reason the 997TT is so much faster, is because of a broader HP curve. Yes it is due to more peak torque at the engine too, but we are talking about two engines with near equal redlines. There are just as many stories , like even my car, especially now, with a flat HP curve, and not so much a impressive torque number, in fact, its a pretty dramatic falling torque curve. But, having 350hp at 4500rpm to 6500rpm gives me a lot more over all torque at the rear wheels than a GT3 with only the same peak HP. It also has a lot more over the 5500rpm chevy's with more torque and a peaky hp curve as well!
The porsche TT has much more HP, but with the weight , the ratio is much closer. the reason for the differnence in performance is due to the broader HP curve. and because we are talking about two equal types of engines, its due to the greater torque value. Just to restate just in case I wasnt making my point clear above.
By the way, your statement could be correct, but that is not the point here.
mk
02-09-2009, 01:42 AM
#71
Rennlist Member
Thread Starter
I wonder which car he (VR) would pick of the two below. I'll gie him a hint. These are HP curves, and the formula for HP is HP=torque x rpm/5250
Any idea which one has the greater engine torque? which one would "get off the turns" better?
mk
Any idea which one has the greater engine torque? which one would "get off the turns" better?
mk
02-09-2009, 10:13 AM
#73
Rennlist Member
02-09-2009, 10:23 AM
#74
Rennlist Member
02-09-2009, 11:57 AM
#75