Power to weight ratio vs weight distribution vs aerodynamics
Discussion
For people who don't know much about cars, they normally think it's all about BHP. A more powerful car will always be faster.
For those who understand some, they know power to weight ratio is what needs to be considered instead of only power.
But there is obviously more to it than that.
For example, take two quite similar cars. At least they have more similarities than differences. The Corvette and a TVR Sagaris.
The Sagaris weighs close to nothing and has an engine as powerful as the base Corvette. Yet, the Sagaris is not as fast. On paper it absolutely should be.
The Sagaris published performance and data is:
Curb weight: 1,078 kg (2,376 lb)
406 BHP
Top speed: 298 km/h (185 mph)
0 to 60 mph: 3.7 seconds
The Corvette Z06 is:
Curb weight: 1,420 kg (3,131 lb)
505 BHP
Top speed: 317 km/h (197 mph)
0 to 60 mph: 3.6 seconds
The Sagaris has superior power to weight ratio and yet is still slower. The Corvette besides heavier is also a bit larger all around. The 0-60 is close. But given the weight advantage the Sagaris should beat the Corvette. In the top speed the Corvette is undoubtedly faster.
Even compared to the base Corvette, it doesn't do bad against the Sagaris considering the huge weight advantage for the Sagaris. The base Corvette is much heavier, produce "less" power but is still faster in the top end:
Curb weight: 1470 kg (3241 lbs)
405 BHP
Top speed: 306 kph (190 mph)
0 to 60 mph (97 km/h):4.5 seconds
0 to 60 the Sagaris is a bit quicker. But then again it's 27% lighter.
Considering that, it's obvious power to weight ratio is not THE deciding factor.
Thinking of why the Sagaris performs worse than the Corvette even though it has a good power to weight advantage, the first thing which came to mind was aerodynamics. I know that at around 320 km/h (200 mph) aerodynamics plays a major role and every extra speed dot takes a humongous amount of work to achieve. It being a TVR, I thought the body was just designed to look cool and nothing else. I doubted they had money for wind tunnel tests. But as it turns out the Sagaris seem to have been the first TVR which actually used wind tunnels tests and the body work aerodynamics is all functional and supposedly good.
Then my next thought was weight distribution. The Corvette has had nearly perfect weight distribution for the last 4 generations. I have no idea what the Sagaris weight distribution is, but maybe it's not that good and it just doesn't put the power down to the ground very efficiently? Because otherwise it's puzzling. The Sagaris got good reviews for its performance. So despite having never driven one, I don't think it's because it sucks.
I know other things like gearing etc as well as driver skill will play a role. But the power to weight ratio is stacked quite considerably towards the Sagaris.
By the way, I'm comparing the Sagaris to its contemporary Corvette. Not the latest generation C7. I'm comparing it to the C6. So the answer can't be just, the Corvette is more technologically advanced.
It's true any Corvette of the modern era has more electronics than the Sagaris, which doesn't even have ABS. But I would think the Sagaris performance numbers were obtained by a professional driver where this would make less difference. I don't know if the Corvette results were obtained with electronic aids off or not. But many magazines and testers turn them off for such tests. And I'm sure they were at least manual transmission cars. Besides the C6 is hardly an electronics marvel. The Corvette and TVRs are very similar concepts. Simple, plain, honest sports cars. GM does have more money. But the Sagaris has the specs stacked in its favor.
I have never seen a track lap comparison between a Sagaris and any Corvette C6s. But I think it's a safe bet the Corvette would lap faster. It lapped faster than a Porsche 911.
So what would you say plays a bigger role? Power to weight ratio, aerodynamics or even weight distribution? I don't even mean in the case of this comparison only, but in general.
For those who understand some, they know power to weight ratio is what needs to be considered instead of only power.
But there is obviously more to it than that.
For example, take two quite similar cars. At least they have more similarities than differences. The Corvette and a TVR Sagaris.
The Sagaris weighs close to nothing and has an engine as powerful as the base Corvette. Yet, the Sagaris is not as fast. On paper it absolutely should be.
The Sagaris published performance and data is:
Curb weight: 1,078 kg (2,376 lb)
406 BHP
Top speed: 298 km/h (185 mph)
0 to 60 mph: 3.7 seconds
The Corvette Z06 is:
Curb weight: 1,420 kg (3,131 lb)
505 BHP
Top speed: 317 km/h (197 mph)
0 to 60 mph: 3.6 seconds
The Sagaris has superior power to weight ratio and yet is still slower. The Corvette besides heavier is also a bit larger all around. The 0-60 is close. But given the weight advantage the Sagaris should beat the Corvette. In the top speed the Corvette is undoubtedly faster.
Even compared to the base Corvette, it doesn't do bad against the Sagaris considering the huge weight advantage for the Sagaris. The base Corvette is much heavier, produce "less" power but is still faster in the top end:
Curb weight: 1470 kg (3241 lbs)
405 BHP
Top speed: 306 kph (190 mph)
0 to 60 mph (97 km/h):4.5 seconds
0 to 60 the Sagaris is a bit quicker. But then again it's 27% lighter.
Considering that, it's obvious power to weight ratio is not THE deciding factor.
Thinking of why the Sagaris performs worse than the Corvette even though it has a good power to weight advantage, the first thing which came to mind was aerodynamics. I know that at around 320 km/h (200 mph) aerodynamics plays a major role and every extra speed dot takes a humongous amount of work to achieve. It being a TVR, I thought the body was just designed to look cool and nothing else. I doubted they had money for wind tunnel tests. But as it turns out the Sagaris seem to have been the first TVR which actually used wind tunnels tests and the body work aerodynamics is all functional and supposedly good.
Then my next thought was weight distribution. The Corvette has had nearly perfect weight distribution for the last 4 generations. I have no idea what the Sagaris weight distribution is, but maybe it's not that good and it just doesn't put the power down to the ground very efficiently? Because otherwise it's puzzling. The Sagaris got good reviews for its performance. So despite having never driven one, I don't think it's because it sucks.
I know other things like gearing etc as well as driver skill will play a role. But the power to weight ratio is stacked quite considerably towards the Sagaris.
By the way, I'm comparing the Sagaris to its contemporary Corvette. Not the latest generation C7. I'm comparing it to the C6. So the answer can't be just, the Corvette is more technologically advanced.
It's true any Corvette of the modern era has more electronics than the Sagaris, which doesn't even have ABS. But I would think the Sagaris performance numbers were obtained by a professional driver where this would make less difference. I don't know if the Corvette results were obtained with electronic aids off or not. But many magazines and testers turn them off for such tests. And I'm sure they were at least manual transmission cars. Besides the C6 is hardly an electronics marvel. The Corvette and TVRs are very similar concepts. Simple, plain, honest sports cars. GM does have more money. But the Sagaris has the specs stacked in its favor.
I have never seen a track lap comparison between a Sagaris and any Corvette C6s. But I think it's a safe bet the Corvette would lap faster. It lapped faster than a Porsche 911.
So what would you say plays a bigger role? Power to weight ratio, aerodynamics or even weight distribution? I don't even mean in the case of this comparison only, but in general.
Edited by SPKR on Saturday 13th January 00:29
Perhaps TVRs never made much like the claimed power ... I'd add a knowing-wink smiley, but it's true.
Also, since power required to overcome drag rises with the cube of speed - top-end acceleration and ultimate top speed have very, very much more to do with outright power than weight. At any weight.
Example: I've a 420Kg BEC with c.170hp, which on paper is comparable with either example above.
And so, up to 80-90, and if I can get the power down /a good launch, it could beat either of the above to 60, maybe 90.. ish; certainly I've seen better times.
But above that forget it: even with tiny mass, tiny frontal area and even a very small Cd*A number - I simply don't have the excess power to swamp aero drag in the same way. At 100 all 3 cars will require 55-70hp to overcome their cumulative (aero+frictonal) drag: at which point I have perhaps 80-90bhp in hand to accelerate me+car (500kg); the TVR an optimistic amount more, let's just say 'some': and the Corvette perhaps c.400 (but 3x my all-up mass thus, at ~100mph, perhaps 1.6x my effective P:W ratio).
It's simple maths, really: if you want high speed, high-HP romps away*. 'Static' P:W, and the car's weight balance have very little to do with it. My 2p.
ETA: in small light, low-powered cars therefore, aero is a big deal: one of the reasons Fisher Furys and Sylva Phoenixes dominated RGB racing within two seasons is that - compared with '7's of comparable weight and power - the wheel-enclosing body shells of the former meant as much as +15 to even 20mph difference at the end of under-1/2mile straights: a big deal!
Also, since power required to overcome drag rises with the cube of speed - top-end acceleration and ultimate top speed have very, very much more to do with outright power than weight. At any weight.
Example: I've a 420Kg BEC with c.170hp, which on paper is comparable with either example above.
And so, up to 80-90, and if I can get the power down /a good launch, it could beat either of the above to 60, maybe 90.. ish; certainly I've seen better times.
But above that forget it: even with tiny mass, tiny frontal area and even a very small Cd*A number - I simply don't have the excess power to swamp aero drag in the same way. At 100 all 3 cars will require 55-70hp to overcome their cumulative (aero+frictonal) drag: at which point I have perhaps 80-90bhp in hand to accelerate me+car (500kg); the TVR an optimistic amount more, let's just say 'some': and the Corvette perhaps c.400 (but 3x my all-up mass thus, at ~100mph, perhaps 1.6x my effective P:W ratio).
It's simple maths, really: if you want high speed, high-HP romps away*. 'Static' P:W, and the car's weight balance have very little to do with it. My 2p.
ETA: in small light, low-powered cars therefore, aero is a big deal: one of the reasons Fisher Furys and Sylva Phoenixes dominated RGB racing within two seasons is that - compared with '7's of comparable weight and power - the wheel-enclosing body shells of the former meant as much as +15 to even 20mph difference at the end of under-1/2mile straights: a big deal!
- and that's fine by me, I don't care about that end anyway; my playground is tight -winding B-road, and ultimate fidelity in feedback
Edited by Huff on Saturday 13th January 00:47
Through my vast history of cars, ive always found that power to weight is key.
My superturbodiesel on a 300whp tune would marginally beat a V8 M3, because it was a few hundred kilos lighter.
But my old big powered 2 tonne barges (400-500bhp) wouldnt be that far in front of a hot hatch.
So yeah power to weight is the definition of speed or quickness in my book.
However i have noticed that lighter cars that would trance a big barge under 100mph tend to back off at higher speeds. Smaller turbos getting hot? Of just not enough weight to cut through the air? Maybe.
Once you get into fettled C6 RS6 territory (850-900bhp) the 2 tonne i feel is just irrelevant for the most part. 450bhp /tonne in a road car is mental.
My superturbodiesel on a 300whp tune would marginally beat a V8 M3, because it was a few hundred kilos lighter.
But my old big powered 2 tonne barges (400-500bhp) wouldnt be that far in front of a hot hatch.
So yeah power to weight is the definition of speed or quickness in my book.
However i have noticed that lighter cars that would trance a big barge under 100mph tend to back off at higher speeds. Smaller turbos getting hot? Of just not enough weight to cut through the air? Maybe.
Once you get into fettled C6 RS6 territory (850-900bhp) the 2 tonne i feel is just irrelevant for the most part. 450bhp /tonne in a road car is mental.
Huff said:
Perhaps TVRs never made much like the claimed power ... I'd add a knowing-wink smiley, but it's true.
Also, since power required to overcome drag rises with the cube of speed - top-end acceleration and ultimate top speed have very, very much more to do with outright power than weight. At any weight.
Example: I've a 420Kg BEC with c.170hp, which on paper is comparable with either example above.
And so, up to 80-90, and if I can get the power down /a good launch, it could beat either of the above to 60, maybe 90.. ish; certainly I've seen better times.
But above that forget it: even with tiny mass, tiny frontal area and even a very small Cd*A number - I simply don't have the excess power to swamp aero drag in the same way. At 100 all 3 cars will require 55-70hp to overcome their cumulative (aero+frictonal) drag: at which point I have perhaps 80-90bhp in hand to accelerate me+car (500kg); the TVR an optimistic amount more, let's just say 'some': and the Corvette perhaps c.400 (but 3x my all-up mass thus, at ~100mph, perhaps 1.6x my effective P:W ratio).
It's simple maths, really: if you want high speed, high-HP romps away*. 'Static' P:W, and the car's weight balance have very little to do with it. My 2p.
ETA: in small light, low-powered cars therefore, aero is a big deal: one of the reasons Fisher Furys and Sylva Phoenixes dominated RGB racing within two seasons is that - compared with '7's of comparable weight and power - the wheel-enclosing body shells of the former meant as much as +15 to even 20mph difference at the end of under-1/2mile straights: a big deal!
What you say makes a lot of sense. Also, since power required to overcome drag rises with the cube of speed - top-end acceleration and ultimate top speed have very, very much more to do with outright power than weight. At any weight.
Example: I've a 420Kg BEC with c.170hp, which on paper is comparable with either example above.
And so, up to 80-90, and if I can get the power down /a good launch, it could beat either of the above to 60, maybe 90.. ish; certainly I've seen better times.
But above that forget it: even with tiny mass, tiny frontal area and even a very small Cd*A number - I simply don't have the excess power to swamp aero drag in the same way. At 100 all 3 cars will require 55-70hp to overcome their cumulative (aero+frictonal) drag: at which point I have perhaps 80-90bhp in hand to accelerate me+car (500kg); the TVR an optimistic amount more, let's just say 'some': and the Corvette perhaps c.400 (but 3x my all-up mass thus, at ~100mph, perhaps 1.6x my effective P:W ratio).
It's simple maths, really: if you want high speed, high-HP romps away*. 'Static' P:W, and the car's weight balance have very little to do with it. My 2p.
ETA: in small light, low-powered cars therefore, aero is a big deal: one of the reasons Fisher Furys and Sylva Phoenixes dominated RGB racing within two seasons is that - compared with '7's of comparable weight and power - the wheel-enclosing body shells of the former meant as much as +15 to even 20mph difference at the end of under-1/2mile straights: a big deal!
- and that's fine by me, I don't care about that end anyway; my playground is tight -winding B-road, and ultimate fidelity in feedback
Edited by Huff on Saturday 13th January 00:47
Like I said, I know that at high speeds it takes a lot of power to beat wind.
It would be ok if the Corvette beat the Sagaris only on top speed but not acceleration. That would even make sense. But that's not the case. It is slightly faster at 0-60 than the Sagaris and it just shouldn't be.
So I guess the explanation can only be what you said. The Sagaris is not making as much power as publicized. Or it weighs much more.
Palmers said:
Through my vast history of cars, ive always found that power to weight is key.
My superturbodiesel on a 300whp tune would marginally beat a V8 M3, because it was a few hundred kilos lighter.
But my old big powered 2 tonne barges (400-500bhp) wouldnt be that far in front of a hot hatch.
So yeah power to weight is the definition of speed or quickness in my book.
However i have noticed that lighter cars that would trance a big barge under 100mph tend to back off at higher speeds. Smaller turbos getting hot? Of just not enough weight to cut through the air? Maybe.
Once you get into fettled C6 RS6 territory (850-900bhp) the 2 tonne i feel is just irrelevant for the most part. 450bhp /tonne in a road car is mental.
Well, the Sagaris has almost that. It weighs just a bit more than a ton and makes just a bit less than 450bhp, supposedly. My superturbodiesel on a 300whp tune would marginally beat a V8 M3, because it was a few hundred kilos lighter.
But my old big powered 2 tonne barges (400-500bhp) wouldnt be that far in front of a hot hatch.
So yeah power to weight is the definition of speed or quickness in my book.
However i have noticed that lighter cars that would trance a big barge under 100mph tend to back off at higher speeds. Smaller turbos getting hot? Of just not enough weight to cut through the air? Maybe.
Once you get into fettled C6 RS6 territory (850-900bhp) the 2 tonne i feel is just irrelevant for the most part. 450bhp /tonne in a road car is mental.
OP - the other thing is - the difference between claiming,say, sub4.5s to 60 (a useless measure really) and actually achieving it always has so much more to do with traction and surface and dryness and consistency of launch (and gear changes if reqd) than anything else: put it this way - once you are aiming below, say 5ish, actual P:W has little to do with it. Which is why, for example, DSG boxes show an advantage that is disproportionate - simply from just being more consistent than a human with a manual. Equally, you can bias a 'headline' number here by choosing gearing that is flatteringly-short to the point of actually spoiling on-road performance by then requiring gearchanges in the range you'd really like to just exploit the engine rev range instead on an A-road...
0-60 has little to do with useful on-road performance. Over 30yrs ago LJK Setright observed a really fast car covers 60-90 in the same time as its nominal 0-60. That's still a really good measure of real capability IMO. (and, as I said - beyond that, personally I'm not so much interested)
0-60 has little to do with useful on-road performance. Over 30yrs ago LJK Setright observed a really fast car covers 60-90 in the same time as its nominal 0-60. That's still a really good measure of real capability IMO. (and, as I said - beyond that, personally I'm not so much interested)
This is my understanding (so may be poppycock!)
Power to weight is more to do with acceleration, not so much about top speed.
Top speed is about power, gearing and aerodynamics but the biggest one is the gearing. If the car has the immense power but a short ratio gearbox it's top speed will never be that high. Conversely, with two identical cars, one with 500hp and one with 1000hp, both will have the same top speed (limited by the gearbox) but the 1000hp car will get there more quickly.
Aero gets involved when the gearing is so long that the cars top speed via the gearbox is higher than the power level can reach, so a 200mph gearbox in a 130hp car will run into aero problems, whilst the same gearbox in the same car but now with 1000hp will reach 200mph easily, almost ignoring the aero effect due to sheer power.
I think I've got that right anyway.
Power to weight is more to do with acceleration, not so much about top speed.
Top speed is about power, gearing and aerodynamics but the biggest one is the gearing. If the car has the immense power but a short ratio gearbox it's top speed will never be that high. Conversely, with two identical cars, one with 500hp and one with 1000hp, both will have the same top speed (limited by the gearbox) but the 1000hp car will get there more quickly.
Aero gets involved when the gearing is so long that the cars top speed via the gearbox is higher than the power level can reach, so a 200mph gearbox in a 130hp car will run into aero problems, whilst the same gearbox in the same car but now with 1000hp will reach 200mph easily, almost ignoring the aero effect due to sheer power.
I think I've got that right anyway.
As above, gearing is going to play a significant part in it; aerodynamics to 60mph less so unless you're comparing cars at the extreme ends of the spectrum.
The idea that a 50:50 weight distribution for a car is somehow "automotive perfection" was just a marketing tag line dreamed up by BMW, but it stuck and became "fact".
SPKR said:
Then my next thought was weight distribution. The Corvette has had nearly perfect weight distribution for the last 4 generations.
Perfect weight distribution? For straight line acceleration in a RWD car you want the mass as much to the rear as possible to gain the most traction from the driven wheels, in which case the original Beetle has better weight distribution than the Corvette when it comes to chasing 0-60 times.The idea that a 50:50 weight distribution for a car is somehow "automotive perfection" was just a marketing tag line dreamed up by BMW, but it stuck and became "fact".
I think Huff has covered this very well above.
Incidentally, even based on the published numbers in the OP, the Sagaris has a power:weight ratio only 6% better than the Z06. That's a very small difference, it doesn't seem that surprising it's swamped by all the other factors mentioned so far.
The powerband could be another factor - the power:weight is based on power at peak power rpm, but you sweep through a range of rpms as you go up through the gears. If the Z06 has a flatter powerband (quite likely with a SBC), it could have a higher average hp compared to peak than the Sagaris.
Finally, this thread brings to mind a story told by I think Autocar. Chevy had just launched a new Vette. Our man went to them and said, 'great car, but we can't match your 0-60 time'. GM assured the journo that their factory drivers had genuinely achieved the claimed time. The journo was skeptical, so GM dispatched one of their guys, who took off in 1st and then slammed the car into 2nd while holding his right foot flat on the throttle. At 60mph the timing gear flashed up exactly GM's claimed time, which Autocar duly printed. Just an example of what Huff refers to about differences in technique, gear changes etc.
Incidentally, even based on the published numbers in the OP, the Sagaris has a power:weight ratio only 6% better than the Z06. That's a very small difference, it doesn't seem that surprising it's swamped by all the other factors mentioned so far.
The powerband could be another factor - the power:weight is based on power at peak power rpm, but you sweep through a range of rpms as you go up through the gears. If the Z06 has a flatter powerband (quite likely with a SBC), it could have a higher average hp compared to peak than the Sagaris.
Finally, this thread brings to mind a story told by I think Autocar. Chevy had just launched a new Vette. Our man went to them and said, 'great car, but we can't match your 0-60 time'. GM assured the journo that their factory drivers had genuinely achieved the claimed time. The journo was skeptical, so GM dispatched one of their guys, who took off in 1st and then slammed the car into 2nd while holding his right foot flat on the throttle. At 60mph the timing gear flashed up exactly GM's claimed time, which Autocar duly printed. Just an example of what Huff refers to about differences in technique, gear changes etc.
Come to the first corner and he's braking later, cornering faster and accelerating harder out the other side.Good midnight contemplating OP.
Higher power to rate ratio will provided quicker change in speed and the lighter car will stop, turn and move its inertia quicker.
Also remember that BHP is max power from an engine around 7000RPM for example so when are car accelerates 0-60 the engine starts at low RPM and low BHP.
So 0-60 figures aren't the benchmark for how fast a car is. As mentioned gearing, road surface, lower torque, 4wd, driver etc have more effect on 0-60.
For example the Lotus Carlton with 380bhp has a claim 0-60 over 5 seconds. This will most likely be a quicker once moving than most hot hatches with a claimed quicker 0-60
Higher power to rate ratio will provided quicker change in speed and the lighter car will stop, turn and move its inertia quicker.
Also remember that BHP is max power from an engine around 7000RPM for example so when are car accelerates 0-60 the engine starts at low RPM and low BHP.
So 0-60 figures aren't the benchmark for how fast a car is. As mentioned gearing, road surface, lower torque, 4wd, driver etc have more effect on 0-60.
For example the Lotus Carlton with 380bhp has a claim 0-60 over 5 seconds. This will most likely be a quicker once moving than most hot hatches with a claimed quicker 0-60
Good posts above, I agree
Top speed is determined by a battle of power against drag assuming the manufacturer has fitted the correct gearing. For a high top speed you want high power, low drag and a small frontal area.
In gear acceleration from a steady speed is related to torque to weight ratio.
Flat out acceleration through the gears from 20 mph or so is related to power to weight ratio.
O to 60 time is related to power to weight but is limited by traction, and this is where weight distribution is vital in a two wheel drive car.
Top speed is determined by a battle of power against drag assuming the manufacturer has fitted the correct gearing. For a high top speed you want high power, low drag and a small frontal area.
In gear acceleration from a steady speed is related to torque to weight ratio.
Flat out acceleration through the gears from 20 mph or so is related to power to weight ratio.
O to 60 time is related to power to weight but is limited by traction, and this is where weight distribution is vital in a two wheel drive car.
delta0 said:
Top speed is about power and resistance (aerodynamics, rolling resistance etc.). Acceleration is about grip, power and weight.
bottom end acceleration is all about grip, power and weight.As aerodynamic drag begins to build up, the amount of power 'left over' for acceleration is reduced.
Obviously, a car that only has sufficient power to do 120mph against its aerodynamic drag will be suffering sluggish acceleration by the time it reaches 90-100mph, no matter how good its power:weight ratio is. Something like a 130bhp Locaterfield being the extreme example of this: you might be getting 0-60 in 6 seconds, but 0-100 is measured on a geological timescale.
I have a 350bhp per ton M5, golf R with around 250bhp per ton and a Zenos E10R with around 500bhp per ton.
All 3 would probably pass the 1/4mile at virtually the same time but at varying speeds.
Traction/inertia is important for getting off the line.
The torque plateau and dual clutch of modern cars (particularly VAG cars) make relentless acceleration really punch well above there weight.
The drag on the Zenos above 90 really does have an effect on the acceleration.
Take a look at this video of a similar powered M5 as mine vs a pagini with similar power if not more but probably 700kg lighter!! Pretty hard to explain...
https://youtu.be/brftSvZpPtc
D = (Cd x ((? x V^2) / 2) x A ) + (d-rolling x V) + d-static
Ttyre = (Pengine - Plosses) / V
Ftyre = MIN ( Fnormal x ?(tyre) || Ttyre / Rtyre )
Fvehicle = Ftyre - D
Avehicle = Mvehicle / Fvehicle
Simples ;-)
(in fact, it is simple; Power to Weight matters when you are going slowly and Power to Drag matters when you are going fast! )
Ttyre = (Pengine - Plosses) / V
Ftyre = MIN ( Fnormal x ?(tyre) || Ttyre / Rtyre )
Fvehicle = Ftyre - D
Avehicle = Mvehicle / Fvehicle
Simples ;-)
(in fact, it is simple; Power to Weight matters when you are going slowly and Power to Drag matters when you are going fast! )
Edited by anonymous-user on Saturday 13th January 14:39
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