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Errr... Really??

It's physics... Newton's laws of Gravity don't apply to cars huh?! Your trying to say that two cars created equally in every way, one weighing a thousand pounds more than the other will have the same top speed? Really?
Heh, you are right, it is physics. While gravity applies to cars, at these speeds aerodynamics take over similar to how they take over for airplanes. These are landing/takeoff speeds for most aircraft you know, right? We can really make a scientific study of these physics if you want but here's some brief introduction:

I'll quote wikipedia because their description is very accurate: Drag Force Equation

You (or someone else above) brought up the Bugatti Veyron and this little thread gives a lot of insight into how terrible that particular vehicle is to look at relative to this discussion of top speed. That vehicle is a brute force attack on top speed, but even the Bugatti uses sails to break from top speed as flaps pop up when you're trying to break, other cars do this. Other vehicles, with much less power, are able to top out nearly as high as a Veyron because they are better engineered for aerodynamics. More power helps but aero is the key.

A large part of aerodynamic design in cars is to actually creat downforce. This is something which your higher weight vehicle actually accomplishes from the get-go before aerodynamics kick inf or real. The point there is to plant the wheels down and to NOT turn into an airplane at the first bump.

I'll give you another example, take a motorcycle and a Corvette with similar power ratings. It is fairly easy to turbocharge a Hayabusa to 500 hp. The power to weight ratio is absolutely astounding on motorcycles. This is why they are so quick off the line if you can keep the front wheel down, about 8 years ago the
. When you start approaching top speeds you'll find that the Corvette which is a much heavier vehicle (by a factor of 6 times heavier) can top out at a higher speed unless the rider of the motorcycle tucks in extremely well. The problem is that humans are not aerodynamic, if we were shaped like whales or sharks we might suffer better in the wind... Notice motorcycle road racing like MotoGP, they get tucked in on the straightaways, this is not just to shield the rider from the wind, as they approach the corner the riders actually stand up into the wind at top speed and their bodies serve as air-breaks which almost immediately kill 10-30mph. Those bikes top out at 200+mph constantly, but if you consider power to wieght ratios they should be doing much more... saidly aerodynamics is the culprit.

You are right about one thing, in the real world weight matters due to rolling friction and etc, you'll find out that those differences are very negligent when you approach true aerodynamically limited top speed. In other words, a good tail wind will have much bigger bearing on your top speed rather than how many passengers you fit into your car.

Hope that helps a bit in the discussion and I haven't offended anyone with my physics.
 

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I could easily see 800lbs difference between say the 2nd gen SuperBee or Core 300 vs a SRT loaded with passengers. I'm guessing top speed will still be pretty close, or will it have dropped by 5mph or more? I'm not suggesting anyone should do it, but the only way to find out is get the top speed in the same car with and without passengers.
Given the same conditions and blowing the tires up to allow for the extra weight causing tire friction... No difference worth talking about. It would need to be some pretty big weight to cause enough rolling friction to slow it down. If two vehicles share the same power and drag coefficient and have gearing between the diff and transmission to equal a similar final drive ratio then in theory they should do the same top speed even if one is 800lbs off given enough room to do it, the heavier car will take longer to get there. They actually weigh cars down on the salt flats to help counteract lift and aid traction... Takes longer to get the job done... But they get there.

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They actually weigh cars down on the salt flats to help counteract lift and aid traction... Takes longer to get the job done... But they get there.
Oh great example, how could I forget that one. One of the least intuitive things until you actually try to wrap your brain around what determines top speed.
 

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Heh, you are right, it is physics. While gravity applies to cars, at these speeds aerodynamics take over similar to how they take over for airplanes. These are landing/takeoff speeds for most aircraft you know, right? We can really make a scientific study of these physics if you want but here's some brief introduction:

I'll quote wikipedia because their description is very accurate: Drag Force Equation

You (or someone else above) brought up the Bugatti Veyron and this little thread gives a lot of insight into how terrible that particular vehicle is to look at relative to this discussion of top speed. That vehicle is a brute force attack on top speed, but even the Bugatti uses sails to break from top speed as flaps pop up when you're trying to break, other cars do this. Other vehicles, with much less power, are able to top out nearly as high as a Veyron because they are better engineered for aerodynamics. More power helps but aero is the key.

A large part of aerodynamic design in cars is to actually creat downforce. This is something which your higher weight vehicle actually accomplishes from the get-go before aerodynamics kick inf or real. The point there is to plant the wheels down and to NOT turn into an airplane at the first bump.

I'll give you another example, take a motorcycle and a Corvette with similar power ratings. It is fairly easy to turbocharge a Hayabusa to 500 hp. The power to weight ratio is absolutely astounding on motorcycles. This is why they are so quick off the line if you can keep the front wheel down, about 8 years ago the Kawasaki Ninja zx10r was hitting 100+mph in first gear in about 4 seconds. When you start approaching top speeds you'll find that the Corvette which is a much heavier vehicle (by a factor of 6 times heavier) can top out at a higher speed unless the rider of the motorcycle tucks in extremely well. The problem is that humans are not aerodynamic, if we were shaped like whales or sharks we might suffer better in the wind... Notice motorcycle road racing like MotoGP, they get tucked in on the straightaways, this is not just to shield the rider from the wind, as they approach the corner the riders actually stand up into the wind at top speed and their bodies serve as air-breaks which almost immediately kill 10-30mph. Those bikes top out at 200+mph constantly, but if you consider power to wieght ratios they should be doing much more... saidly aerodynamics is the culprit.

You are right about one thing, in the real world weight matters due to rolling friction and etc, you'll find out that those differences are very negligent when you approach true aerodynamically limited top speed. In other words, a good tail wind will have much bigger bearing on your top speed rather than how many passengers you fit into your car.

Hope that helps a bit in the discussion and I haven't offended anyone with my physics.
Your not offending me at all.. I was actually agreeing with you... ;) I was just saying that in the real world there are other factors that will change things a little and weight will be one (but only from the friction it causes on other components) Which is undoubtedly negligible, but there nonetheless... I was the one saying a drag limited car is a drag limited car... Unless you throw a ton of power at it or reduce enough weight to remove a great deal of rolling friction then its not getting much faster! If I wasn't clear about that earlier... Apologies... I was using a little dry sarcasm in my last post... But not directed at you! Lol..

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He does let off the gas. When you pass him, his mph dropped a lot. Did you peg your speedo? Our cars are supposed to be drag limited to about 175 mph.
Can't believe everything the manufacturer states. I done 177, 182, and 184....more to follow as I just ran out of road.
 

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Also talked to the owner of an E-Force at length yesterday and also said that his blower overheats (as stated by the OP) and the computer pulls crazy timing until it cools...looks like NA for me.


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Dont get discouraged superchargers only heats up when ur in boost for looooong period of time.. Otherwise it's ALOT of fun imagine having 100 shot nitrous ALL the time:shocked:

I see in that video they are in the desert so it must of been very hot on that blower i also seen in that video the ctsv boost gauge was pegged all the way to max stock cts gauge only go to maybe about half way i think.. so it must have been making more boost than stock this must have been generating some crazy piston melting heat too.

After watching that video I now have more respect for GM engineers as this motor should have turned into liquid for going this long under high boost wow.
 

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Dont get discouraged superchargers only heats up when ur in boost for looooong period of time.. Otherwise it's ALOT of fun imagine having 100 shot nitrous ALL the time:shocked:

I see in that video they are in the desert so it must of been very hot on that blower i also seen in that video the ctsv boost gauge was pegged all the way to max stock cts gauge only go to maybe about half way i think.. so it must have been making more boost than stock this must have been generating some crazy piston melting heat too.

After watching that video I now have more respect for GM engineers as this motor should have turned into liquid for going this long under high boost wow.
That makes me feel much better. I've never had FI, so I know nothing of their nuances or needs or anything else lol. I was less nervous having my first child :D

With that being said, I'll rescind my comment - the blower is coming heh heh


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Ok, geez guys, r u serious, lets start with the whole weight thing since technically I started it, I said that with 5 people in the car I hit 182 but had to break because of upcoming turn, never said it was top speed, car was still slowly climbing, had I been by myself and reduce the weight by 600 to 800lbs in that same amount of highway before having to break I believe I would have gone faster, maybe 185 or 187, the point of the comment was to challenge the statement that our cars were drag limited at 175, I believe our cars do have a governer (speed limiter) at 175 but with a diablo you can move it up to a max of 190. Don't know what would happen if u hit 190 but I'm sure somebody will and we will all hear about it. Now regarding the scientists on the forumn, are you reading what your writing? Do you really believe that if I take a Bugatti, and make all the panels on it bulletproof increasing the weight by 2000 lbs but keeping the aero dynamics the same that given enough room it will achieve the exact same top speed of a stock Bugatti? If they have the same horsepower, won't the engine have to work much hArder to pull/push the additional 2000lbs which would mean that Rpms would be higher? For example, lets say a stock Bugatti at WOT pushing past 150mph would be in 4th gear at 6200 Rpms, it is my belief that the bullet proof Bugatti would be in 4th gear but at 7800rpms which means that the engine is turning much faster and you have less to give to push the car. Please, don't correct me if I'm wrong, lol


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A pilot could settle this once and for all, lol. They don't have roads or speed limits, and weight does change - ah but so do wind currents and speeds...never mind lol


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Ok, geez guys, r u serious, lets start with the whole weight thing since technically I started it, I said that with 5 people in the car I hit 182 but had to break because of upcoming turn, never said it was top speed, car was still slowly climbing, had I been by myself and reduce the weight by 600 to 800lbs in that same amount of highway before having to break I believe I would have gone faster, maybe 185 or 187, the point of the comment was to challenge the statement that our cars were drag limited at 175, I believe our cars do have a governer (speed limiter) at 175 but with a diablo you can move it up to a max of 190. Don't know what would happen if u hit 190 but I'm sure somebody will and we will all hear about it. Now regarding the scientists on the forumn, are you reading what your writing? Do you really believe that if I take a Bugatti, and make all the panels on it bulletproof increasing the weight by 2000 lbs but keeping the aero dynamics the same that given enough room it will achieve the exact same top speed of a stock Bugatti? If they have the same horsepower, won't the engine have to work much hArder to pull/push the additional 2000lbs which would mean that Rpms would be higher? For example, lets say a stock Bugatti at WOT pushing past 150mph would be in 4th gear at 6200 Rpms, it is my belief that the bullet proof Bugatti would be in 4th gear but at 7800rpms which means that the engine is turning much faster and you have less to give to push the car. Please, don't correct me if I'm wrong, lol


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I actually wasn't talking about your car, honestly didn't even read your post.

Now correct you if your wrong... Ok... Your wrong... Lol... Just kidding... But in honesty unless the weight is severe enough to alter the drag limits or the rolling friction then no the top speed won't be limited by much... It's the same idea as a transport truck can pull 10000lbs at 70 mph.... But if you took the wheels off it couldn't achieve that speed as the rolling friction is way higher, put them back on and add another 10000lbs but one more axle to reduce the friction on the other axles and the same top speed can be had with longer getting there...

As for more revs on the Bugatti, well I'm not sure they would increase, but the engine would be working harder and the car wouldn't accelerate as swiftly. Take your own car... With nobody in it autostick it and accelerate from 60-90 and watch the revs and make note... Do it again with people... I'm pretty sure your revs will be identical (that's gearing) but the time it takes to do it will increase... ;) If it is more its due to slippage in the torque converter which I think you'll find won't be there at higher speeds when the converter is locked.

Weight does have a factor in top speed yes, but not as much as you might think. Especially in relation to a vehicle, its not as much top speed it changes but how long it takes to get there.

Oh... And I'm not a scientist... Trust me... Lol.

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You sir. Are a boss. Loved the video and please keep them coming!!!
 

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Wow. This thread went from a fun post to drag limits, to Newtons law of Physics, to a Bugatti with up-armour. I'll appreciate the video for what it is: We're all damn jealous you have roads that you can do 190 on.
 

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This thread was put up way before I was a member here. That video was awesome, the pissing contest that followed was worth the price of admission.

One hand on the wheel at 190, that guy is nuts!
 

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Can't believe I missed this thread so long ago, but......Yeah, no.

Call me a chicken, but the fastest I've gone (in the last 5 years) is about 250 ish (kph). Just once. I may muster a bit more courage to try to bury the needle on say- a purpose-built track... if there is a long enough straight line.

I'm just deathly afraid of a tire blowout at those speeds. And even at 250 it sure puckers the ole' sphincter at that!

And here this guy in the op's video is one-handing the wheel with a go pro in the other? Man I love a good spirited drive just as much as the next guy, especially in my younger years. Now at 47, watching those videos sends shivers down my spine.

If you're gonna drop the hammer, at least keep both eyes on the road and both hands on the wheel.
 
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