What's the top speed on your car? - Page 3

elma22 · 07-24-2001, 03:57 AM

Guys, Guys , guys
How long ahs it been since you guys took physics? In reply to Jimberg, gravity puls every object down at the same speed, NO EXEPTIONS!!!!!!!! Secondly mass has so much to do with top speed, it is not even funny. Example: a 250 hp engine can propel a 3000lb car to a speed of lets say 140miles. Now the same 250hp engine will propel a 3500 lb car to only 135miles. My rig is capable of 90 miles per hour top speed when loaded with 10 000 pounds. When I got 30 000 lb on the back of my trailer, my top speed is only 80 miles. Aerodynamics along with wieght are very important when dealing with top speed. You will never run as fast with a 50lb bag on your back as you would without it. Porche is fast because it is relatively light, but most of all it has very low wind resistance. So pull up those old physics books and review the formulas. Horsepower is also calculated bases on the vehicle weight and the time it takes to travel a certain distance. Hope I put your minds at rest.

jimberg · 07-24-2001, 11:16 AM

Quote:

Originally posted by elma22:
In reply to Jimberg, gravity puls every object down at the same speed, NO EXEPTIONS!!!!!!!!

Everything falls at the same rate of acceleration (approximately 10 meters per second per second). Objects will, however, reach a terminal velocity because of drag. If you add mass to the object without altering it's aerodynamic properties, its terminal velocity will rise because your creating more force.

[quote]
Secondly mass has so much to do with top speed, it is not even funny.

We just proved it doesn't with the formula Force = Mass x Acceleration.

If the amount of force the engine puts out remains constant and only the mass of the car changes, you can see that only acceleration will go up or down to make the formula work.

Quote:

My rig is capable of 90 miles per hour top speed when loaded with 10 000 pounds. When I got 30 000 lb on the back of my trailer, my top speed is only 80 miles.

This is more because of the friction caused by the load on your wheel bearings, axles, and such. That frictional constant is simply multiplied by the velocity of your vehicle. Aerodynamic drag is multiplied by square of your velocity.

So now I guess we can say that mass plays a very small part of top speed.

With a 300% increase in the payload of your trailer you are claiming an 11% drop in top speed. With a 15% increase in the weight of your car, you're claiming a 3.6% drop in top speed. This doesn't seem to add up.

------------------
351W 89 Mustang GT Convertible

silver_pilate · 07-24-2001, 12:08 PM

MiracleMax,

Good thought. It's been a while since I've had time to play around with physics, but I believe the rule states something like as you approach the speed of light, mass increases exponentially. Good point.

That being the case, in order to accelerate a larger mass, you need a larger force. Such that to reach 1/2 the speed of light, it would take more fuel than there is matter in the universe.

I'm a little rusty, so jump in and tell me where I'm wrong.

--nathan

------------------
--silver_pilate

'91 GT, Built 306, Wolverine 1087 cam, ported Windsor Jr. Irons, and all the goodies...click the link to the left to see a full list of my mods...

Tried and True 302 Being Built to Outrun You! heh heh heh...
--Texas Panhandle--
Check out my site

silver_pilate · 07-24-2001, 12:11 PM

Oh...I just read your next post, MiracleMax. That's what I was thinking.

--nathan

------------------
--silver_pilate

'91 GT, Built 306, Wolverine 1087 cam, ported Windsor Jr. Irons, and all the goodies...click the link to the left to see a full list of my mods...

Tried and True 302 Being Built to Outrun You! heh heh heh...
--Texas Panhandle--
Check out my site

K.C. 5.0 · 07-24-2001, 02:33 PM

Thanx, for all the responses. The reason for the question is on the top speed analyzer it says my car is capable of 168 at 6000rpm's.
I installing a stage 2 NOS kit and was wondering how the 150 shot was going to effect my top speed.
From what I've been reading, Are you guys saying that you could top out your gear given enough straight away? I always thought HP came into play. I didn't think certain cars could reach thier gears top speed because they didn't have the power to.

------------------
95gt 80k, MSD 6AL, MSD coil, pulleys, fpr, cold air kit, off road h-pipe, flowmasters, 3.73, fluidampener, 9mm wires, mega bite jr lowers, kennybrown subframe connectors, edelbrock performer intake, 70mm TB, Aluminum Driveshaft, Tri-Ax shifter.

82 GT · 07-24-2001, 03:03 PM

Like I said before, How many people have the skill or balls to drive as fast as their car is capable?
Who cares if your car is able to reach 180mph if you are to scared to drive that fast? Just like HP, it's no good if you can't use it!

------------------
'82 GT 351W C-4,BBK headers,Carter 625 carb,Comp.Cam,Flowmaster exhaust.
1988 GT...T-5,bone stock

elma22 · 07-24-2001, 06:24 PM

Objects will, however, reach a terminal velocity because of drag. If you add mass to the object without altering it's aerodynamic properties, its terminal velocity will rise because your creating more force.

Jimberg, objects falling down can only decrease in velocity, not increase. As you said 10m per second drop is the maximum gravitational pull, which means that objects can only decelerate based on their aerodynamical shape. Regarding my truck speed, every load is distributed over the area differently, putting more weight on the tractor wheels creating more drag. But lets not forget that mass is very important in determining top speed. Every racer works with the weight of their car to determine how much horsepower his engine needs to produce to reach a certain speed. As long as we live on earth, mass will be important. Now once we conquer space, that will be an other question.
Salud to you all.

jimberg · 07-24-2001, 07:35 PM

Quote:

Originally posted by elma22:
Jimberg, objects falling down can only decrease in velocity, not increase. As you said 10m per second drop is the maximum gravitational pull, which means that objects can only decelerate based on their aerodynamical shape.[/B]

The acceleration of gravity is 10m per second per second (not a typo or 10m/s^2). This means that for every second an object falls 10m per second will be added to its velocity. Without air, this would mean that the object is going faster and faster as it falls. With air, though, the force of air resistance will build which in turn reduces the acceleration of gravity until the point that acceleration is zero. The velocity that the object was able to obtain will be the terminal velocity. If you add mass to the object, force increases since we know that acceleration of gravity is a constant. Since the force of the falling object is greater, the amount of air resistance that builds must also be greater for the object to stop accelerating. This occurs at a higher velocity.

------------------
351W 89 Mustang GT Convertible

Unit 5302 · 07-24-2001, 07:57 PM

Racers do not work with the weight of their cars to get top speed. They try to drop weight to obtain maximum accleration.

The weight of a car will not affect it's top speed. Perhaps your rig, since the inconsistancies in the road as it rises and falls and the inability for the truck to accelerate with any zeal at that kind of speed makes it impossible to reach a top speed as though you were unladen. Also, adding 30,000lbs to the load adds friction to the 18 wheels your running. Commercial trucks already have significantly higher contact patches than cars, do to the need for extra loadbearing capacity. Making every one of those tires squat, even the slightest bit creates more scrub and friction. That could reduce your speed a little.

Put solid tires on your truck, and take it to a perfectly smooth road, and it wouldn't care about the 30,000 lbs very much.

We currently have the technology to accelerate us to 97% of the speed of light. It's quite simple. It uses a nuclear fisson reactor. Creates a nuclear split, and forces the waste out the back. Unfortunately, the compartment would have to be heavily shielded, and about 2 miles away from the reactor.

Dark_5.0 · 07-24-2001, 08:43 PM

If you are saying that weight does not effect the top speed of a car then. You should be able to take your theory to the extremes and it would still hold true.

Once I overloaded the back of the work truck with cement a (96 F-350 1 ton with a 460) the truck would barely move and when it did get going it would not exceed 65 MPH. The cement did not affect the aerodynamics so was it not the weight that slowed the trucks top speed.

If weight is not a factor then why do cars and trucks have a tow rating. According to your theory if you can get the load to move then you can take it all the way up to your vehicles top speed taking the wind drag of the trailor into account of course.

So you are saying that if a car is topped out at 150 MPH and all of the sudden you throw an extra 2000 lbs of weight in the car that it will slow down but will eventually regain its speed of 150 MPH.

If you are saying that weight does not effect top speed but does effect acceleration
then (Force = Mass * Acceleration) it appears to me that if I could effect the acceleration of a car with weight then I would also effect the force or speed since force is a buy product of mass times acceleration....

[This message has been edited by 5.0 HO (edited 07-24-2001).]

BilLster · 07-24-2001, 10:29 PM

sorry guys your thinking of a vacum again when i weigh myself with my paracute i way the same as when i pull the cord but i slow dramaticly at the same weight.

it has to do with drag and serface area amassingly temperature has alot to do with top speed of a vehicle. drag is decreased when the temp goes up but engine power tends to go down.

------------------
89 with 395 single stage n2o .garret t3. 373's Suspention worked out finnaly . need cage .

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07-24-2001, 03:57 AM	#41
elma22 Registered Member Join Date: Jul 2001 Location: Montreal Posts: 45	Guys, Guys , guys How long ahs it been since you guys took physics? In reply to Jimberg, gravity puls every object down at the same speed, NO EXEPTIONS!!!!!!!! Secondly mass has so much to do with top speed, it is not even funny. Example: a 250 hp engine can propel a 3000lb car to a speed of lets say 140miles. Now the same 250hp engine will propel a 3500 lb car to only 135miles. My rig is capable of 90 miles per hour top speed when loaded with 10 000 pounds. When I got 30 000 lb on the back of my trailer, my top speed is only 80 miles. Aerodynamics along with wieght are very important when dealing with top speed. You will never run as fast with a 50lb bag on your back as you would without it. Porche is fast because it is relatively light, but most of all it has very low wind resistance. So pull up those old physics books and review the formulas. Horsepower is also calculated bases on the vehicle weight and the time it takes to travel a certain distance. Hope I put your minds at rest.

07-24-2001, 12:08 PM	#43
silver_pilate DURKA DURKA!! Join Date: Sep 1997 Location: Lubbock, TX...(TX panhandle) Posts: 1,418	MiracleMax, Good thought. It's been a while since I've had time to play around with physics, but I believe the rule states something like as you approach the speed of light, mass increases exponentially. Good point. That being the case, in order to accelerate a larger mass, you need a larger force. Such that to reach 1/2 the speed of light, it would take more fuel than there is matter in the universe. I'm a little rusty, so jump in and tell me where I'm wrong. --nathan ------------------ --silver_pilate '91 GT, Built 306, Wolverine 1087 cam, ported Windsor Jr. Irons, and all the goodies...click the link to the left to see a full list of my mods... Tried and True 302 Being Built to Outrun You! heh heh heh... --Texas Panhandle-- Check out my site

07-24-2001, 12:11 PM	#44
silver_pilate DURKA DURKA!! Join Date: Sep 1997 Location: Lubbock, TX...(TX panhandle) Posts: 1,418	Oh...I just read your next post, MiracleMax. That's what I was thinking. --nathan ------------------ --silver_pilate '91 GT, Built 306, Wolverine 1087 cam, ported Windsor Jr. Irons, and all the goodies...click the link to the left to see a full list of my mods... Tried and True 302 Being Built to Outrun You! heh heh heh... --Texas Panhandle-- Check out my site

07-24-2001, 02:33 PM	#45
K.C. 5.0 Registered Member Join Date: Jun 2001 Location: KC,Mo,US Posts: 70	Thanx, for all the responses. The reason for the question is on the top speed analyzer it says my car is capable of 168 at 6000rpm's. I installing a stage 2 NOS kit and was wondering how the 150 shot was going to effect my top speed. From what I've been reading, Are you guys saying that you could top out your gear given enough straight away? I always thought HP came into play. I didn't think certain cars could reach thier gears top speed because they didn't have the power to. ------------------ 95gt 80k, MSD 6AL, MSD coil, pulleys, fpr, cold air kit, off road h-pipe, flowmasters, 3.73, fluidampener, 9mm wires, mega bite jr lowers, kennybrown subframe connectors, edelbrock performer intake, 70mm TB, Aluminum Driveshaft, Tri-Ax shifter.

07-24-2001, 03:03 PM	#46
82 GT Import Slayer Join Date: May 1999 Posts: 2,241	Like I said before, How many people have the skill or balls to drive as fast as their car is capable? Who cares if your car is able to reach 180mph if you are to scared to drive that fast? Just like HP, it's no good if you can't use it! ------------------ '82 GT 351W C-4,BBK headers,Carter 625 carb,Comp.Cam,Flowmaster exhaust. 1988 GT...T-5,bone stock

07-24-2001, 06:24 PM	#47
elma22 Registered Member Join Date: Jul 2001 Location: Montreal Posts: 45	Objects will, however, reach a terminal velocity because of drag. If you add mass to the object without altering it's aerodynamic properties, its terminal velocity will rise because your creating more force. Jimberg, objects falling down can only decrease in velocity, not increase. As you said 10m per second drop is the maximum gravitational pull, which means that objects can only decelerate based on their aerodynamical shape. Regarding my truck speed, every load is distributed over the area differently, putting more weight on the tractor wheels creating more drag. But lets not forget that mass is very important in determining top speed. Every racer works with the weight of their car to determine how much horsepower his engine needs to produce to reach a certain speed. As long as we live on earth, mass will be important. Now once we conquer space, that will be an other question. Salud to you all.

07-24-2001, 07:57 PM	#49
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	Racers do not work with the weight of their cars to get top speed. They try to drop weight to obtain maximum accleration. The weight of a car will not affect it's top speed. Perhaps your rig, since the inconsistancies in the road as it rises and falls and the inability for the truck to accelerate with any zeal at that kind of speed makes it impossible to reach a top speed as though you were unladen. Also, adding 30,000lbs to the load adds friction to the 18 wheels your running. Commercial trucks already have significantly higher contact patches than cars, do to the need for extra loadbearing capacity. Making every one of those tires squat, even the slightest bit creates more scrub and friction. That could reduce your speed a little. Put solid tires on your truck, and take it to a perfectly smooth road, and it wouldn't care about the 30,000 lbs very much. We currently have the technology to accelerate us to 97% of the speed of light. It's quite simple. It uses a nuclear fisson reactor. Creates a nuclear split, and forces the waste out the back. Unfortunately, the compartment would have to be heavily shielded, and about 2 miles away from the reactor.

07-24-2001, 08:43 PM	#50
Dark_5.0 Registered Member Join Date: Apr 2001 Location: Staging lane Posts: 4,337	If you are saying that weight does not effect the top speed of a car then. You should be able to take your theory to the extremes and it would still hold true. Once I overloaded the back of the work truck with cement a (96 F-350 1 ton with a 460) the truck would barely move and when it did get going it would not exceed 65 MPH. The cement did not affect the aerodynamics so was it not the weight that slowed the trucks top speed. If weight is not a factor then why do cars and trucks have a tow rating. According to your theory if you can get the load to move then you can take it all the way up to your vehicles top speed taking the wind drag of the trailor into account of course. So you are saying that if a car is topped out at 150 MPH and all of the sudden you throw an extra 2000 lbs of weight in the car that it will slow down but will eventually regain its speed of 150 MPH. If you are saying that weight does not effect top speed but does effect acceleration then (Force = Mass * Acceleration) it appears to me that if I could effect the acceleration of a car with weight then I would also effect the force or speed since force is a buy product of mass times acceleration.... [This message has been edited by 5.0 HO (edited 07-24-2001).]

07-24-2001, 10:29 PM	#51
BilLster Registered Member Join Date: Oct 2000 Location: Ontario canada Posts: 446	sorry guys your thinking of a vacum again when i weigh myself with my paracute i way the same as when i pull the cord but i slow dramaticly at the same weight. it has to do with drag and serface area amassingly temperature has alot to do with top speed of a vehicle. drag is decreased when the temp goes up but engine power tends to go down. ------------------ 89 with 395 single stage n2o .garret t3. 373's Suspention worked out finnaly . need cage .