JuicedS2K

First one.

Do you guys think our cars will be faster with me removing the soft top cause it sheds around 70lbs, so i hear anyway, or will it be slower with no top because of the drag.

Second one.

Say you have 2 identical cars, everything is exactly the same besides the torque. Take one car with 300 ft lbs of torque and another one with 130 ft lbs of torque. At this point they both weigh the same.

If you shed 500 pounds from each, isn't the car with less torque going to feel a greater advantage then the car with a lot of torque. Since the 130 torque car has so little, wont that drastic weight decrease make a bigger diff in a car with such little torque then taking it away from a car with 300 ft lbs of torque??


lol sorry, i hope you guys understand what i am asking, i always wondered this stupid stuff.

samsam5886

A weight reduction of the same amount to both of those cars should result in equal results overall. But in lower RPMs for daily driving, it should benefit our S2K more. Don't worry too much about our car's lack of torque. It's horsepower that tells how fast a car accelerates

And there will be extra drag if you drive without the top. But the drag should hurt your top speed more than your acceleration, so the drag won't make that much of a difference. You could get a hardtop too.

fastD

Sorry but it's torque that determines the rate of acceleration...

s2kvince

Sorry, it's not.

Power is the rate at which work is done. A car with 240hp but more torque may be faster, but it's only because it makes more power across the RPM range.

Riviera

Torque - pulling force
Power - rate of work done

If you are saying, torque determines acceleration, please do explain why our S accelerates faster than say a truck with a mountain of torque.

But in saying that, acceleration can not be achieved by a single element. You have to take into account every single factors such as aero, for example.

ahrmike

Sup Directported!

I think I can answer all of your questions.

First: FAST and QUICK are different: Aerodynamics will only affect you when you are going fast (High speeds). The weight reduction will help you when you are going quick(high acceleration@low(er) speeds).

basically, 0-60mph(+/- mphs for how bad/good our car aerodynamics are) for weight reduced car = faster, but top speed (fast) for convertible topped car will be higher.

There will come a speed - if you give me the CdA of the car with topless, top up, power i can tell you - where from say 60-100 the aerodynamics will affect you, more then the weight of the car, so it may be quicker from a certain speed to another speed to have the top up, but for almost any legal speeds the topless car will hit that speed faster.

-In other words, TOP SPEED is affected only by: Power to the wheels and Aerodynamic+frictional Drag.

-Acceleration is affected by both power to wheels, aero, weight, friction, and aero drag is negligible @ low speeds, but become a larger part of the drag as you gain velocity.

Part two depends on multiple things. Gearing, weight, and horsepower curve. IF you assume that the cars are identical in weight, then this would most likely mean that the car with more torque is actually faster anyway- this is because it is based on the area under the horsepower curve, the horsepower @ a certain RPM is a function of TORQUE, which means with more torque, you have more hp under the rpm curve used.

sidenote: Gearing will change which part of the powerband the car is: If you have a short geared car, this may be able to make up for peaky torque curves. You basically have to look only at the RPMband where you will be in during the race.

If say the car with more torque is the heavier one, then yes, 500 lbs lost on the lighter car = bigger percentage lost, which means that it will affect it more - that is, if they were running DEAD EVEN before the weight reduction, the lighter car will be faster. This is due to the HORSEPOWER curve.

if the smaller car is making enough power to keep up with the heavier, torquey car, that means the (used part of RPM band) HP/lb for the two cars are the same - if the weight lost is the same, this makes a bigger change for the lighter car - which means a win for the lighter car.

ace123

My guess is that below 60mph it will pull faster and above 100mph it will pull slower. Somewhere in between 60-100 it would be even.

Power divided by weight is what you're really after, not torque divided by weight. This can be confusing, because torque times effective gearing is power, so more torque also implies more power.

If the cars have the same gearing (transmissions, differentials, wheel sizes and such), power = torque * RPM * some constant due to gearing and such. This makes it so the same trends that work with power will be true with torque also.

So for this example, comparing two of the same car to one another, weight reduction improves the power to weight ratio (Power divided by Weight) will be increased more on the higher torque than the low torque car ONLY BECAUSE it is also the higher power car. So really you have a high HP car and a low HP car with the same weight. If you decrease the weight of both cars, the high power car will benefit more from the reduction because it has more power, and the power to weight ratio is amplified by weight reduction.

Elistan

1) 240hp, 2800lbs S2000 equals 11.66 lbs per hp. 240hp, 2730lbs S2000 equals 11.375 lbs per hp, same as a 246 hp, 2800 lbs S2000. That doesn't take into account cornering performance, but I know for a fact that going with my top down reduces my top speed from 129 mph at Texas World Speedway to about 115 mph. Six horsepower is NOT enough to make up for that. You're best off keeping the top on, IMO.

2) Everything else the same? Same peak horsepower? Same relative torque curve? Gearing such that sift points are at the same mph? If so, the two cars will have the EXACT SAME WHEEL TORQUE which is all that matters, and will therefore be effected in the exact same way by the 500 lbs weight reductions.

CKit

You're completely wrong..... it's spelled theories.

hariku821

"Horsepower sells cars, torque wins races." Carroll shelby


http://www.moddedmustangs.com/forums/gener...wins-races.html


While i may be bias against mustangs, they should know more about torque since they actually have some ... They do refer to us as ricers though