Does lowering drag improve Acceleration?

[Phase]

So obviously lower drag helps hit top speeds, but how much effect does drag have on 0-60 times?

any papers or tests people can share or personal experience? obviously at 60mph drag isn't that strong, but I'd be curious to see if it can improve times by even a second or two.

Like someone lowers their cd .30 car down to .25 and their 0-60 time goes from 9.5 seconds to 7.8 seconds or something...

[oil pan 4]

I don't think you will see anything that dramatic till you are looking at 0 to 120mph.
From about 0 to 40mph aerodynamics are nearly irrelevant.

[freebeard]

Weight transfer (rear wheel drive) trumps drag.
https://www.hotrod.com/uploads/sites...er-Vintage.jpg

[Ecky]

Originally Posted by freebeard

Weight transfer (rear wheel drive) trumps drag.
https://www.hotrod.com/uploads/sites...er-Vintage.jpg

Assuming you have enough power to break the rear wheels free to begin with. I can barely do that dumping the clutch in 1st.

[Phase]

I was just wondering because my car is a hybrid and has a lot of torque. 0-40 it’s fast, I even beat a charger in a race at a stop light. But that 40-60 is such a drag and the speed accelerating tank drops. Obviously that’s part of it being a 4 cylinder low horsepower engine. Was just wondering if I’d see any change by lowering drag, since I know you do experience a little drag between 40-60 but it’s smaller

[Ecky]

Originally Posted by Phase

I was just wondering because my car is a hybrid and has a lot of torque. 0-40 it’s fast, I even beat a charger in a race at a stop light. But that 40-60 is such a drag and the speed accelerating tank drops. Obviously that’s part of it being a 4 cylinder low horsepower engine. Was just wondering if I’d see any change by lowering drag, since I know you do experience a little drag between 40-60 but it’s smaller

I expect what you're just seeing is a combination of gearing an the electric motor's torque curve. Typically they look something like this:



We're accustomed to gasoline engines producing more and more power as they rev, and electric motors do just the opposite (to a point).

[Piotrsko]

Not sure beating a charger is that big a challenge anymore.

[Piwoslaw]

If you improve aero by removing heavy things, like a roof rack, side mirrors, ricer spoiler, etc., then...

[The Toecutter]

There is no short answer to your question. It's going to depend on all of the vehicle's parameters: mass, original drag coefficient, engine's power/torque curve, gear ratios, tire size, driveline efficiency, ect.

But lets take an extreme example, a 1st gen VW Beetle with only 25 horsepower. It could just barely reach 60 mph. Cutting its drag by half would shave seconds off its 0-60 mph time, but it also had a very slow 0-60 mph time to begin with.

In the case of your Ionic, even if you cut your drag coefficient in half, it probably wouldn't make more than a 0.1-0.2 second difference in your overall 0-60 mph acceleration. The reason being, that at full throttle you will have a lot of surplus torque available to accelerate the car for the entire speed range, no matter what the drag is(assuming it is a figure appropriate for cars, and you're not pushing, say, a 120-story skyscraper through the air). Acceleration from 60 mph to top speed, however, drag reduction will make a more noticeable difference. In fact, the higher the speed you are travelling, the more of a difference in acceleration that drag reduction makes.

Consider Newton's law: (Net Force) = (Mass) X (Acceleration)

After ALL forces are overcome to keep the vehicle at speed, it is the surplus force left available that accelerates the car. While accelerating full throttle, by the time you hit 60 mph, the surplus force available to accelerate the car is still copious. Cutting drag in half would not increase it by a significant amount, and at the lower end of the range towards 0 mph, it just doesn't matter.

If you know how to do calculate integrals, you can calculate how much of an impact cutting drag by a certain amount will have in your specific case. It is a long and involved calculation. On a now defunct computer, I made some spreadsheets for just such a task, but I don't currently have them available and need to pull them off the hard drive.

Originally Posted by Phase

So obviously lower drag helps hit top speeds, but how much effect does drag have on 0-60 times?

any papers or tests people can share or personal experience? obviously at 60mph drag isn't that strong, but I'd be curious to see if it can improve times by even a second or two.

Like someone lowers their cd .30 car down to .25 and their 0-60 time goes from 9.5 seconds to 7.8 seconds or something...

[Blacktree]

Originally Posted by Phase

I was just wondering because my car is a hybrid and has a lot of torque. 0-40 it’s fast, I even beat a charger in a race at a stop light. But that 40-60 is such a drag and the speed accelerating tank drops.

That's probably more a function of drivetrain design than anything else. Just be happy you have decent acceleration in the 0-40 mph range. Because many cars don't.