Does lowering drag improve Acceleration?
 

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...

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.

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

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:

https://www.researchgate.net/profile...l-motor-12.png

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

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

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

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.

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.

So lower drag pretty much Would help me more when I’m passing slower cars on desert roads?

Sometimes the speed limit is 65/70 and one lane and you gotta stomp it to pass 3 cars following behind a slow Rv going 45/50 mph

I’ve hit 110 mph before for a second when having to pass a slow train of cars in the middle of nowhere in Arizona/Utah

The nice thing about low drag is that at very high speeds, acceleration improves greatly, and if you have appropriate gearing for it, so too does top speed.

A typical musclecar like a base model V6 Dodge Charger needs somewhere around 300 horsepower to hold 160 mph. The Opel Eco Speedster could reach the same 160 mph speed on only 112 horsepower. From 120+ mph, their acceleration is probably comparable. The Eco Speedster's low drag also allowed it 94 mpg US combined, with 113 mpg US on the highway.

If you want to improve acceleration at the low end, you need either more power, or less mass. The latter has the benefit of improving fuel efficiency, most especially during acceleration.

People usually think fuel efficiency and performance are mutually exclusive, but it is the opposite that is true. The problem is our cars are designed totally backwards, to make rich people even more richer, at everyone else's expense, as opposed to getting the best performance and operating cost out of the vehicle.

If I ran Stellantis, the Dodge Charger Hellcat would be a streamliner of a land yacht that got close to 50 mpg highway, and was geared for 270 mph top end, using the same 707 horsepower V8 and there would be an EV version competing with the Tesla Model S PLAID.

0-60
 

https://www.omnicalculator.com/everyday-life/0-60I'm in the ' it's conditional' camp.
With graph paper and some starting assumptions, you could calculate your average velocity per each second of acceleration, and take a look at your 'residence time per velocity regime, up to 60-mph.
It requires differential equations for accurate values, as rolling resistance, aero drag, available power, torque, gearing, friction due to transmitted power, tribological losses, polar moments of inertia, engine accessory losses, ................ are all conspiring against the car in real time.
You might find some calculators online.
My gut feeling is that 0-60 is a 'drag race' and it's all about power-to-weight ( mass ).
High speed passing would be another kettle of fish, and aero would be more 'visible'. Bonneville and Homeland Security demonstrated that for me.
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I'll try for a link

That is actually an interesting question, assuming you are in top gear at reasonably low revs, (say 1000-2000rpm) the engine (assuming petrol and naturally aspirated) will have very little power even at full throttle.

Say, for example, at 50mph you may need 15hp, and the engine is capable of producing 30hp at that rpm. If you cut drag by 33%, you have reduced drag from 15hp to 10hp. But you have also gone from having 15hp to accelerate with to 20hp to accelerate with. Theoretically you accelerate 33% faster.

Doing 0-60, when you are in optimal gear at high revs, the available power/drag ratio is far different, most cars having 100-200hp you wouldn't notice 5hp extra because you have better aero.

Aero so bad it matters:
https://www.youtube.com/watch?v=1X35-bGWpEY

0.74 Cd with wing, compared to the stock Corvette being measured as 0.32 in the same wind tunnel.

That means a lot for economy. A stock Corvette of that style with an engine re-tune for leaner burning can get 40 MPG at 70 mph with the tuning for efficiency also accompanying a power increase:

https://www.youtube.com/watch?v=vNIZ25eBMco

A pushrod V8 is far from the most efficient thing in the world, so do keep that 40 mpg figure and what it can mean for something much more light and slippery in mind.

A Corvette platform could make for a beautifully-performing custom streamliner given its durability and layout, where both performance and fuel economy alike would match the "best" production cars for those categories, and it would probably be reliable too. Parts are relatively easy/inexpensive to source in the U.S. Frontal area, drag coefficient, and weight could all be reduced significantly over a stock Vette, while retaining the original engine, which is a powerful, reliable, highly tunable workhorse.

I do think a V8 2-seater making 60 mpg highway is quite possible... and it would be relatively easy/inexpensive to make it a top performer at the same time. A Panhard CD Peugeot 66C shape laid out over such a platform, and modified with the bare minimum downforce needed for stability(especially attacking low hanging fruit that add lots of downforce but usually minimizes added drag, like ground effects, and while avoiding the use of wings and items that are very drag inducing). The stock Panhard CD Peugeot 66C shape had a Cd of 0.13, but I think somewhere in the upper 0.1X region is doable while having enough downforce not to lose control at 220 mph, which would likely be its capability with stock horsepower, but that engine is tunable to a lot more than that. But because the car itself might be 1,000+ lbs lighter than a stock C5 Vette, its 0-60 mph and 1/4 mile times would still be able to hold their own with modern supercars that can reach near that same top speed. The difference might be a tripling of typical supercar fuel efficiency while also making a supercar that is inexpensive and reliable to operate, that could even match a Prius in highway fuel economy without even having a hybrid powertrain.

Maybe someday I'll get a chance to make a proof of concept of such a thing.

Of course, the Corvette platform, being as sturdy as it is, lends itself well to some off-the-wall engine choices. You could take that Vette apart and find a way to mount a Cummins turbodiesel in the middle of that chassis, then build around it. So many directions that one could go...

Which one? According to duckduckgo.com/?q=Panhard+CD+Peugeot+66C&ia=images The 1964 and 1967 Lemans entries have distinct differences.

Rather than changing the body into something else, I could see sacrificing lateral acceleration and go to tall narrow wheels and tires with as much negative offset as possible to accommodate four wheel skirts.

Freevalve four-cylinder?

The 1967 designed by Deutsch Bonnet. With the full tail, its drag coefficient came out to 0.13. The dual rear fins help it to stay stable on the Mulsanne straight without much need for downforce.

Coupled with the low frontal area, this shape over a Corvette chassis and appropriately scaled for width/wheelbase would have about 1/3 as much aero drag as a stock Corvette. As far as cars of the time period go, the C5 Corvette was already among the most slippery available and got decent highway mpg bone stock, so cutting its drag to 1/3 is going to have a massive impact.

And it is easy to find an engine greatly more efficient than that crappy(at least regarding thermal efficiency) pushrod V8 it came with, but it would still get good economy with its original engine.

Hard to say what the results of that would be. The Corvette's shape, while more slippery than the average car of its period, still had a lot of compromises made for aesthetics. I wonder what kind of Cd would be possible going that route?

If you're going to downside the cylinders and displacement, why not the 3-cylinder freevalve engine used in the Koenigsegg RAW concept? 600 horsepower in only 2L of displacement, but overall thermal efficiency comparable to the anemic Atkinson-cycle engine in a Prius. And its low mass would do a lot to keep the weight down.

That might open the door to such a car weighing significantly under 2,000 lbs in spite of the large footprint of the chassis if you get rid of that stock lump of a pushrod V8, and economy would go up even more with a more efficient engine. The wide track and long wheelbase of the Corvette chassis coupled with such lightness with most of the weight in the center of the chassis would have an unholy cornering potential too, even without the typical downforce aids most racecars use...

Maybe 70+ mpg HWY non-hybrid supercar? That would be really sweet.

Here's why I mentioned four wheel skirts. the Volhart-Sagitta V2 returned 0.217 in a modern wind tunnel.

https://ecomodder.com/forum/member-f...ve12d2-549.jpg

Four passenger instead of two. I'd not be averse to a three-cylinder.

edit: See also: ecomodder.com/forum/543600-post2421.html

When I aeromodded the Aerocivic, it had little effect on the 0 to 60 time, but had a huge effect on the 60 to 100 time.