Daytona Downforce

[histoy]

I was just reading about the 2016 Viper ACR.  The article said that the body and wing design gives the ACR 2,000# of downforce at 177 mph.   I was thinking that the Daytona had around 600# of downforce in the front and considerably less in the rear.  Does anyone remember the correct numbers?   

[odcics2]

The race Daytona had a zero lift front end and you could get some down force with a larger spoiler. (staying within Nascar rules: 6.5" from the ground, no wider than the center of the tread width of the front tires)

The rear wing could give you a few hundred pounds, depending on angle.   


aerowwarriors.com has the graphs showing exact numbers. 

[histoy]

Thanks for the info

[Aero426]

The race Daytona had a zero lift front end and you could get some down force with a larger spoiler. (staying within Nascar rules: 6.5" from the ground, no wider than the center of the tread width of the front tires)

The rear wing could give you a few hundred pounds, depending on angle.   

Which doesn't sound like much until you compare it to the severe lift that the conventional Charger generated.   It turned the car into something that was neutral with a little bit of stick in the back.

[odcics2]

The race Daytona had a zero lift front end and you could get some down force with a larger spoiler. (staying within Nascar rules: 6.5" from the ground, no wider than the center of the tread width of the front tires)

The rear wing could give you a few hundred pounds, depending on angle.   

Which doesn't sound like much until you compare it to the severe lift that the conventional Charger generated.   It turned the car into something that was neutral with a little bit of stick in the back.

Indeed!  The '68 race car had over 1,200 pounds of lift in front!!   The 500 was better.   The Daytona was best!

[Stevearino]

The race Daytona had a zero lift front end and you could get some down force with a larger spoiler. (staying within Nascar rules: 6.5" from the ground, no wider than the center of the tread width of the front tires)

The rear wing could give you a few hundred pounds, depending on angle.   

Which doesn't sound like much until you compare it to the severe lift that the conventional Charger generated.   It turned the car into something that was neutral with a little bit of stick in the back.

Indeed!  The '68 race car had over 1,200 pounds of lift in front!!   The 500 was better.   The Daytona was best!

I have posted this elsewhere on the net but as a reference the current cars generate about 2,000 pounds of overall downforce at speed.  When wind tunnel tested the car that Bobby Allison got airborne and tore up the catch fence at Talladega with had about 600 pounds (300 counts) of lift over all. About 300 pounds per end.  The car was launched into the air when the harmonic balancer  came of the front of the motor bounced off the ground and hit the oil pan. Only about 15 pounds of force.  Gives you some idea about really how brave those old drivers were.

[odcics2]

Keep in mind that the 'old' cars had more ground clearance, both static and dynamic.   One of the reason a car will lift is when the "ground effect" is broken suddenly.   The 'old' cars already had air underneath, so that effect is lessened. 

I like watching the old Darlington races, where a draft of cars would go around, tails hanging out, on bias ply tires!

The top 5-6 all time winners all had huge kahunas.   

[Stevearino]

Keep in mind that the 'old' cars had more ground clearance, both static and dynamic.   One of the reason a car will lift is when the "ground effect" is broken suddenly.   The 'old' cars already had air underneath, so that effect is lessened. 

I like watching the old Darlington races, where a draft of cars would go around, tails hanging out, on bias ply tires!

The top 5-6 all time winners all had huge kahunas.   

I always say and nobody seems to know what I am talking about when they talk about what is missing from stock car racing today. With the radial tire technology  and the great aero you have what appears to be smooth slot car racing. In the old days with the bias ply tires and lack of aero you could see the humanity in the racing as drivers would slide and man handle a car. You could tell there were people out there doing that stuff and it was exciting. You only have to go back to the early 90's to see the difference in the way the cars looked and handled to almost instantly see the difference.

[held1823]

i understand how down force helps with handling, which equates to more speed around an oval. the 2000 pound number is staggering. drag your hand across a table with it just resting on the table, and repeat it while pressing down with your hand. perhaps there is some complicated formula that shows the error of my thinking, but wouldn't more down force require more horsepower?

[dyslexic teddybear]

Keep in mind that the 'old' cars had more ground clearance, both static and dynamic.   One of the reason a car will lift is when the "ground effect" is broken suddenly.   The 'old' cars already had air underneath, so that effect is lessened.  

I like watching the old Darlington races, where a draft of cars would go around, tails hanging out, on bias ply tires!

The top 5-6 all time winners all had huge kahunas.    

I always say and nobody seems to know what I am talking about when they talk about what is missing from stock car racing today. With the radial tire technology  and the great aero you have what appears to be smooth slot car racing. In the old days with the bias ply tires and lack of aero you could see the humanity in the racing as drivers would slide and man handle a car. You could tell there were people out there doing that stuff and it was exciting. You only have to go back to the early 90's to see the difference in the way the cars looked and handled to almost instantly see the difference.

Interesting.......and agree. The boring tracks would be far less boring with less areo.

IIRC........reading a column in StockCarRacing during the changeover to radials....the super speedways got them first, the author recommended getting to the short tracks before it was too late to see drivers "hustle" [term he used=drifting/sliding] a car. Said it was something to see [his opinion] the best still competing, Dale Sr. sliding the car thru the corners.

Wonder how many people still know what "stagger" is?

[held1823]

Wonder how many people still know what "stagger" is?

a picture is worth a thousand words

[odcics2]

Keep in mind that the 'old' cars had more ground clearance, both static and dynamic.   One of the reason a car will lift is when the "ground effect" is broken suddenly.   The 'old' cars already had air underneath, so that effect is lessened. 

I like watching the old Darlington races, where a draft of cars would go around, tails hanging out, on bias ply tires!

The top 5-6 all time winners all had huge kahunas.   

I always say and nobody seems to know what I am talking about when they talk about what is missing from stock car racing today. With the radial tire technology  and the great aero you have what appears to be smooth slot car racing. In the old days with the bias ply tires and lack of aero you could see the humanity in the racing as drivers would slide and man handle a car. You could tell there were people out there doing that stuff and it was exciting. You only have to go back to the early 90's to see the difference in the way the cars looked and handled to almost instantly see the difference.

[Stevearino]

i understand how down force helps with handling, which equates to more speed around an oval. the 2000 pound number is staggering. drag your hand across a table with it just resting on the table, and repeat it while pressing down with your hand. perhaps there is some complicated formula that shows the error of my thinking, but wouldn't more down force require more horsepower?

There is a limit to everything and yes if you have sufficient horsepower you can over come the drag components of a particular feature of the car that creates down force. A wing can give you great downforce with little drag. A flat spoiler has it's limits. There is a point at which the spoiler angle stops creating downforce and  only generates drag. Usually anything greater than 70 degrees you are just creating drag. Pans and splitters also are sensitive  to size , angle and shape. More is not always better. I have seen them add 2 inches in height to the rear spoiler and generate no more downforce at all.

Wonder how many people still know what "stagger" is?

a picture is worth a thousand words

The real beauty of the bias ply and stagger  was that you could man handle an ill handling race car and a savvy crew chief could fix a bad mechanical set up by adjusting the stagger. The result was someone who did not handle early in the race would  many times come charging up through the field later on once they fixed their problems. Now you are pretty much stuck with what you have. Also mechanical grip does not go away when you slow down as does downforce nor does it go away around other cars. A whole generation of drivers and crew chiefs went by the wayside with the radial tire and with it some of the very heart of the sport.

[odcics2]

 

[Mike DC]

I agree.  Modern NASCAR absolutely mystifies me. 


Why switch to radials?  Why switch to fuel injection?  So a solid-axle RWD V8 tube-framed racecar with decals for headlights won't get too far removed from production cars?  It seems like just change for the sake of change.  Like they're trying to remove the worst of the insults people use against the sport.  Maybe next they'll switch to independent rear suspensions. 

The modern cars are glued to the track with downforce & radials so you can't see them do anything.  It's a whole field of bunched-up slot cars at 200mph, staying in perfect formation until "the big one" where half the field goes flying like a kid kicking a pile of matchbox cars.  Where's the RACING for the audience to SEE? 

In NASCAR's defense though, this issue affects all the motorsports.  F1 does the same thing in terms of sticky tires & downforce.

[BROCK]

I blame the self-cancelling blinker on ruining society as a whole.  I blame Bill France on ruining NASCAR.  We can argue what defines this NASCAR ruining over & over without getting anywhere.  Aerodynamics & tires did not keep up with the advent of faster tracks.  Once those 2 struggles were overcome, restrictor plates were introduced.  Another beginning of ruination. I quit watching NASCAR in the late 70s & see much less reason to care anymore since all the bodies are equal now.  Sorry, I root for innovation & not for drivers.

[odcics2]

The mechanical and aero roll centers of the car were brought closer together with the Daytona Package.

Simply, they handled better!