Real World Aerodynamics

[Chris Hill]

Just curious how much aerodynamics help/hurt in drag racing?

Great example is A/SA class final between Larry Hill and Leonard Mattingly.

Hill has 70 cuda and Mattingly has 2000 Firebird. Both cars at same weight, so it's a great comparison.

Hill is 0.8 mph faster in 1/8 ,but Mattingly is 0.7 mph faster in 1/4. Mattingly increases 1.5 mph last half of track. I think that's a lot to make up last 1/2 of the track.

Hill 10.07 at 129.7 to Mattingly's 10.08 at 130.4 mph.

My gut says Hill makes slightly more hp by 1/8 mph, but the aerodynamics of newer and smaller car takes over after 100 mph.

Any SS guys have experience going from old school car to new jellybean car with same combo and weight?

Estimated coefficent of drag for 2000 camero is 0.34
Estimated coefficent of drag for 1979 mustang is 0.46

[Kevin Panzino]

The Zaskowski's have a great video of father and son side by side heads up for class. The camera is in the camaro looking over at the Chevy II. The cars are extremely close together with the deuce actually gaining a tad on each gear change. Then around 800 ft ish, you watch the camaro begin to get ahead. I think its a great example of exactly what you are talking about. (Plus its an incredibly cool video anyway!!!!)

Kevin

[SSDiv6]

Chris,
I have posted on this subject in the past.

In addition to poor frontal area Cd, after the launch until the 1/8, most cars are dealing with the ground effects. Due to poor Cd, some cars are more susceptible to ground effects than others.

After the 1/8, as speed increases, if your vehicle has a good Cd, the ground effects start to cancel and aerodynamics plays a major role to stabilize the vehicle and reducing drag while accelerating.

It is one of the reasons why you may have seen some cars porpoising down the track. The cause is ground effects not canceling while the car is accelerating due to both, poor aerodynamics and also the suspension not being properly adjusted. Porpoising also increases drag on the vehicle.

[junior barns]

Hi Chris. Back when top stock first came I remember Mat Morgan showing wind tunnel numbers between the new firebird and a 69 Camaro and a 69 corvette. His conclusion ( the best I remember) were that as long as no big head wind, the cars would not notice any difference on drag until they approached 130 mph. At that time he was driving a 69 Camaro. I'm sure he got the wind tunnel numbers from the manufacture . He also had numbers for the 69 mustang for the comparison. Wish I would have saved it!!

[Greenlight]

Here are some drag coefficient values:

http://www.mayfco.com/tbls.htm

[Myron Piatek]

A Dodge Viper has a worse Cd than a Dodge p/u truck?!?

[nickh]

Always been interested in aero myself, my 73 nova bracket car must be in the .60's LOL

[Randall Klein]

FWIW
When Warren Johnson was racing the Cutlass he wrote an artice in ND about aero, if I recall correctly he said it didn't make much difference until tje very end at 200mph

Of course he was representing Oldsmobile (and the Cutlass)....those Cutlass's were very smooth

[Myron Piatek]

Originally Posted by Randall Klein

FWIW
When Warren Johnson was racing the Cutlass he wrote an artice in ND about aero, if I recall correctly he said it didn't make much difference until tje very end at 200mph

Of course he was representing Oldsmobile (and the Cutlass)....those Cutlass's were very smooth

A few paragraphs down, Warren talks about how inferior the Firebird was compared to the Cutless it replaced......by 1.5 MPH!

http://www.hotrod.com/articles/drag-...hnson-profile/

[nickh]

WJ also said a while back that the forward facing hoodscoops took away about 60 hp with the drag it created.