nascar trucks?

[ccrider]

i can across this picture on the internet and i figure that the nascar truck teams must do more aerodynamic testing than anyone. i think that they do not use a aerocap design because i would imagine that the truck sponsors want the trucks to resemble a production truck. so i am wondering if the same results as a aero cap can be achieved with a torrnea cover and a rear spoiler? does the air going over the truck pass over top of cab and then the rear spoiler act as if there is a aero cap on the truck?

also i am wondering why they went with a air dam instead of a belly pan? i can see that the truck is lowered and the air dam is really close to the road with side skirts

i know their concern is not fuel economy but the aerodynamics must apply to fuel economy





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[Christ]

Well, they do and don't.

They're more interested in downforce than anything else, which is nice for when you're going 200 MPH around a corner, ya know?

I'll try to find it again, there was a webpost somewhere (that I probably didn't save) which detailed the Cd and A of the newest NASCAR vehicles, including the trucks. IIRC, they were about average for our purposes, but can make 1,000's of lbs of downforce at speed.

[ChazInMT]

Yeah, Downforce...I say it's over rated. But 4 out of 5 NASCAR crew chiefs recommend it for their drivers.

[jamesqf]

Hey, that's cheating! No fair passing by flying over the car ahead.

[Old Tele man]

...Motorsport News headline: "Leap Frogging driving technique not quite perfected at Daytona."

[Frank Lee]

That air dam is too low for the street but I'd imagine it's so low that a belly pan would be largely redundant i.e. a pan would do little good.

[Jethro]

I'm sure, knowing Nascar that there are restrictions as to what can be done to the underbody as well.

[micondie]

Both the design of the air dam and the rear spoiler are specified by NASCAR

[RobertSmalls]

Disappointingly, a Google Image Search for "salt flats pickup truck" doesn't yield anything more than airdams and tonneau covers.



^ Desperately needs rear wheel skirts and a teardrop-shaped bed.

[aerohead]

Originally Posted by ccrider

i can across this picture on the internet and i figure that the nascar truck teams must do more aerodynamic testing than anyone. i think that they do not use a aerocap design because i would imagine that the truck sponsors want the trucks to resemble a production truck. so i am wondering if the same results as a aero cap can be achieved with a torrnea cover and a rear spoiler? does the air going over the truck pass over top of cab and then the rear spoiler act as if there is a aero cap on the truck?

also i am wondering why they went with a air dam instead of a belly pan? i can see that the truck is lowered and the air dam is really close to the road with side skirts

i know their concern is not fuel economy but the aerodynamics must apply to fuel economy





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cc, the teams spend an enormous amount in wind tunnel time to evaluate drag vs downforce.
NASCAR probably forbids aeroshells as they would not match 'Templates' used by officials to 'pass' vehicles.
A carefully designed cab-wing/sail panel,along with a 1/2-tonneau can approach the drag reduction of an aeroshell.
The locked-vortex behind the cab,and above the tonneau on the NASCAR truck creates a 'phantom' shell with outer flow skipping over.
The rear spoiler is only for downforce.
The airdam and skirts form a duct which allows the low base pressure of the wake to communicate underneath for downforce.More drag.
Hucho uses the term 'minimum' for airdams.Too much of a good thing and your drag begins to go back up.And the drag increase can be remarkable!