Aeromodding a dragster

[trikkonceptz]

Here is an interesting question ... Can a dragster like the one pictured below benefit from mods ... Taking this car specifically;

-Would front and rear removeable wheel skirts help ? (If regulations allow)
-Slight Kammback to optimise the drop off angle of the roof...
-And the wheelie bar, what if the upper supports were placed at the trunk line and then the sides and underside enclosed to form a boat tail.

I mean it works wonders for us @ 60mph, but what about 160?

You guys have me thinking of all kinds of crazy stuff ... but Hmmmm

[whokilledthejams]

I'm no engineer, but the issue with drag racing is that downforce is a bigger concern than a low Cd. It's not like a salt flat car, for which acceleration can be quite leisurely while running on a dry lake with zero obstacles. A dragster, on the other hand, is all about traction, and making sure you don't hit the other car, or barriers.

If anything, adding a kammback and wheel skirts wold just be added weight in this case.

Of course, if anyone here actually is current on their pro-street drag racing, feel free to correct me.

[MetroMPG]

Interesting question. I don't think skirts over the wheels would negatively affect lift, and they would reduce drag. Done in carbon fibre, they'd add a negligible amount of weight too, so I'd say they'd be worth it.

[Cd]

It now seems to be a standard practice to aero-mod drag cars.
I have seen several drag cars that completely delete the grill opening for better aerodynamics.
They would have no other reason than aerodynamics, since - if anything- the engine would need more air not less.
Also, I have seen several cars that extend the trunk out for better aero.
Rather than just have a huge spoiler at the back like a NASCAR racer, these cars actually extend the trunk out a good foot or two to manage the airflow better.
I don't have a picture handy, but there is a 10 second Supra with this sort of deck lid extention.

So... yes aero mods would help.

I have to wonder how much though, since even a drastic reduction in drag would only be beneficial for the few seconds that the car is running down the track - but then ... in a sport that places the winner by 1000ths of a second, anything helps !

[Cd]

Note the plugged grill, as well as the decklid extention that goes straight out insead of upwards like a traditional spoiler.

[Otto]

At speeds above ~30 mph, the main load the engine must overcome is aerodynamic drag, per recent German research.

So, yes, aero mods would definitely help that car to improve its acceleration and top speed, IF weight is not significantly increased.

[meemooer]

rear wheel covers would help on a full bodied car, like the above pictured. The drag bars are aero in their own way, they are a thin as needed to withstand the forces, and they are round. Traction is more important then aero. Thats why drive wheels are fat, and steer/coast wheels are skinnys. If they were to enclose the drag bars, that could throw the entire chassis setup way off. So i'm sure they've tried it, just not enough.

If anything, how about someone with a Kammback or any of the aero mods that are removable, spend a day at your local 1/4mi on a test and tune night. I guess i could with my truck if i had a tonneau cover and could rev my engine past 3500 rpm without fear of the problems just exploding i would.

[trikkonceptz]

I understand that the traction bars are efficient in themselves, but what if they were used as a frame for a boat tail? Then they would have function to keep traction plus be integral in cutting the rear end wake of the car.

At this level, we are talking about pieces made out of CF or other very light weight materials. But is there any reaon that a FWD dragster cannot side skirt both front and rear wheels? If you look at the pic I posted, there is no way those wheels turn to any practical degree.

[SuperTrooper]

Originally Posted by trikkonceptz

I understand that the traction bars are efficient in themselves, but what if they were used as a frame for a boat tail? Then they would have function to keep traction plus be integral in cutting the rear end wake of the car.

At this level, we are talking about pieces made out of CF or other very light weight materials. But is there any reaon that a FWD dragster cannot side skirt both front and rear wheels? If you look at the pic I posted, there is no way those wheels turn to any practical degree.

Dealing specifically with the FWD racer in your original post: skirting the wheel openings would be the obvious direction. The front air dam appears to be widened to allow turning of the wheels, as well as generate front downforce for traction. Whatever kind of car it is, it's pretty slippery as is. Adding a boat tail might help the overall Cd, but you have to watch weight and where you put it. In contests of acceleration weight is a major enemy.

[Otto]

Originally Posted by trikkonceptz

I understand that the traction bars are efficient in themselves, but what if they were used as a frame for a boat tail? Then they would have function to keep traction plus be integral in cutting the rear end wake of the car.

At this level, we are talking about pieces made out of CF or other very light weight materials. But is there any reaon that a FWD dragster cannot side skirt both front and rear wheels? If you look at the pic I posted, there is no way those wheels turn to any practical degree.

Bingo. Using the traction bar frame to support a boat tail would more than pay for any penalty imposed by the slightly extra weight of the boat tail material. Since the front wheels don't have to turn much in a drag race application, may as well cover them.

The nose cone/bumper cover of that red car are pretty good, but could stand some improvement.

Got undertray? Wheel fairings?

PS: Do the rules require the drag bar to have a wheel on each side, or could you make a presumably lighter drag bar by tapering to just one centerline wheel, perhaps a bit further back? That would make a nice frame for a teardrop boat tail, while still doing its drag bar function.