Does Aero Matter on Dirt?

jaymancds

Premium User
I was thinking about this as I drove into work this morning, does aero affect dirt oval karting on a large scale? I understand that with speedway karts and sprint karts its a huge deal, but for the small dirt oval tracks all over the country, does aero matter?

Hypothetically, if I don't have enough front grip, I could swap bodies to one with higher nose downforce and see a performance change. And vice versa. If it doesn't matter on dirt ovals, then why are there so many types of bodies? I know some just look cool, but are they hurting, or maybe helping performance at all? Could you win a race without a body if the rules allowed for it?

I have my suspicions, but I figured I'd ask everyone what their thoughts are.
 
On smaller Dirt oval I'd say NO not enough to notice for 99% of the guy's the Pro's might figure they gain a 100th with a certain body, Yes you can win a race with out a body, For most racers if they changed a body and got faster it was most likely because the first body was not mounted properly binding the chassis, and they got it right mounting the second one, nothing to do with air dynamics, However even on dirt oval but big tracks 3/8th mile and bigger, IF you consider Air dynamics part definition as running faster in a draft ( pack ) of 3 or more, Then yes because a pack will pick up speed.
 

KKania17

Member
I try not to get too caught up in it, but if you stick your hand out the window driving down the road....lol. I’ve tried some creative stuff on the bigger tracks, whether it helped or not I doubt it.

I remember about 10 years ago Andy Burkholder blew his body off and got 3rd I think at Albany Saratoga on the big track (1/2 I think?) with just 4 number plates. I wonder if the bodies we run cause drag?
 

jaymancds

Premium User
I try not to get too caught up in it, but if you stick your hand out the window driving down the road....lol. I’ve tried some creative stuff on the bigger tracks, whether it helped or not I doubt it.

I remember about 10 years ago Andy Burkholder blew his body off and got 3rd I think at Albany Saratoga on the big track (1/2 I think?) with just 4 number plates. I wonder if the bodies we run cause drag?
I've considered the drag, certain bodies, noses specifically seem to be much more brick like in their shaping. Sharper edges, more square lines, etc would create higher drag. I spent my first two years in college working on aero dynamics for aerospace applications, so I just find it interesting.

Could we be hindering our karts abilities with one body over another, is too small of a difference, has it ever been scientifically tested, etc. These are all questions I was thinking about.

As an example, a TRJ swoop, a TRJ highside, and a TRJ force all side by side on the same kart and setup etc. The Highside would theoretically have medium nose downforce, but very high side force. The swoop would have slightly higher front downforce over the drivers feet, medium side force, and dissipating pressure off of the back. The Force body would have low downforce over the drivers feet, but the highest downforce directly over the front tires, medium side force, and a large area of low pressure off of the back. All hypothetical, but looking at the pictures of all 3, that would be my hypothesis.

Anybody's kid need a science fair project?;)
 

Bumpy

Member
Supposedly drag only starts taking a drastic effect at ~50mph.
However, bicycle riders think it's important.
It does make sense that any Kart body that cut thru the air better
would be faster.
 

XXX#40

TRUMP 2020
Supposedly drag only starts taking a drastic effect at ~50mph.
However, bicycle riders think it's important.
It does make sense that any Kart body that cut thru the air better
would be faster.
aero is nasty on a kart, big open hole, and a rider that isnt so aerodynamic
 

Ted Hamilton

Design Drafter / Racer
"If you can't make it slippery, punch a hole in the air and drive through it." -- aerodynamicist in reference to karting.
 

cmac

Member
I am not an expert on this matter, but I would say Kermit Buller and Ralph Woodard from Henderson NE & Omaha, NE are. Kermit is is many things--manufacture, designer, engineer, inventor etc. and Ralph has probably won. as many or more, important two cycle dirt oval races as anyone in the country. In the period I observed them (late 1980's-1990's) they ran wedge body works that had massive side panels and wings similiar in appearance to Winged Sprint cars. I have to beleive they would not have went to all the trouble if they did not work. To that extent, they were mainly running higher horse power, faster two cycle classes, and their body work (and anyone else who hoped to beat them) was much more exaggerated than the typical bodywork I see on the karts of today's 4 cycle class competitors. So, it makes me wonder if perhaps dirt oval aerodynamics might be put into two distinctly differenty categories: (1) slipping through the air, (2) using the air as a cushion to effectively lean against in trying to turn through the corner? Perhaps someone with Kermit's or Ralph's level of understanding will choose to chime in on this thread? CMac
 
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