I had to do a double take the other day.

You know, it’s when you hear something so incredible that you shake your head in disbelief.

Then you wonder if you heard what you thought you heard.

I heard a professional dirt late model driver was making fun of the contraption (Rumley device) that Jonathan Davenport used to smoke everyone near the end of last season.

Wait … he smoked everyone for around three months and no one could figure it out.

I can see getting beat one or two weeks, but for three months?

Now, I don’t think I’d be poking fun.

Actually, if I ran a professional late model team against them, I’d be embarrassed.

I myself am actually embarrassed I didn’t figure it out until after the season. I’m going to chalk it up to laziness on my part … burnout … whatever.

But, I don’t even race with those guys. I really think all those guys need to eat a little humble pie, lick their wounds and work twice as hard to make sure they don’t get smoked like that anymore.

I can’t believe the arrogance in some of these teams.

Anyways, let’s move on.

Let’s talk today a little about aerodynamics.

We all have our ideas on what we concentrate on. I have my own. And, below is a little check list of things that I keep in my mind as I put a body on in the mid winter rebuild.

First, the basic principle of aero as I see it.

Put more air over the car and get rid of the air from under the car.

For late models this means sealing the front of the nose when the car is at running attitude.

Unfortunately on modified you can’t do this. And also unfortunately, tires in open air create lift.

This also means the right side door because our cars, on dirt, do run at a yaw angle to the left.

In reality, I’ve been considering the right side of the car as part of the front of the car and the left side of the car as the rear.

Which leads me to the next point of getting the air out from under the car.

As air passes over a surface it can create a vacuum effect if it passes over an opening in the panel. The goal is to get the front to stick out in the air further than the rear.

This means when it passes over a wheel well have the front of it covering the tire and the rear tucked in behind the tire.

When looking at the right rear tire from the back, I get the front of the wheel well flared out and behind the tire pulled in.

This will create a vacuum of air out from under the car as air passes over the right rear wheel well. Creating more down force on top of the car.

The next thing I concentrating is getting as much air as possible out of the rear of the car. Make the rear as open as the rules allow.

Remember when I said I’ve been treating the left side of the car as the rear.

There has been a movement i late models lately to get the left rear wheel well as small as possible. I don’t understand this.

I like them big so you can get as much air out from under the car as possible. I flare the front of the wheel well out and make it as big as possible without looking ridiculous.

I also unshroud the spoiler.

The trend in late models is to have a center spoiler brace on the spoiler. I noticed a couple years ago when scraping mud off a car that there was never any mud just to left of that spoiler brace.

To me, that meant the air wasn’t hitting that part of the spoiler because that spoiler brace shrouded the left side of the spoiler.

I think we are giving up down force on the spoiler because of that spoiler brace.

We started putting an “old fashion” spoiler brace rod to hold the middle of the spoiler.

Your grandfather might remember these from before it became fashionable to put that center spoiler brace in.

The most important thing is to just analyze every part of your aero. Have fun with it. Make it a game and …

We’ll talk soon.

Be safe,

Kevin