Bump Drafting 101

2009 Daytona 500 080

This Sunday will be NASCAR’s second installation of full throttle restrictor plate, bump drafting, 185 MPH three to five wide place swapping, hope he doesn’t make a mistake, high stakes racing from Talladega Superspeedway in Alabama.  The four restrictor plate races , two each from Daytona and Talladega are  always very exciting from the fan’s point of view.

From the picture above, you can see that the COT has made bump drafting a little less hazardous in 2009.  In the old cars, the front and rear bumpers did not match up at all in height.  The old cars had a very aerodynamically designed front end, very tapered and low slung.  The rear ends of the older cars had their rear bumpers a little higher above the ground than the COT cars.  So if someone was trying to bump draft, the back car’s front bumper would actually get underneath the rear end bumper of the leading car and lift up the cars rear end off the ground.  That would, at times, lead to some very unpleasant results!  With the old cars a bump draft almost always lifted the leading car’s rear end off the ground, causing havoc! As the lead car, you only wanted a bump draft when you were going perfectly straight!  If you weren’t going perfectly straight when the bump draft occurs, the front car risked being turned sideways at 190 MPH!  That would cause that driver to be ALL  HAIR, TEETH, AND EYEBALLS!!

Now both the front end bumpers and the rear end bumpers are all most equal in height.  That allows the two car’s bumpers to more closely aligned and allow for bump drafting with far less consequences for the lead car!

Everyone  remembers the “Big One” that  Carl Edwards caused at Talladega last year.  That was crash was caused because Carl Edwards tried to push or bump draft with Greg Bifle going into the turn.  Even tough the bumpers are more closely aligned with the COT, bump drafting in the turn will still turn the lead car around.  That is exactly what happened to “The Bif”!  Thereafter, all hell broke loose!!!

Now having explained the basic aerodynamics of drafting, you could now see how teammates, or any two cars, could hook- up and push or propel themselves to the front of the pack.  With two cars hooked-up in line drafting and powering their way forward, together they only punch a hole in the air the size of one car with more horsepower than a single car.  That would allow them to march to the front.   Conversely, side-by-side racing would be much slower because of the huge hole in the air that the two cars would produce and also creating significantly more dynamic and static drag on the cars to try to overcome.

Having tried to explain some of the basics of drafting and looking at the above picture, just remember that one picture is truly worth a thousand words!!