Cool Stuff You Never Knew About Funny Car Headers

If You've Ever Watched a Top Fuel or Funny Car Dag Race

You've probably seen a high angle shot taken down track (from the end of the track), which tends to expose all sorts of handling contortions while the car is under power. One of the most common occurs when a "cylinder goes out", meaning combustion is no longer taking place in one or more cylinders. When that happens, the car will usually begin to violently veer off to one side or another. 

This slo-mo video clip will help identify the condition. As you watch you'll see the headers on the left side of the car spewing out raw fuel as the car starts to veer left towards the center line of the track.
Here's another example in "real time"

So Why Does That Happen?
While the same conditions can occur in a Top Fuel car, the results are much more noticeable in a Funny Car. The first reason is the Funny Car body develops a tremendous amount of down force, where as a Top Fuel car relies on spoilers for similar effects. 

The second, and the one most people either don't know or tend to forget, is each exhaust pipe delivers approximately 800 pounds of thrust. So if you lose between 800 and 3,200 pounds of thrust on one side of the car, the force from the opposite side will shove the car towards the weak side.

A "Funny" Thing Happened On My Way Down The Track
If you've been keeping up with Drag Racing, It was last year when car crews started making modifications to their cars to deliver massive strides in performance. All of a sudden, week after week, records were being blown to pieces.

One of These Things is Not Like The Other
Can You Spot The Difference?
Ron Capps 2012 Car                             Source: NAPA Auto

                                                         Ron Capps 2016 Car                               Source: NAPA Auto
It's the angle of the headers. With all of thrust being unleashed as the car powers down the track, laying the headers back is like throwing on a "hidden" rocket pack. It also did not take long for other teams to begin figuring this out.

Surely That's Cheating?
No it's not, and please stop calling me Shirley, but NHRA has stepped in to say "enough is enough". They have placed a limit on the acceptable exhaust angle to be no greater than current.  

Of course with that decision came great debate amongst drivers and their teams, some calling for the return of previously accepted angles and others calling "foul" for "exposing" it. So we guess the old saying is true, "It's not the size of the pickle, it's the angle of the dangle". (OK, two bad jokes, we're done)
First to figure out "rocket thrust" - Source J. Burghardt
Header Angle Has Become Yet Another "Tuning Tool"
Again after watching an afternoon of NHRA drag racing, you will watch the challenge of tuning the cars to match track conditions. If starting line traction shows to be an issue, crews will begin installing headers with a more upright angle to create more down force. When the traction is good, they will change headers to create more propulsion.
Close to body and laid back 32 degrees
Standard angle and farther from the body
One side note of the change is as the angle became more laid back, the headers have to be closer to the body to work correctly. The result is the exhaust is now burning the body wrap. To hide this from other teams, those employing the laid back design began using body wrap patches thereby disguising conditions. So, another "trick" has been exposed, the 32-degree angle is as far as the rules makers are going to allow and we wonder what the next "innovation" will be.

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