Conditions of Warranty

1. Racer is required to have a weather station that includes:
   a.  barometer
   b.  wet-dry bulb or hygrometer that measures humidity.

2. Make 3 runs with existing headers and record weather conditions from your weather station as well as the weather conditions from 2 other racer's weather stations.  (We acknowledge there may be measurable differences.)

3. Change to Stahl Headers and make 3 more runs recording the weather from all three stations.

4. Change back to original headers and make 3 more runs noting the weather conditions from all three stations.

5. Send the data to us.  We will use the computer program "Weather.exe" (click if you wish to download the program) to calculate the corrected vehicle performance as affected by weather for each run.  

The history of this program goes back to the early Mopar factory race group headed by Tom Hoover.  It is our understanding that Tom asked George Wallace (who was a Chrysler engineer at the time) to come up with a system that would allow them to correct for weather conditions influence on engine power and resulting car performance.  A magazine article (including charts) that may be used to manually correct appeared on page 95 of the August 1972 issue of Hot Rod Magazine.  This program has no consideration for track condition, altitude change of the track or for wind conditions.   

The Hoover group carried a laboratory mercury barometer and a wet-dry bulb made by George Instrument Company.  The system and algorithms were turned into a computer program for a Radio shack Model 100 at the direction of Arlan Fadley.  Any time you have heard Warren Johnson make reference to a run correcting to such and such, he was making reference to this program.  Arlan was kind enough to provide us with a copy of the model 100 source code and we turned it into an Intel Pc based computer program.  We have over 2 years of data from a well known pro stock team who ran the same set of cylinder heads for 3 years and are very comfortable that the program is produces reasonably accurate results for the intended purposes.

6. If in the event that Stahl Headers did not produce a performance gain, the customer will have to ship the headers back to Stahl in good condition with no dents and the customer will be responsible for freight both ways.  

7. Any warranty claims must be accompanied by copies of the strip timing slips and weather data from 3 sources as described above.