Well some food for thought is that 10qucksprt2.5r is at approximately 810 feet elevation there in Minnisota, but arraptor is at about 43 feet elevation there in California. Also heat and humidity (and barometric pressure too as various fronts roll through) can change the effective elevation as much as 4500 feet too. So it will be difficult to impossible to duplicate the performance numbers that someone else gets. Plus the specific prop that one person uses versus the other has a big effect too. Even if both people used the same brand prop, the props can be different. It was worse with wood props before the plastic props became common, as the pitch could be slightly different from prop to prop even if the props all came in the same bag from the same manufacturer.
Years ago when I was younger, it used to bother me a lot when magazine articles and plane kit suggestions stated that you could use a certain engine on a plane and it flew great. But when I lived in Arizona near Phoenix, the plane would barely be able to get airborne and lumber around ready to stall and snap roll with that same plane engine combination. I remember the guys in Colorado had it even worse being much higher in elevation too.
Here in Texas we have 100 degree F plus temperatures and the humidity is 50% to 60% most of the time, more when it is thinking about raining. So the effect on the engines and planes is very noticeable.
I think the real airplane people, drag racers and other racers have charts and graphs (along with copius notes too) that detail the effective air density at different elevations, temperature and humidity. Maybe even spreadsheets and computer programs for it nowadays. The racers have to change things a lot to maintain that peak edge on speed and power as the conditions change.
Here is some more on it
Temperature has the strongest affect on density altitude with a one-degree change worth a 100-foot change in density altitude. Pressure is next with a 0.01-in/Hg change also worth a 100-foot change in density altitude. Finally, a 10 percent difference in humidity can also affect the density altitude by 100 feet.