One of the things I have found is that one needs to perform a sort of Pareto, or ABC analysis on his Forza efforts. You know, the old Bell Curve - where the Y axis is Elapsed Time, per Track, per Class, or Overall, and the X axis is effort, say in man-hours. Now, judging by what I see on the leaderboards, the most common condition is "Piss on it" and start up a war game and toss Mr. T bombs around.
Next would be to take a stock car for the class and to run a "One and Done" on the track. Minimalist effort for the most improvement. 1740 seconds off for 60 seconds effort. If you did that for every track in every class, you would wind up fairly close to the top, mostly cause there are a big bunch of the "Piss on it" kinds of guys.
From there it sort of depends on what kind of guy you are, and let me guarantee you this - I make no judgements here. You can put an hour into tuning and practice and knock maybe 10 seconds off. Another hour and maybe get another 2 seconds. But it won't take long and you are dealing with multiple hours to get a tenth. When is enough enough? Sooner or later you have to draw a line.
My line is "failure to improve in two straight 5 lap races". That is when I decide that I have this car as good as it is going to get at this time, and I move on.
I guess what I am saying is, we all have to draw a line - "this is the amount of effort I am willing to expend towards this result." - and then learn to live with it.
And the result will be the perfect garage for you at this time...

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