To be quite honest, I have only once taken a look on the technical side of things. Looked trough worms tuning guide, did all the math I needed to, and I did this to a car I had tuned by “butt feel”.
The result actually didn’t surprise me much, I was only few clicks away on most things that the math would have resulted.
and I actually occasionally do what most tuners don’t agree with, Adjust the end that causes you problems. In other words if my front end is giving me problems, I might go and adjust the rear end. Although every time I’m doing this I’m accepting that fact that the handling might become fairly loose. how ever, these are very rare occasions.
Also quite often I back out from the tuning side and take another look at the build, as the problem might be there. Usually if I’m building one car to A-600 (Note this is in FM4, roughly equal to B600 of FM5) I usually end up building the car completely over 3-6 times.
Now as I have told how I tune, I will also tell where I use telemetry and why.
-Camber / tire heat telemetry. Just to make sure my tires have equal heat or inside of the tire SLIGHTLY warmer than the outside. The heat isn’t as important over is it left or right tire, or is it front or back tire.
-Springs & damping & ARB’s / Suspensions telemetry. In any case the car shouldn’t bottom out, rest of it is “butt feel”
-Aero / Butt feel
-Brakes / Friction telemetry. Back never locks up before front does
-Differential / Butt feel
-Tire pressure, / tire misc telemetry. Pressure should be 32.5-34 PSI after 3 laps (when the tires have warmed up)
-Gearing, just have to remember that I should never shift while cornering, and I should be right on the power when ever I exit a corner. The situation where I would need adjustable gearbox is fairly low unless the original gearbox has wonky gearing. As most of the time the original gearbox is good enough, at least after sport gerbox upgrade which lets you adjust the final drive. The amount of PI fairly often gives better results when invested on power. How ever in low classes D or lower (in FM4) race gearbox fairly often turns to quite beneficial upgrade, as you highly likely have fairly narrow powerband, and when original gearbox might end up you going from 100-135-100 hp , I consider it more benficial to run from 115-125-115hp range