i might have asked this before at some point, but what the hey... it has to do with gearboxes on intake-restricted cars(gtal/itcc/ufbr), but also gearboxes in general.

how do people come up with gear ratios for those kinds of setups?

sure, it's easy to take the RACE_S gearbox, and move the final drive ratio, but is that the most efficient way, or just the easiest?

if you decide not to move the FDR and change the gears themselves, does that have the same effect on top speed without causing an acceleration hit during some point of the powerband?

i probably just asked a lot, so feel free to bang out a lengthy answer.

What i usually do to find an appropriate gearing: First im checking the cars data, where is the torque max. and where the power max. Those values also change when moving the intake slider. I prefer to adjust the gears directly, not only finaldrive.

Then i do a normal start, of course in 1st gear, and check how much the rpm drops and adjust it in a way that it doesnt fall below the max. torque rpm. Next step i find out the last gear: driving some laps and checking if it comes close to max rev at the fastest point of the track. When adjusting i always let some space for drafting...

Final step after that: i load this set into VHPA and let it calculate the rest. Maybe i have some points at the track where i want to drive in a specific gear: i note that gear ratio if i already have the correct value and move the 'progressive slider' in vhpa gearing calculations box till it fits. Of course i try to adjust specific gears after that, so for instance i want to have max power when it goes uphill, or i want to have the best accel out of a key turn, i try to find a ratio where rev are between max torque and max power.

The curves and tables vhpa offers also shows you then when to shift (after we lost the shift indicator light lately)

i jsut find something that i dont overrev in the slow corners