I have been trying to use Forzatune 7 to get a base tune and learn the fundamentals of tuning my cars on my own. While the suspension tuning usually turns out very good anytime I upgrade the engine/turbo etc and use the gearing tuner on Forzatune, my launch is always terrible. It seems like the calculator just tries to achieve the highest max speed possible without regard to launch. Is this something others have seen and am I using the calculator wrong in some way? Thanks in advance its my first post.
Same here. Horrible tunings for Forza Horizon 4. I have a massive anmount of Driftcar-Tunings because FT7 makes all cars slippery as hell.
Try to ask “Don Joewon Song” for help. Maybe he will answer you on youtube. 
you can try out the calculator at http://ftc.bg55.com You can fine-tune your first gear, top speed and final drive when calculating the gearbox tune.