I'm working on making a 2d side-view drag racing game. I've nearly completed the engine torque calculations and have a torque/horsepower curve across rpm generated by a variety of parameters. I need to translate that torque/hp figure to acceleration/speed on an object(the vehicle), based on wheel diameter and vehicle weight, limited by tire grip. I originally intended to use the physics behavior but it seems incapable of doing what I need. Thanks so much guys!
Edit: A bit more detail about some of the things I could use some help with. As I mentioned previously, I have a hp/torque generator from a given RPM(and the ability to draw a dyno curve from that data). But I have yet to figure out how to make it actually behave like an engine, e.g. throttle and RPM drop simulation as well as translating what the engine is doing to the wheels. So limiting wheel speed to engine rpm when a gear is engaged, and dropping rpms to match the next gear when shifting. I have a transmission set up with all the ratios and have a very rough working example but it's not functioning as I'd like, I have to manually specify an rpm drop per gear and unless shifted at redline it's inaccurate. There may have to be calculations regarding engine inertia/momentum and transferring that to the wheels (as well as accounting for vehicle weight) when shifting/as it should. I thought the math for essentially simulating an internal combustion engine was difficult but I can't even begin to figure out this issue. Thought it would be relatively simple but that was under the assumption that the physics behavior could take my torque figure, apply it to a wheel, and be alright... I was mistaken. I'd even consider paying someone if they could put together a template capx with realistic side-view car handling.