Custom Vehicles

So im making a race map and you can race with bots too. The car works fine, its using my own script but theres a problem. Nothing i do in my .txt file makes it faster. Increasing the horsepower or mph doesnt work for some reason. I know the script works cuz if i change the rpm to too high it makes the car fly but it wont change speed, not only that but it has to remain with the buggy model or else the map crashes ;/. Hammer’s acting weird. The only thing i’ve done to change the speed is inside the npc_vehicledriver but it has a limit.

P.S. Thanks in advance

Can you post your script?