Mario Kart Style Drifting

Hey guys,

I'm working on a Mario Kart style racing game, and I'm doing the kart controller script. Basically what I have here is really rough but this is what I have so far, I'm going for rigidbody based movement.

What I'm looking for is a little advice on doing this, as I've never programmed a vehicle before and it doesn't 'feel' great, it works, but something just feels wrong (it seems to 'stick' to accelerating for a second before reversing, and vice versa). Also the drifting code is super basic but I'd like to get something very similar to Mario Kart's drifting system.. as I'm a bit new to applying rigidbody forces like this, I just wanted to hear your thoughts on it.

Here's my code:

 void FixedUpdate()
     {
         float inputX = Input.GetAxis("Horizontal");
         float inputY = Input.GetAxis("Vertical");
 
         isDrifting = Input.GetKey(KeyCode.Space);
 
         if (inputY > 0)
         {
             // If we are going forward
             if (currentSpeed < maxSpeed)
                 currentSpeed += acceleration;
         }
         else if (inputY < 0)
         {
             // If we are going backward
             if (currentSpeed > -maxReverseSpeed)
                 currentSpeed -= decceleration;
         }
         else
         {
             // If we are stopping
             if (currentSpeed > 0)
             {
                 currentSpeed -= decceleration;
             }
             else if (currentSpeed < 0)
             {
                 currentSpeed += acceleration;
             }
         }
 
         if (!isDrifting)
         {
            // Set the drift direction while not drifting (we can't change direction mid-drift!)
            
            if (inputX > 0)
                 driftingDirection = DriftDirection.Right;
             else if (inputX < 0)
                 driftingDirection = DriftDirection.Left;
         }
 
         // Apply currentspeed as rigidbody velocity
         this.rigidbody.velocity += transform.forward * currentSpeed;
 
         // Handle kart drifting
         if (isDrifting)
         {
             if (driftingDirection == DriftDirection.Right)
             {
                 // Drifting right, add some velocity from the left 
                 this.rigidbody.velocity += -transform.right * driftingSpeed;
                 this.rigidbody.AddTorque(transform.up * 1 * steeringAngle * driftingAngle, ForceMode.Acceleration);
             }
             else if (driftingDirection == DriftDirection.Left)
             {
                 // Drifting left, add some velocity from the right
                 this.rigidbody.velocity += transform.right * driftingSpeed;
                 this.rigidbody.AddTorque(transform.up * -1 * steeringAngle * driftingAngle, ForceMode.Acceleration);
             }
         }
 
         if (!isDrifting)
         {
             // Turn normally if not drifting
             this.rigidbody.AddTorque(transform.up * inputX * steeringAngle, ForceMode.Acceleration);
         }
  }

 

I'd really appreciate any advice about how to handle these sort of physics. This is on a rigidbody that is not using gravity by the way, I will be handling my own 'stick to rotation of the road' code to stop the kart from being able to turn upside-down.

Thanks, -Ben