GearBox in Car

using UnityEngine;
using CnControls;
using System.Collections;

public class GearBox : MonoBehaviour {
public car car1;
public GameObject pointerSpeed;
public GameObject pointerRPM;

public float maxPitch=2.4f;
public float[] totalSteps;

public AudioClip rollingSound;
public AudioClip engineSound;
public AudioClip skidSound;

float highVolume = 1;

AudioSource rollAudio = null;
AudioSource engineAudio = null;
AudioSource skidAudio = null;

float currentPitch = 1;
float rollPitch=1;
float procentPitch;
float timeToShift=0;
float speed;

bool shiftinGear;
int currentGear = 1;

Quaternion pointRot;

void Awake(){

rollAudio = gameObject.AddComponent<AudioSource>();
rollAudio.loop = true;
rollAudio.clip = rollingSound;
rollAudio.volume = 0;
rollAudio.spatialBlend=0.8f;
rollAudio.Play();

engineAudio = gameObject.AddComponent<AudioSource>();
engineAudio.loop = true;
engineAudio.clip = engineSound;
engineAudio.volume = highVolume;
engineAudio.spatialBlend=0.8f;
engineAudio.Play();

skidAudio = gameObject.AddComponent<AudioSource>();
skidAudio.loop = true;
skidAudio.clip = skidSound;
skidAudio.volume = 0.1f;
skidAudio.spatialBlend=0.8f;
}

void Update(){
speed = GetComponent<Rigidbody>().velocity.magnitude*3.6f;
}

void FixedUpdate () {

procentPitch = Procents(maxPitch-1,1);
Transmission();
pointerSpeed.transform.localRotation=Quaternion.Euler(Mathf.Abs(speed)*-0.9f,-90,0);
pointerRPM.transform.localRotation=Quaternion.Euler(-70*(currentPitch-1),-90,0);
Sound();
}

void Sound(){
rollAudio.pitch = rollPitch;
if((speed/20)<0.7)
rollAudio.volume =speed/20;
engineAudio.pitch = currentPitch/2;
if(!shiftinGear&&engineAudio.volume <currentPitch)
engineAudio.volume +=0.05f;
}

float Procents(float value, float procents){
float newValue = (value/100)*procents;
return newValue;
}

float ProcentOfValue(float firstValue, float secondValue){
float newValue = (int)(firstValue / (secondValue/100));
return newValue;
}

void Transmission(){
float difference=0;
float tempSpeed=0;

if(CnInputManager.GetAxis("Vertical")>0){
if(!shiftinGear){
for (int i = 1; i<totalSteps.Length; i++)
{
difference=totalSteps[i+1]-totalSteps[i];
tempSpeed=speed-totalSteps[i];
if(speed>=totalSteps[currentGear+1]&&currentGear==i)
shiftinGear=true;
if(speed<totalSteps[i+1]){
break;
}
}
currentPitch =Mathf.Lerp(currentPitch, (1+(procentPitch*ProcentOfValue(tempSpeed, difference))), 0.1f);
if(currentPitch>maxPitch)
currentPitch=maxPitch;
timeToShift=0;
}

}
else{
currentPitch=Mathf.Lerp(currentPitch,1,0.05f);
for (int i = 0; i<totalSteps.Length; i++){
currentGear=i;
if(speed<totalSteps[i+1]){
break;
}
}
}

if(shiftinGear){
if(engineAudio.volume>0.2)
engineAudio.volume -=0.05f;
currentPitch=Mathf.Lerp(currentPitch,1,0.01f);
timeToShift+=Time.deltaTime;
if(timeToShift>0.5){
shiftinGear=false;
currentGear+=1;
}
}
if(currentPitch<1)
currentPitch=1;
rollPitch=1+(procentPitch*ProcentOfValue(speed,100));
}
}