[Kar]

I made my own little version, I find this one alot better

pawn Code:

#define BURNOUT_INDEX 0.015

forward BurnoutFunc(playerid, vehicleid);
public BurnoutFunc(playerid, vehicleid)
{
    PlayerInfo[playerid][pBurnout]++;
    new keys, ud, lr;
    GetPlayerKeys(playerid, keys, ud, lr);
    if(PlayerInfo[playerid][pBurnout] > 10 && keys == 8)//VEHICLE_ACCELERATE
    {
        if(PlayerInfo[playerid][pBurnout] > 30) PlayerInfo[playerid][pBurnout] = 30;
        new Float:speed[2];
        GetXYInFrontOfVehicle(vehicleid, speed[0], speed[1], BURNOUT_INDEX * PlayerInfo[playerid][pBurnout]);
        AccelerateTowardsAPoint(vehicleid, speed[0], speed[1]);
        PlayerInfo[playerid][pBurnout] = 0;
        KillTimer(PlayerInfo[playerid][pBurnoutTimer]);
    }
    if(keys == ( KEY_SPRINT | KEY_JUMP )) return 1;//keys are still accelerating and braking
    if(keys != ( KEY_SPRINT | KEY_JUMP ) && keys != 8)//keys are now not related to accelerate and brake
    {
        PlayerInfo[playerid][pBurnout] = 0;
        KillTimer(PlayerInfo[playerid][pBurnoutTimer]);
    }
    return 1;
}

#define TURBO_DEDUCT_INDEX 135
public OnPlayerKeyStateChange(playerid, newkeys, oldkeys)
{
    if ((newkeys & KEY_SPRINT) && (newkeys & KEY_JUMP) && IsPlayerInAnyVehicle(playerid))
    {
        PlayerInfo[playerid][pBurnout]++;
        PlayerInfo[playerid][pBurnoutTimer] = SetTimerEx("BurnoutFunc", 100, true, "ii", playerid, Current_Vehicle[playerid]);
    }
    if (RELEASED( KEY_SPRINT | KEY_JUMP ) && !(newkeys & 8))
    {
        if (IsPlayerInAnyVehicle(playerid) && PlayerInfo[playerid][pBurnout] > 0)
        {
            PlayerInfo[playerid][pBurnout] = 0;
            KillTimer(PlayerInfo[playerid][pBurnoutTimer]);
        }
    }
    return 1;
}

Theres a bug in yours, once you hit 10 burnout, it does the burnout

if (RELEASED( KEY_SPRINT | KEY_JUMP ) && !(newkeys & ) fixes it