[Nero_3D]

try that

pawn Код:

CMD:transform(playerid, params[]) {
    new
        vehicleid = GetPlayerVehicleID(playerid)
    ;
    if(vehicleid) {
        new
            Float: x,
            Float: v,
            Float: v,
            Float: a
        ;
        GetVehicleZAngle(vehicleid, a);
        GetVehiclePos(vehicleid, x, y, z);
        switch(IsTransFormed[playerid]++) {
            case 0: (_: a) = CreateVehicle(infernus, x, y, z, a, 0, 0, 15);
            case 1: (_: a) = CreateVehicle(rancher, x, y, z, a, 0, 0, 15);
            default: (_: a) = CreateVehicle(hydra, x, y, z, a, 0, 0, 15);
        }
        GetVehicleVelocity(vehicleid, x, y, z);
        SetTimer("PutPlayerInTransVehicle", 0, false, "iifff", playerid, _: a, x, y, z);
        SendClientMessage(playerid, 0x33AA33AA, "You have transformed your vehicle!");
        DestroyVehicle(vehicleid);
    }
    return true;
}

pawn Код:

forward PutPlayerInTransVehicle(playerid, vehicleid, Float: x, Float: y, Float: z);
public PutPlayerInTransVehicle(playerid, vehicleid, Float: x, Float: y, Float: z) {
    PutPlayerInVehicle(playerid, vehicleid, 0);
    SetVehicleVelocity(vehicleid, x, y, z);
}

And the GetPlayerSpeed function you got is another fail
Search for one which actually uses the pythagorean