I didn't say to overclock the CPU. I said if you're NOT overclocking the CPU, then you should leave the default settings, which means the Turbo core, alone. You will get lower performance by disabling the turbo core and it really won't decrease your temps much unless it's a laptop, which it's not.
Are you having temperature issues with the default configuration? What are your current idle and load temperatures? One exhaust fan is probably not sufficient, especially if you're in India or a region with high ambient temperatures. Positive pressure, with more intake fans than exhaust, is good to keep dust out, but not much good for cooling performance. You really want either an equal number of intake and exhaust fans, or more exhaust fans than intake. Since your case model does not support further exhaust fans, I'd seriously consider a different case or modifying your case to accept a top fan for an additional exhaust if you are having temperature issues.
If you're not having temperature issues, then I'd leave things as they are.