Let's be clear, when you overclock an XE Core i7, you 'll be using the Turbo max ratio as the max ratio ... YOU WILL NOT GET TURBO KICK IN WHEN YOU ARE OVERCLOCKING. Turbo IS the way you ll over clock, then, you ll be using the stock clock (133MHz) and you will increase it...
I recommand that you do not max out the Turbo ratio, and do a trade between Turbo ratio and clock increase via the base clock. This gives the best frequency results.