Transiting through Istanbul Ataturk

Hi Guys. I'm flying to Benghazi via Istanbul on Turkish next month and am wondering if we need to clear immigration if we are connecting in Istanbul. My bag will be checked through as everything will be on the same PNR, so rechecking everything isn't an issue.

Thanks!!

I have transited through IST a few times in the past couple of years and have never needed to clear/pass immigration. Nice airport as well.

Will fly though IST next May on my way to Baku.

Iain

Does anyone know how big Istanbul airport is? I'm at LHR right now and because of a weather delay I will have 45min maybe less to make my connection? Both the incoming and outgoing flights are on Turkish and arr/dep T1.