1) One who reads the week's parsha - shnayim mikrah v'echod targum, in a timely manner (finishing before the Shabbos day meal), will have his days and years lengthened. (Berachos 8a-b, Orach Chaim 285 and many commentators)
2) Doing this specifically on Friday is a segula to be able to connect one's thoughts to his words in his davening on Shabbos. (Bas Ayin)
3) It is said over from tzadikim that reading the parsha - shnayim mikrah v'echod targum is connected to parnasa, therefore, if one does it without any interruption he will have parnasa without interruption.
4) It is accepted among Chabad Chasidim to learn every day Chumash and Rashi from that week's parsha. The Rebbe's of Chabad say that reading the parsha twice and targum once is halacha. Rashi, however, is for Yiras Shomayim since the Shulchan Aruch says "Yirei Shomayim read targum and Rashi, meaning, Rashi is a segula for Yiras Shomayim. (Segulas HaBeShT)