I Owe Proton Preve CFE and FLX CVT, I don't think can add-on more speed on stock engine bro. My friend clock 190+ km/h with 1.3 FLX stock engine without any tuning. After he change this and that the whole car performance drop and FC keep on increasing

Now he still wanna go for ECU tuning for RM80... Haiz By the way, I still happy driving with original setting and only returning for ECU and TCU re-flashing once in a while at SC