I can manage to go 175kmh on my wira 1.5 manual (aircon-off)
It can still rev higher but I did do so as at 175 it's revving at 5.5K RPM.
In order for you to achieve high speed, I got an open pod air filter (K&N) to fed in more air into the combustion chamber. Besides that, i used Shell V-Power at that time because this fuel can burn more efficiently compared to the ordinary fuel at high rev. Coupled with good springs and absorbers from Koni & Apex (lowered 50mm), the car is rock stable at high speed.

Wira 1.5 auto transmission only has 3 speed/gears. That is why you feel the car is sluggish during pick up. Other cars with auto tranmission has 4 speed/gears.