My Yaris accelerate too slow !!! any suggestions ??

[eTiMaGo]

my question is, how long was it between you doing 180km/h and your next try that only did 160? Did you have the other mods too at that time?

Like tk-421 said, wheels can affect rolling resistance, your exhaust and intake might actually increase mid-range torque a little, but reduce top end power, it's hard to be sure.

I suggest you to check and clean your air filter. I let mine get real dirty over time, and it really sapped a lot of power, made a huge difference when I finally cleaned it up!