GR Yaris Stig in GR Yaris tuned by Litchfield

[Onehp]

Is there any calculation for how much power = time ?

I know there’s hundreds of variables but if you have the same car same day, track tyres etc how much time would we think each 50bhp would give on a 1 min lap ??

Very much depends on the track in question I suppose. Typically long/many straights particularly benefit more power... Others, it matters suprisingly little...