hello everyone i am kaan from turkey, istanbul. i have 2006 cabrio r53 with a/t. it is 50 000km. ı have started to making some modifications to my mini. first i started with alta's %17 pulley also i have a jcw air filter(with 2 valves) last week i remapped my ecu. but before remapping and after remapping, i realised a problem or maybe it is not a problem but it makes me think in that way. i have totaly no problem in 1st and 2nd gear but while i was running 50-60 km/h in 3rd gear, i put my foot to gas pedal than my car stars to rev and when it hits 4200-4500 rpm, it accelerates more. like a turbo engine's turbo lag. i think this problem (if it is a problem) happened when i changed my fual octane. ı was using 95 then changed it to 97. when i searched web for this issue, i found that it may caused by a spring problem in bypass valve so i replaced it yesterday. when i took the old one, i saw that the spring really makes strange noises when i compress it. so, i changed it with the original one but this issue still continues. if anyone can helps i would be too happy.