Hello, new to the forum and not entirely sure where to post this, but I've been having an ongoing issue with my R53 Cooper S for two years and can't find anyone or anything to fix the issue. Hopefully someone in the Mini Community has had a similar issue and can point me in the right direction!



The Car- 2005 Cooper S with 97k Miles, Manual, 15% WMW Reduction Pulley w/ One Step Cooler Plugs, CravenSpeed Cold Air Intake, ATI Super Damper, JCW Copy Catback Exhaust, and Stage 1 Tune(Only had it tuned to try and fix issue).



The Issue- So under hard acceleration, wide open throttle from about 3k-4k RPM and up, I have a predetonation/lean condition pinging or pinking noise. I can drive it spiritedly through the gears at about 50%-75% throttle and don't get the noise but the moment I push the throttle that little bit further immediately the noise starts.



Now obviously some might say just don't go WOT but its a mini what's the fun in that? I always use 93 octane fuel from either a Shell or a Mobil 1 station so don't think bad or low octane fuel is the issue. I also recently put a couple of gallons of 110 race fuel in it and that cleared the issue. I continued to put a gallon at time of 93 on top of that diluting it, to see at what point the noise would start again and it got to a rough guesstimate of probably 95 octane to wear the noise was still not there.



I've also made sure there are no vacuum leaks on the engine, I know the charge pipe to the super charger is prone to warping and not sealing properly but mine is fine. I replaced the bypass valve with the upgraded Detroit Tuned one. I've replaced both MAP sensors, the fuel filter is new, Injectors have been cleaned and tested, Supercharger has been removed and serviced. Also recently just did new timing chain, guides and tensioner, new coil and plug wires, new camshaft position sensor, new Bosch o2 sensors, new PCV valve, and purge tank vent valve.



As you can see I've dumped a lot of money and time into this car chasing the issue and its just super frustrating. When I was a kid my father had a car with the exact same mods and never had this issue so I know I haven't gone too far with the mods, there's just something stupid I'm missing.



I look forward to hearing what people may come up with, and thank you in advance for any information you can give me!