I have just fitted a JCW turbo to my N14 Cooper s, it seems to be dumpling boost when I go WOT. I'm sure I've read somewhere that I will need to fit a JCW map sensor but I can't find any posts again to confirm that. Dose any one have any experience with this? It has a Manic stage 1 map and is running fine when I put it back to standard. Also it is the older n14 without a MAF sensor and it has everything on it for a stage 2 if that makes any difference. Thanks.