new exhaust and manifold

Your engine shouldn't be able to move that far, it should only be able to vibrate when it needs to not actually move (or rock or anything else). If it can then fit Superflex poly-bushes to the steady bar. And I mean Superflex not anyone else, the one they make for the steady bar is incredible.

the manifold is only about 4mm away from the body. i do need new bushes in my top engine steady, perhaps this will cure it

i am a little disapointed, from what i understood, my previous exhaust was too large, so a smaler one withe a decat pipe i thought would increase performance, but it is no quicker! if not a little slower. it does not blow or anything. does it need the timing changed perhaps? or re tuneing. i thought it may adjust its self being an spi.

Well, it does but if you let it adjust itself it takes many hours of driving to adapt to the new parts. You need to reset the ECU for it to make a faster adaption. Also it doesn't care whether you have removed the CAT or not, it will continue fuelling as if it were still there and there's nothing you can do about that (the SPi cannot be re-mapped or chipped). The CAT on injection Mini's only costs 1 or 2 Bhp at the very top end of the range anyway, it's the carb version of the CAT which kills performance.