Like the others say don?t bother with cheap chips..............as for the viper filter the advantage of an enclosed filter is it reduces the hot air drawn in...the viper kit looks the same as the bmc but £70 quid more...as for the piper cross cone filter,?. minty's old vr had an amd re map piper cross cone filter and a supersprint exhaust all together making for a huge improvement over my standard vr...with regards for generic chips, I?d personally avoid them as no two engines are the same, a generic chip works on standard factory parameters where by a remap will be suited to just your engine