I'm lost with this especially with a 60-1 compressor wheel. I would start at the beginning by not using that tornado.My friends car with a Ta62 wasn't surging or acting stange at part throttle. I don't see why you need a tornado at this point.The intake plumbing is short and straight, no MAF either. Look at the picture that is straight into the tornado. You can see the inside of the K&N cone filter. The filter is about a foot long.
RemoveBeforeFlight