Help with nos surg

dr's wife racing wrote:Ok we have a drag radial car with a small block.It is in a fox body.Not trying to do anything cutting edge here but can't seem to get it to work.Primary fuel system is alcohol terminater type set up.runs 6.20 on motor with a nos converter has gone 5.90 with a motor converter.It has a speed tec. two stage plate with -6 lines. with gasoline as fuel for nos. Has a A 2000 pump for nos alcohol is a belt pump. Basic tune is 82 nos 82 fuel have gone down as far 73 on gas jet before things got lean.We start out with 900 to 975 bottle pressure base timing is 34 deg. pull out 6 deg on nos.It has a 7AL3 Box with a power grid Msd gave us the hookup to make this work. The problem is the car surges any time the nos is on.This set up worked flawless on a big block that made about the same HP as the small block. We've tried all kinds of changes in timeing,new fuel pump,different rotor phase's.The power grid was added to try and help. It doesnt make any difference if you use one or two stages or one. All of the above changes effect the way the car runs the surging problem is a constant and does not seem to be effected at all by any thing we have done. I would be thankfull for any help.