I saw this new chart posted somewhere, haven't tested it myself
EIAS // frames
34 // 11
46 // 10
61 // 9
78 // 8
101 // 7
129 // 6
supposedly the frames can be calculated using
AnimDuration = {(AnimLength * 256) / [AnimSpeed * (AnimRate + SIAS + EIAS - WSM) / 100]} -1
I'm not sure where AnimLength, AnimSpeed and AnimRate come from though, and I guess its different for each attack.
So lets assume this little chart is correct then we can do some calculations
ias needed = ((120*(EIAS - Skill_IAS + WSM))/(120-(EIAS - Skill_IAS + WSM))
assuming EIAS = 120 * IASItem / (120 + IASItem) then we have (rounding all calculations up to the nearest whole number):
120 * (78-0-30)/(120-(78-0-30)) = 80% ias to get 8 fpa trap laying speed. (assuming no bos and gts)
120 * (101-0-30)/(120-(101-0-30)) = 174% ias to get 7 fpa trap laying speed. (assuming no bos and gts)
120 * (78-52-30)/(120-(78-52-30)) = -3.87 so 0% ias to get 8 fpa trap laying speed. (assuming lvl 19 bos and gts)
120 * (101-52-30)/(120-(101-52-30)) = 23% ias to get 7 fpa trap laying speed. (assuming lvl 19 bos and gts)
120 * (129-52-30)/(120-(129-52-30)) = 78% ias to get 6 fpa trap laying speed. (assuming lvl 19 bos and gts)
now lets say we wsm bug sq with gt so our wsm becomes -45 and we have:
120 * (78-0-45)/(120-(78-0-45)) = 46% ias to get 8 fpa trap laying speed. (assuming no bos and wsm bug)
120 * (101-0-45)/(120-(101-0-45)) = 105% ias to get 7 fpa trap laying speed. (assuming no bos and wsm bug)
120 * (78-52-45)/(120-(78-52-45)) = -16.4 so 0% ias to get 8 fpa trap laying speed. (assuming lvl 19 bos and wsm bug)
120 * (101-52-45)/(120-(101-52-45)) = 5% ias to get 7 fpa trap laying speed. (assuming lvl 19 bos and wsm bug)
120 * (129-52-45)/(120-(129-52-45)) = 44% ias to get 6 fpa trap laying speed. (assuming lvl 19 bos and wsm bug)