The Toms effect is a reduction in fluid flow energy losses by additives that reduce turbulent friction. The dynamics of the transformation of the Toms effect is presented for pressure turbulent flows of aqueous solutions of polyoxyethylene WSR Coagulant (Union Carbide Corp.) (POE) with a chain structure of molecules and a molecular weight of ≈6.5 ⋅ 106 through a pipe with a sharp narrowing from a diameter of D = 20.95 mm to d = 5.81 mm. Solutions with mass concentrations of C = 1–100 ppm were studied. At C ≤ 50 ppm, a higher value of C corresponded to a greater decrease in the hydraulic resistance of the pipes, which for d = 5.81 mm at C = 50 ppm and Re= 2 ⋅ 104 reached 70%. POE solutions, flowing along a sharp narrowing of the pipe, reduced the resistance of the pipe with a diameter of D. The resistance of the sharp narrowing of the pipe increased. After the latter, flowing in a pipe with d = 5.81 mm, POE solutions restored their ability to reduce hydraulic resistance. The distance of complete restoration of the hydrodynamic effectiveness of the studied POE solutions depended on their concentration, Reynolds criterion Re, and pipe diameter. For С = 5 ppm at Re= 5 ⋅ 103 this distance was 50d, and at Re= 2 ⋅ 104 it increased to 100d. At С = 50 ppm and Re = 104, the effect was restored at a distance of 120d behind the pipe narrowing.