CREATE TABLE table_23465864_4 (sat_29_aug VARCHAR2, fri_28_aug VARCHAR2)

What time was achieved on Saturday 29th August by the rider who recorded 25' 01.89 90.438mph on Friday 28th August?
SELECT sat_29_aug FROM table_23465864_4 WHERE fri_28_aug = "25' 01.89 90.438mph"
SELECT "sat_29_aug" FROM "table_23465864_4" WHERE "25' 01.89 90.438mph" = "fri_28_aug"