User blog comment:Thailog/Ep. 206 "Bloodlines" discussion/@comment-77.220.15.130-20120603162051/@comment-4963869-20120603165703

In the comics it explained that Wally wasn't as fast as his uncle because his 'accident' was made with a chemistry set and was a bit more controled, even though it did cause him to end up in the hospital. In fact, for the first few days after the accident, Wally still didn't have any superspeed. So now, even with his superspeed, Wally still isn't as fast as his uncle and he can't vibrate his molecules through solid objects.