Back in 2008 there was a thread on /co/ to identify two angry looking speedster characters from a Nike courage commercial, the name "Rage Racer" was suggested and took off from there.
One day, Rowan Racer encounters a series of extremely unlucky events: loses the lottery by one number, misses the train to work making him late, and his boss gives someone else the promotion. To help pay his bills he decides to donate his body to science, during which something goes wrong with a new energy drink (which tastes like shit) and RR drinks the entire thing getting more pissed off over the taste. He is later told he has less than 12 days to live and this makes him even angrier.
Suddenly, he starts raging, HARD. Veins are appearing all over his body, his muscles tense. A flash of red.
He runs out of the Hospital at mach 2 breaking down walls due to sheer force of momentum. The lack of explanation for why this is happening to him makes him even more enraged and so he decides to take action whenever the universe fucks someone over, or whenever he gets pissed.
Rage Racer's danger signal sets off a tiny robotic arm somewhere in his house that knocks shit on the floor just as he reaches for it to let him know when trouble is brewing.
He is extremely petty and has a very short temper.
Every time something that would only annoy normal people occurres, he rages out. He becomes SUPERRAGED when exposed to things that make normal people violent. For instance:
Rage Racer in his civilian alter-ego is sitting in traffic, on his way to work. He looks tired and bored. He is sitting at the corner, getting ready to turn right onto the interstate, when a giant armored van and several police cars blow past, cutting him off. A vein pops out of his forehead and he struggles to suppress it, knowing that he has a big meeting today that he can't miss. As he sits in traffic raging, someone behind him gets impatient and pulls around him, shouting "C'mon!". This is all it takes. The car explodes in a miniature, localized red mushroom cloud, and Rage Racer takes off. He misses the meeting, of course, and this makes him rage EVEN HARDER.
When Rage Racer goes to sleep, he takes fifty pills and hopes that his dreams will enrage him so much that he'll wake up out of his coma in the morning.
His speed is proportional to his rage: the more rage he feels, the faster he can run.
His costume starts out all black when he's relatively relaxed, he gets red in the face when he's reasonably angry, then, as his rage levels rise, more end more parts of him turn red, and with more red, his speed factor also goes up. Finally when he's all red, he becomes a speed god by tapping into the Rage Force, but in this state he's so fucking angry he nearly shits himself, and for every millisecond of being in that state the risk of dying from a heart attack increases.
Of course, since using his powers could cause him to suffer a heart attack, he doesn't want to be Rage Racer. And whenever anyone asks for his help, it pisses him off because they value their lives more than his. Which makes him rage.
His shoes also get destroyed when he runs, making him even madder.
His arch enemy, Mr. Mellow, uses a special calming gas to commit robberies which also reduces RR's speed if he inhales it.
You better make your face up,
In your favorite disguise,
With your button-down lips,
And your roller blind eyes.
With your empty smile,
And your hungry heart,
Feel the bile rising,
From your guilty past.
With your nerves in tatters,
As the cockleshell shatters,
And the hammers batter,
Down your door,
You better run.