Knoxville first tweeted about Dunn, then made comments at a private memorial last Wednesday, but this latest blog post marks the most open he has been to the public.
I felt 34 percent funnier when I was with Ryan, but I guess everyone did, Knoxville wrote.
He had such a hair-trigger laugh reflex. He lived his life wanting to laugh and wanting you to laugh with him. He would cackle really f--king loud, too, and it wasn't uncommon that he would fall over from it. Sometimes I would fall with him because his spirit was very contagious.
Shortly after the news broke, sympathy from fans and several stars pour out over the web and in public forums, with Knoxville also tweeting:
Today I lost my brother Ryan Dunn. My heart goes out to his family and his beloved Angie. RIP Ryan , I love you buddy
Alcohol is suspected to have played a part in the Monday death. Dunn tweeted a photo of himself and another man drinking at Barnaby's of America's bar just hours prior.
The Chester County coroner listed blunt force trauma and thermal trauma as the official causes of death for both men.
Knoxville admitted that he cried a lot knowing that Dunn's son and unborn daughter will not get a chance to know their father well.
I'm starting to ramble now, just like I did at the memorial, so I'll stop, he concluded. You'll have to excuse me, I'm just very sad because I lost my brother and my world got about 134 percent less funny. I don't know what else to say right now, so I will close with I love you, Ryan. I have a lot of emotions swirling, but I want you to know I love you so very much.
A preliminary examination of the crash site suggested that Dunn's Porsche might have been traveling more than 100 mph in the 55 mph zone when it jumped a guardrail and struck a tree and burst into flames.
Toxicology results showed that Dunn had a 0.196 blood alcohol level he had at the time of the crash, more than twice the legal limit.