The two drivers had a confrontation at last week's NASCAR Cup at Pocono after slamming into each other on the final lap. Johnson accused Busch of trying to run him down, while Busch contended Johnson made the first move. Busch finished third, one spot ahead of Johnson.
Johnson said at a news conference at Watkins Glen International on Friday that he was angered by Busch's remarks after their argument in the pits.
"When he got out of the car, we're talking, and the crowd started to build and his bravery started to build," Johnson said. "I walk away and he keeps talking. That's the part that frustrates me. That's when you saw me engage like that. If you're going to say something, say it to a man's face.
"I don't know about you, but that really makes me mad. He just started running his mouth."
Johnson said there were two parts to the altercation — what happened on the track and then on pit road.
"We come off turn one and Kurt gets to me side drafting," Johnson said. "I tried to break the side draft, and from there he felt it was necessary to run into the side of my car and tear my car up. I was mad at that point. I never touched him."
It wasn't the first dustup between the five-time Cup champion and Busch.
Ever since Busch chanted "anyone but the 48" after Johnson drove his Hendrick Motorsports Chevy past Busch to win at Bristol last season, the two have had issues.
When Busch bumped Johnson out of the way to take the lead in the closing laps at New Hampshire in June a year ago, Johnson caught Busch, put a little bump on his Penske Racing Dodge and slipped his No. 48 underneath with two laps to go and won.
"I don't want people to think, 'Oh, I can knock the 48 out of the way because he's not going to wreck me,'" Johnson said after the race.
Then at Pocono it got worse when Johnson caused a stunning late-race crash that collected Elliott Sadler, Clint Bowyer and Busch. Replays showed the 48 appearing to hit Busch from behind. Busch's car swerved in front of Bowyer's Chevy before slipping sideways into the infield grass and smashing into the infield barrier.
Busch walked away, the race was halted for 20-plus minutes while workers cleaned up extensive debris and welded the barrier back together. After getting checked out by medics, Busch pointed blame straight at No. 48.
"I wrecked on the straightaway. Jimmie Johnson drove straight through us," he said.
Johnson called Busch the next day to talk, and the two said they'd put their problems in the rearview mirror.
The latest still simmers.
"There's no secret about it that there's no love lost between the two of us," Johnson said. "We can deal with it. We have done it. We didn't have wrecked race cars at the end of Pocono. I could have easily gone down into the Tunnel Turn and done something stupid. The stuff on the track, yeah, it makes me mad.
"When you look over the years and what his mouth has done for him — he got my biggest fan (former Cup driver) Jimmy Spencer to punch him," Johnson said. "It's led to issues with the NASCAR officials on pit road. I think we all tune in weekly and wonder, 'What's he going to say to his crew guys?'
"Look at what he said about Roger Penske, his car owner. That aspect is the part that really got me mad. At the end of the day, I'm not going to let him run his mouth."
Busch has a bad habit of doing that, even though he's worked hard to improve his image since he won the Cup title in 2004. That's when he beat Johnson by just eight points in the closest championship in series history.
During the night race at Richmond in late April, Busch, angry because his car wasn't competitive, yelled at his crew during the early portion of the race and blamed Penske Racing's shortcomings on technical director Tom German over a radio frequency available to the public.
Busch has since rebounded and sits a solid fourth in the Cup standings, two spots behind Johnson, as the Chase for the Sprint Cup championship looms in five races.
"Issues that develop through the course of the year, some last longer," Johnson said. "You've just got to take it as it is. The way that things are handled on the track sets the tone. If it turns into wrecking cars, man, that's the worst situation you can have going into the Chase."
Busch will hold his press conference on Saturday, and he'll likely will be asked about the situation with Johnson.
At least one driver likes the prospect of an ongoing feud.
"If it carries over for those guys all throughout the last 15 races of the year, it wouldn't bother me a bit," said younger brother Kyle Busch, who is third in the standings. "But I certainly wouldn't want any part of it.
"It's something that they've kind of had going on for the past few years, I guess. Whatever it is, it's not my beef, not my problem."