Stiffens the sidewall to help deal with tire shake. The downside is that it diminishes the tire's ability to expand, cutting back on trap speed a bit.
Elite claims it's a safer design and on the surface it appears that's correct, but no changes in that area can be made without NHRA approval even if they're safer and don't provide an unfair advantage. They have to go through the process.
What I don't understand is that Elite's cars may be down a bit on power due to the change back to VP fuel but they've never had out-of-the-gate problems other than you'd normally see. This season, slow 60 foots, slow RTs and tire shake are the norm with Erica's car, not the exception. She didn't suddenly turn into a poor driver. #10 in points, now #14 with the penalty. Some say it's on account of the absence of CC Mark Ingersoll. Maybe it is.