well after heat issues with a thunderpower 7.5 and a lrp octawind 6.5 my friend let me use a hacker 6.5 just to see, well the results speek for themselves it still had the same speed with a smoother powerband and after 10 min it came off the track at 135 and that is with setting record lap times at my track so I was pushing it hard. Cant explain it but it worked lol.