Is my GTT teacher being unfair?

Hello. I'm in 8th grade and all 8th graders have to take a cl called "GTT" which is basically Wood Shop. The teacher refuses to give grades higher than 92% on projects and I got an 88% on my first one. My parents expect A's, not even A-'s, and it'll be really hard to do well enough on the 1 test and 1 crossword we have to offset this. I think it's stupid that he refuses to give out perfects. I screwed up a little on my first project and now I have no chance at an A. In fact, it's almost impossible to get an A because of his cap of 92% on projects, which count for almost all of your grade. I'm getting 99%+ in Honors Geometry, Honors Language, Honors Science, Social Studies, We The People, and Spanish, and I could get screwed out of a 4.0 because of GTT? How can I get this changed??