Aluminum rods are permanently stretched every time they're run near their limit. Steel rods recover to some extent, last much longer.
It's not design or quality control, it's metallurgy.
Did you read the article from the GRP guy? For bracket racing they claim 1000s of runs, top fuel 8. And he said they were compressed not stretched. I’m sure they went to school and do all kinds of testing to improve their products.
