The sad thing is there are already many well-researched strategies for improving the success of all students in calculus and significantly reducing any gaps between student groups.

Things like:

* Teaching the math in context instead of abstractly. See https://engineering-computer-science.wright.edu/research/eng...

* Give students opportunities to learn from one another in groups, using techniques like peer instruction, peer-assisted reflection, peer-led team learning, supplemental instruction, etc. https://link.springer.com/article/10.1007/s40753-015-0005-y

* Use adaptive learning tools that help personalize the learning, give students extensive practice, and let them go at their own pace. See ALEKS or MyMathLab, for example.

* Teach students how to learn, how to study, how to manage their time, etc. See for example this class https://researchnews.osu.edu/archive/lrngclas.htm or this lesson https://styluspub.presswarehouse.com/Titles/TeachStudentsHow...

* Certified training for tutors, peer mentors, teaching assistants, and the like http://serc.carleton.edu/sp/library/learning_assistants/inde... http://www.cirtl.net/

* Train the faculty on how to teach better with active learning instead of just lecturing http://www.sciencemag.org/news/2014/05/lectures-arent-just-b...

There was a national study even of what the best calculus programs do: https://launchings.blogspot.com/2014/01/maa-calculus-study-s...