I hate to break it to you, but you have almost no chance of getting into MIT the way things stand right now. I do some private tutoring for ACT and math and had a really exceptional client apply to MIT this year. We got his ACT up to a 34 and his GPA was 4.0 (unweighted, #1 out of 500 class rank). His academics included an IB diploma and 8 APs. Extracurriculars included a top 10 finish in a high school engineering competition, incredible community service (thousands of hours, president of a service club that he grew from average size to the largest in the state), awards for being NASA competition finalist, state championships in each of technology, business, debate, and quiz bowl competitions, and he was a student ambassador to Taiwan. Oh, and he did high level academic research for 4 years, and got a letter of recommendation from a respected engineering professor that said he was working at the level of a new graduate student. His academics and extracurriculars are vastly better than yours and his only downsides were a lack of sports, and, perhaps, coming off as nothing more than an achievement drone. I looked over his essays and they really helped his personality come through, so I thought they were excellent. He didn't even get wait listed at MIT, Columbia, Caltech, Duke, Stanford, or Harvard.
I don't mean to be a dick, but presuming that you want a good education more than you want people to be nice to you, there's no use in sugarcoating things. If you got into MIT without upping your credentials, you'd be one of the single least qualified student in the incoming class. Of the students that were admitted to MIT last year with an ACT score on their application, 91.9% had an ACT score at least 2 points higher than yours, and your GPA is not helping your case. On top of that, admissions are only getting tougher. My era (class of 2005) was among the last to be able to get into elite schools without almost literal perfection. I went to Johns Hopkins with a slightly better HS GPA and significantly better - but not perfect (except on SAT subject tests) - standardized tests than you, but if I applied today, I am quite sure I'd get rejected, and Hopkins is a lot easier to get into than MIT. You are a good runner and your times are faster than mine, but without an individual state championship, your times are going to mean very little to MIT, where everyone is a rockstar at something. Race does matter - I suspect that my student was looked over, at least in part, due to being Asian - but it doesn't matter enough for MIT to admit someone with a 29 and an unweighted 3.7.
Now, I don't mean to be a total downer. My advice? If you really like MIT, you need to significantly improve your credentials. They will like the improvement you've shown, so don't even consider settling for a 3.85 in your senior year. Work as hard as you can and ensure that you get a 4.0 next year. If you're smart, attitude will mean everything and you can achieve it. Even if you finish your second quarter after you apply, send in a new transcript as an update to demonstrate that you're really working hard and succeeding. Even more importantly, you need to raise that ACT score significantly. Hire a very good private tutor and work with them twice a week for 2-3 months. Your 29 is already much better than most, so don't waste time in a class with a bunch of morons. One-on-one is the way to go for you. Go over test taking strategies and make sure you know everything there is to know about the material on English and Math. Do practice sections for Reading and Science until you can't take it any more, and then do more. Figure out your weaknesses and improve them. This type of work will pay off. It's rare that kids improve more than 3 points, even with pretty diligent work, but I've had a couple students go up by huge margins by working incredibly hard for a few months (22 to 28, 30 to 34, etc). If you can make truly monstrous gains (say, up to a 34 or 35) and keep a 4.0 next year, your odds are frankly still not great, but you'll have a chance. If you don't get in, you can still be proud of the improvements you made, and they will surely help you get into another good school or improve your odds of scholarships at less competitive schools. Good luck.