Oh, sorry for not pointing this out but I am a Junior right now. So I'm not in a hurry, I just hope that it does not affect my SLS application.
I didn't know that the Academies superscored ACT scores. I thought that you could only do that with the SAT. If I do in fact have to take it again with writing, I'm afraid that my score will go down. I got a 35 in English last time so any sort of low score on the wriing portion will lower my grade.
First of all, the SLS application doesn't require ACT scores at all. I'm assuming you took (or are taking soon) the PSAT, and those scores should be adequate. My son only submitted his ACT scores from 9th grade, and he hadn't taken the writing and they took them (in addition to his PSAT scores, which were much lower comparably) without question.
Second, on the ACT, the writing portion does NOT affect your English score like it does on the SAT's writing. You still get the same 4 subscores, averaged for the composite, then a separate writing score (on a scale of 2-12). True, there is another "score" that's a combination of your writing and English that kind of forms an extra subscore on your report, but I don't recall my son ever filling that in on an application, nor does it affect your composite.
Finally, just a suggestion that if you buy one of the Princeton guides, they have a way you can take online versions of the writing (for just a couple dollars each) and have them evaluated with comments. Granted this isn't exactly the same, because you have to type instead of write, but it gets you some feedback and a feel for the time and typical prompts. The first time my son took a writing, he got an 8. He did a bunch of the practices and got an 11 and a 10 on the next two tests. The ACT is far easier (in my opinion) to prepare for the writing on - they're looking for a basic format (that any ACT guide can give you) far more than what you say (HOW you write it, not what you write). Takes about 5 minutes to learn, but then you just have to practice to be able to get it in the short amount of time you have. I taught my 8th grader it before he took the test for practice in June (after his brother had taken the previous 2), and he got a 10 on the writing portion, and he is NOT a writer.
If you got a 33 last month without the writing, you certainly have the knowledge to learn the basics of the writing test and get at least an 8 (which is more than acceptable) and probably a 10. Interestingly, your scores are very similar to my son's. He took it in 8th grade and got a 26, 9th grade got a 31, then junior year got a 33 and then finally a 35. The last time he only took it because he was determined to get a 36 on the math and was astounded that his English went up 4 points too. So keep trying - you have nothing to lose! Good luck!