Can I invest all my business profit into a 401K?

Hey guys, I'm doing some tax planning and may have found a good way to shield myself from a considerable amount of tax. Here are some details;

I work a full time W2 job and also have a small side business (sole owner LLC) that I operate on some weekends. Problem I have is that by time I pay all the tax on my profit (40%) I don't really think its worth my time so I have always reinvested all the profit in equipment. I think I should have all the equipment I need now so I am considering opening a self directed traditional IRA and just investing all of the profits in that account.

My thought is that I would only contribute up to the match on my 401k program at the W2 job and backfill the rest up to the IRS (457?) limit in my IRA.

Am I missing something or is this plausible?