Did you remove the entire linkwheel? If so, submit a reconsideration request. Be completely honest about creating the linkwheel in the hopes you would rank better. You now realize it was a mistake. Show them a list of all the linkwheel properties. Tell them they have all been removed, and you are now adding unique content daily, and are now promoting the site via video marketing, article marketing, and social media marketing.
I had a site that was sandboxed for 8 months. I couldn't figure out why, but then I realized I had stupidly created some blogs with Link Farm Evolution when I first launched the site. Guess what I did? I deleted all the LFE blogs, and my site was back up 2 weeks later. If I had submitted a reconsideration request right after deleting them I'm sure it would have been back up even sooner.
After getting out of the sandbox for about 2 months I got a little over confident. I dropped $800 getting super mininets created for 8 of my pages. Guess what? As soon as the first mininet was indexed I was sandboxed again. Its been 3 months now. I finally decided to go ahead and delete all the properties in the mininets. Thats over $800 down the drain. But I don't care. I'm confident that after I submit a reconsideration request detailing how stupid I am the site will be back.
I pity the fool who does some Blackhat SEO tactic and waits 8 months to a year for their site to get out of the sandbox. IMHO its always cheaper to cut your losses right away, delete the properties, submit a reconsideration request telling them what you did, and get the site ranking again using Whitehat methods.
Let me know how it turns out for you.