How can I change Chrome's default search engine from the regional one to google.com without losing search suggestions?

Here's one way to make search suggestions work, if you have a URL for fetching them.

1. Set the default search engine as you normally would, then exit Chrome completely

2. Open the Preferences file in your user profile

3. Look for default_search_provider_data

4. Under it, look for template_url_data

5. Under it, look for suggestions_url, or create it if it does not exist. Set it to a working URL, such as

   "suggestions_url": "https://clients1.google.com/complete/search?client=chrome&hl={language}&q={searchTerms}"
   

   (Don't forget to add a comma at the end if there is another element following it.)

6. Also set suggestions_url_post_params as appropriate (it can be simply "" for the above URL).