It's three files you can find here
http://www.gamefront.com/files/user/BadgerFinn
The readme.txt (one of the files) contains full instructions, but the basics is change the settings in antilag.cfg (those are the settings sober mentioned), then drop that file as well as d3d9.dll into your game folder (the one with sh5.exe in it).
You can experiment with different values in the antilag.cfg file, and if it doesn't do anything for you, all you have to do is to simply delete the two files from your game directory and all will be back to the way it was before.
