I forgot to add...
An "8x for all" tweak will allow you to TRY to do 8x on any media .... getting a usable result is a different matter - ideally you need to evaluate the result by PI/PO measurement.
eg.
http://cdspeed2000.com/go.php3?link=cdspeed30.html
But the Pioneer writers are not supported for measurement, so the best you can measure is only a basic level read error test.
One report for the very cheap Datawrite Red V3 has it as working at 8x in a Pioneer 107 - not even mentioning a speedhack, despite this being 4x media.
PI/PO error rates increased at the end at 4x, a bit more so at 6x, and the 8x zone at 8x was poorer, but all burns were usable - but probably better to be thankful for 6x, rather than pushing it to a poorer 8x
What I gather from reading about Datawrite Red V3 (infosmart), is that this cheap media can give reasonable results IF your drive likes it, whereas the ever popular Ritek G04 dye works well in most drives (comment on the Datawrite Red V3 - if your drive doesn't like Infosmart, go for the Yellow V2 - Ritek dye, instead).
Budget media is a bit of a lottery!