NEC-3100 will only burn DVD-R's at 2.4x

Whats up everyone? I’ve been trying unsuccessfully to flash this NEC-3100 in order to burn DVD-R’s at greater than 2.4x.

I’ve used:
Liggy 2227 beta 8
Maddog 2F8
TDK 2c8
And of course the stock firmware

No matter what I try I wind up with only being able to burn DVD-R’s at 2.4x. I’ve tried using Ritek GO4’s and some cheap Sonic 4x disks. I have a little over 100 DVD-R’s but no DVD+R’s to try out. I used to have a NEC-ND2500a that burned all of those disks at 8x fine. Does anyone have any ideas what I can do to bump up the speed? I don’t want to have to get rid of all these blank disks and buy +'s if I don’t have to. Thanks.