I have an LG GSA-4163B too. Am currently going through a spindle of TDK 8X DVD+R. The problem with TDK 8X DVD+R discs is that different batches are made by different manufacturers, at least for spindles. They are usually either CMC MAG E01 or RiCOHJPN-R02-03. I have used both. The CMC MAG E01 stuff is not that good. Out of a spindle of 24 (1 still unused), 3 or so ended up as coasters. The CMC MAG E01 TDKs burn at only 8X as well and cannot overspeed to 12X.
I am currently using the RICOHJPN-R02-03 ones and those burn at 12X. Have only used 4 so far but no problems with them. From what I've read in the various posts here though, the quality of burns with RICOHJPN-R02-03 on a LG 4163 is not that good as compared to MCC003 or YUDEN00-T02 media. I have no idea how well that compares with TTG02 though and would like to know as well.
I've noticed TDK 16X DVD+R discs on sale in spindle packs of 25. They don't seem to be very expensive, at least here in Singapore. They might be worth a try.