Seriously, 1:34.x is a great time for new player. Realistically ~1:33.3 is the fastest you'll see in a race without bumpdrafting or other trickery and there's only a handful of players that can pull it off, provided they get a perfect lap.
Having said that, I would suggest to look into two things:
-Make sure throttle cut on upshift is turned off (options/player)
-Exit speeds. Since the XFG has so little power, it's very important to carry a lot of speed onto the straights, especially in the uphill sections. Exit the S 2-3mph too slow and you lose half a second. Do the same in the last corner and you're at a full second already, plus it'll hurt the first sector of the next lap.
If you want to compare different lines through a corner or turn-in techniques, I would suggest checking your speedo at certain points on the straights after the corner. At Blackwood you can use the sector marks and the finish line for example.
Just for reference, on a very good lap I usually see 140km/h at the finish line, 165 just before braking for turn 1, 155-156 at the first sector mark, 178 just before the bridge, 125 across the second sector mark and 112-113 through the last turn.
If you really wanna get technical it might be a good idea to use AnalyzeForSpeed (
http://www.ctd-racing.com/AFS/) to compare your lines/speeds to others.