try with -w 256 --lookup-gap 2 and --thread-concurrency 6144, 5120 or 4096
then try cranking up the intensity. 16-20 tend to give the highest rates, but lag the machine considerably more than 14-15
well some more toying with it i used the settings below and the hashrate tripled now its going at 310Kh/s but it get incredibly hot im talking 82c so i have to shut it down using a radeon 5830
setx GPU_MAX_ALLOC_PERCENT 100
cgminer.exe --scrypt -o stratum+tcp://stratum.wemineltc.com:3333 -u xxxxx -p 12345 -I 17 -w 256 -g 1 --gpu-engine 950 --gpu-memclock 1250 --thread-concurrency 5600
I always found setting the fan with a program outside of cgminer worked best for me
Try EVGA precision or MSI afterburner. Doesnt matter what make your card is.