Which model Corsair RAM is it. Big differences between vanilla, vengence models and dominator models (even differences between some sub-brands). Also, what speed and voltage is it labeled for?
Unfortunately there is no good answer for your question even with the above info. RAM is notoriously fickle and what works for one pair may or may not work for another.
In general, best OC will be achieved at 1.65V (absolute maximum), then keeping stock timings and bumping up the RAM speed until it doesn't boot. Then return to stock speed and try the same thing lowering the timings instead until you get something that doesn't boot. Then use this chart to compare which is fastest in your case...
My guess is that if you keep stock speed and bump up the voltage then you should be able to hit around 7-8-8-22 or so. Fiddle around with 1T vs 2T also, but more than likely you'll be stuck with 2T as DDR3 just doesn't seem to like running at 1T in my experience. Keep in mind (see chart) that this isn't really getting you a whole lot, especially in terms of real world performance. The memory OC ship sailed along with the dissapearance of DDR2 a couple years back. It just doesn't matter anymore.
Uh oh. Valueselect RAM. What I said above may still be about right, but more than likely its going to be something like 8-8-8-24 2T @ 1600MHz, 1.65V. That's a best guess since that RAM isn't a "performance oriented" model.
Try the faster timings and bump down to 1333MHz. Keep in mind that the RAM you have is plain jane vanilla stuff and isn't really meant for overclocking. That said, don't worry if you don't see big results because even if you did it wouldn't mean anything from a real world system performance standpoint. Memory overclocking just doesn't yield much in the way of performance these days.
CAS 5 at 1066MHz maybe....He didn't get 5-5-5-18 at no 1600 MHz on some valueselect CAS 9...I call BS if the OP says its running at 1333 or 1600 at CAS 5.....As I stated before no way in hades
BTW...CAS 9 @ 1600 MHz is plenty fast...CAS 7 @ 1333 MHz is roughly the equivilent of CAS 9 @ 1600 MHz ....I run 7-9-8-24-40-1T @ 1.61v --->1600 MHz on CAS 9 @ 1600 MHz RAM yet my RAM was made to OC...So just be happy with CAS 9 @ 1600 MHz with that RAM you have