Team Xtreem TRC

Hi guys, I'm running my Team Xtreem DDR2 6400 @ddr2 924 @1:1.
Settings are: 4-4-4-12-23-2T @2.2v. Would lowering TRC slightly
bring any meaningful increase in performance? If so, how much lower?
Also, the highest stable OC on my 4600+ is 2772Mhz @1.475v (air cooling).
Would an increase in chipset voltage help stability or higher CPU OC ?
Thanks, still learning.
Edit; the chipset is heat pipe cooled and in my opinion, is barely acceptable
Any other subtimings that are beneficial?

Never mind on tRC, I should have searched, my apologies.
tRC=tRas+tRP; On my ram it would be 16. Is that too tight
for these sticks at current speed? (4-4-4-12-23-2T)
I'll post the other query to AMD cpu forum.