You need to raise the gpu voltage, not pcie voltage.  You will want a upgrade, but wait till the next batch of cards come out, 980's have already been out for a while and new stuff is expected very soon.  You know something is going on when every 980 card is out of stock on the EVGA website
 
Edit:  Almost forgot, if you start clocking your cards, plug that extra pcie 6pin into the motherboard in the bottom left corner below all the cards.  Best not to let our boards have a meltdown trying to supply the extra power through the 24pin.  The instructions leave that small detail out...

No way unless you're running really good chips and have really good water cooling at the least or better yet, LN2.  These fermi's came from a very dark place.  They run very hot and suck lots of power.  

Boxlid
The good news is that even 700 series was a huge jump, so you'll be very impressed with what you get most likely.  I wouldn't bother pushing that card much, they were called Fermi because they were the first to make your board achieve critical mass on the 24pin power connector, causing it to melt   Well not really, but that was the starting of the extra pcie power connector on x58 for that reason 

Well that certainly makes sense. I have a Kilowatt meter on my tower, and if I remove both those 580's and run some  simple graphics card, power is significantly reduced. They are definitely power hungry. I will probably just sell these off, and put whatever I get towards a new graphics card. If those Titan Z's truly dropped down to $1,500.00 I might just get one of those. My plan is to upgrade to 4K monitors along with a graphics card upgrade over the next year.

Hmmm, sounds like a design flaw on the card. Is this maybe why the price dropped all of the sudden? Maybe I will wait for next gen cards to come out. That would be pointless for me to spend that much on a card only, to be limited.

Yup, the Titan series was a Hybrid GPU for renderers who liked to game and didn't want to spend $2k-$3k+ on a Tesla/Quadro and couldn't game.  A lot of folks got confused and thought that is the "Top Of The Line" gaming GPU when it kinda is but isn't. lol  For a straight gamer, the top of the line for Keplers for example was the GTX 780 Ti, hands down and cheaper than a GTX Titan.  There is an exception to those that needed more than 3GBs of Vram for higher resolutions.  Other than that, people misunderstood and over spent but it is their money as they can do whatever they like to.  
 
I would probably wait and see, if you could wait towards the end of 2015 and see what they come out with.  My guess is they will do the same thing they've been doing with the 700 series.  Come out with the 256-bit (GTX 980) now and bring out a beefier 384-bit down the road with more cores and possibly more Vram etc.

corndogg18
Supposedly they were designed to handle a Kilowatt plus when being pushed to their limits. Kingpin made them sing, but lets be real, the clock speeds he achieved might last a day and those cards he used would have more value as a paper weight then a symphony of polygons when hes done with them... ha ha.

Just for some clarity, he got up there close with the Classified/ Classified Ultra which were custom PCB's with a truck load more voltage regulation circuitry.  I got my 580's up to like 950, at around 975 no matter how much voltage I dumped into them with some third party apps, I couldn't get it to stop artifacting, and this was in a cold room with a really hefty water loop keeping the cards at no higher than 44c under HEAVY load.  The card that was confirmed to pull over 1kw was the 780 KPE card.
 
From my own experience, all Fermi's were crazy power hungry, but also while the 580 was a lot more stable FPS wise in games, it tended to be a LOT more picky, my 480 never cared what I did to it, it just worked, my 580's were faster and really smoothed out the low points of FPS drops compared to the 480, but my 580s (2 way SLI, had a total of 4 over the years) were never as stable or resilient as my 480, and my 680's were  a HUGE step forward there too. 
Unless you clock just to see what you can get out of it, I would suggest upgrading at some pint, I think you will be REALLY surprised at the difference in performance.  When I did, I had an X58 FTW3, [link=mailto:930@4.2]930@4.2[/link] and [link=mailto:12gb@1600]12gb@1600[/link] 8-8-8-20 and went from 2 1589 (580 1.5gb Hydro Coppers) to 2 2686 (680, stock clock reference) and just testing out the cards, with only one in, before i put them on water, Crysis2 with DX11  addon and high res texture pack, went from 50 FPS in mild action and 20 in heavy when the RAM bottomed out, to 85 FPS in light action and 55 in heavy.
 
Unless you have a soft spot for those cards ( like I do for my old 8800 Ultra Hydro) I think the best way to get what you are wanting from the card would be a more modern architecture.