You have all 6 fans lined up togather? Maybe you dident, but its a better idea to spread them out. Another thing, its better to have more exhaust. I dont know what size fans they are, im guessing 80mm fans. I also dont know their CFM. But i suggest you get 2 120mm fans. One intake, Second exhaust. Make sure for 120mm fans, the CFM is around 70-100+. If you wanted to replace those 80mm fans, make sure their CFM is around 40-80+.
The better the CFM, less amount of fans. Equals less case modding.
Finished With TF.