Need to lower case temp

[maxima88]

I just modified my thermoengine HSF by replacing the stock fan w/ a Delta black label fan (the noise is killing me) and I used
AS2. That lowered my temp from 52-55c to 38-42c while running Prime95 for a few hours. my case temp is around 28-30c.
I removed one of my case covers and my cpu temp dropped to 37c. but the case temp stayed almost the same.
I have 2 ordinary 80mm fans (1 for intake and the other to draw out the hot air.
I'm not overclocking and do not consider water colling an option
(wouln't know how in the first place).
Will 2 Sunon 80mm ultra high speed fans in place of my present case fans solve my problem. there isn't much clutter inside my case.
Any advice would be greatly welcome.
Thanks

[Emericana]

goto www.plycon.com , save your ears, and order a 92mm adapter and get a 56.8cfm Panaflow. onlly 35dba it will be much better than your delta and also will cool better. MUCH MUCH softer. i had the 50cfm delta (it was even louder than the one you have now) and the panaflow gives me the same temps but it saves my ears. The more fans you get the better but if you are not going to overclock, i do not see a problem w/ your current setup, your temps look fine

[maxima88]

Thanks for the advice on the Delta fan noise. Kinda getting used to the noise but my real concern is how to get the same cpu temp as when I have one of my side covers off. That's still 3-5c lower.
Any more suggestions on lowering my case temp.
thanks again.