Hi guys, I have posted elsewhere, but I thought it would be of great interest to people searching for a few more degrees cooling or lower noise from their Big Typhoon.
First - the mod - easy as could be:
When you take the fan off the Big Typhoon, you notice two gaps and some wasted space at the corners. Air being what it is, will take the easiest route, and some misses the heat fins completely. So I plugged these two gaps with small bits of foam - 1 x 3 inches does it nicely. No glue, just stuff it in. This forces ALL the air to go through the heat fins - saving 2 degrees!
(showing gap plugged with foam)
Mind you, it saves in proportion to the airflow going through the heatsink, so if you are undervolting you might only see 1C benefit.
My new obsession with getting more cooling to allow more volts has gone well - I saved 10C by switching to the Big Typhoon from the Zalman 7700, 6C by cutting a hole in my case side to duct only fresh air into the CPU, 2-3C by upgrading the fan to a Panaflo High speed, and now 2C with some foam. And 1C from lapping it.
(X2 4200 oc'ed to 2662Mhz at 1.536v at 37C load temps.)
Now I am coming from a background of wanting a powerful overclock yet quiet too! So my machine is now quiet (like 3 hard drives noise) and when it gets over 27C in my room I crank the fans up to lower things about 4C - and the fans are less audible than my room fan cooling me.
My testing shows that swapping the Typhoon fan to more powerful Panaflo 120mm Medium, High and Ultra High goes like this:
55CFM Typhoon stock fan to 69CFM = -0.5C **
69CFM to 103CFM = -2C
103CFM to 114CFM = -2C
**(this data is a bit fluffy - I was making other changes at the time)
But that 2C you save from plugging the holes looks pretty damn good when you compare the decibels needed to do it just via extra fan power.
Hope this is of interest, I have learnt a lot browsing these forums and wish to give something back in return.