The Corsair Obsidian 800D is an amazing and massive case, but even in its current state, it doesn't really have enough room for a second radiator. I wanted my new build to have two separate liquid cooling loops, so I had to find a way to mount a second radiator somewhere in the case.
After pouring over pictures online, I decided that the best way to accommodate a second radiator was to remove the lower hard drive cage and make room for the rad down there. I personally only need room for 4 hard drives, so the 4 hot swap bays accommodate me perfectly, and I have no need for the lover hard drive cage. Once I received my case, I double checked my measurements and got to work on the mod.
Before we go any further it is important to note the this will affect the warranty on the case. Redbeard said; "Obviously we’d still replace things like fans that were not affected by the mod, but the fit and finish, door panels, anything that might be affected by a structural change would be unwarrantied."
I will be posting medium size pictures to this thread. If anyone would like to see any of these pictures in greater detail / larger size, head over to the following link:
800D Bottom Rad Mod Photo Set
With that said and the "Disclaimer" out of the way, here we go.
Tool wise you will need a drill, and a Dremel (Rotary Tool) to accomplish this mod. I also recommend a Rivet Gun/Tool, but its not absolutely necessary.
First you need to pop off the front panel to expose the rivets in the front of the case. The six (6) rivets shown in the picture below are the first to go. I found that a 1/8" drill bit right through the middle of the rivets works perfectly to remove them.
The front and back pieces of the rivets.
There are two (2) brackets behind the lower hard drive cage that must also be removed. Luckily they just require a screwdriver.
This is where things get tricky. The last two (2) rivets that have to be removed are located towards the back of the hard drive cage. There is not much space to maneuver, so I had to use a combination of a cutting disk and grinding stone on my Dremel to remove them. With these last rivets removed, you can now pull the hard drive cage out of the case.
You will now need to replace two (2) of the rivets we previously removed. They had to go in order to get some give when pulling out the hard drive cage, but with the cage removed you need to put them back in for structural stability. If you don't have a rivet gun, small machine screws and a nut on the back would work, but you will have to figure out what size on your own.
Hard drive cage removed, and necessary rivets have been replaced. Now we move onto cutting a larger intake hole for the radiator.
I used a HardWare Labs GTX240 for my radiator. Any 120x2 fan radiator should work just fine. The idea is to have the fans mounted on top of the radiator where they would be pulling air from the bottom of the case up through the radiator and expelling it into the other cooling zones of the case.
There are many ways one could measure out the area for the intake hole and the mounting holes, but I found using an A.C. Ryan Rad Grill was the easiest. Trace out the area for the intake cut and make note of where the mounting holes need to go.
I messed up here and made the intake too large, therefore eliminating the two mounting holes on the right. Luckily it was an easy fix as you will see later in the thread.
FYI... using a rotary tool on a steel case is not an easy task. I ate through 3 cutting discs by the time I was done. But it did the job, while making a mess of the surrounding area. Be sure to wear eye protection on this step. Tiny metal shards flying at high speeds towards your eyes should be avoided.
Done with the hard stuff. Now to attach the radiator and fans. You will also note that I removed the fan that was attached to the metal separating the PSU zone from the Mothebroard zone. It will be reattached, but in a different position as will be shown later.
I placed the Rad Grill in between the case and the radiator. I also installed some 1/4" thick weather stripping material I found at the local hardware store. It is sticky on one side and makes for a gasket of sorts between the case, radiator, and fans.
Here you can see everything secured together. The gray you may notice comes from the weather stripping material. It can be spray-painted before application if you want it to be black. Since I cut the intake a bit to large near the right corners, I had to use some washers in order to properly secure the back of the radiator to the case. I also used the same material on the rails the support the PSU towards the back of the case which can be seen two pictures down.
This picture shows that even after the mod, a large PSU like the Corsair HX1000 has plenty of room to run your cables. I will put the cable management back-plate back onto the case once I have run my tubing to the bottom radiator. The fan has also been re-attached to the metal separator in the case above the radiator.
This should give you an idea of what airflow will be like with this mod.
Well, thats it. Thanks for taking a look and feel free to shoot me a question if you get stuck somewhere.
Update - 10/03/09
I wanted to post two additional pictures that will better enhance this mod.
Here is a 140mm magnetic fan filter that goes perfectly over the new intake cut-out area. Sticks right to the steel case, and is easily cleaned and removed. I tested before and after, and there is little to no airflow restriction while using it.
If you look closely, you will see that I added a wood dowel to better support the metal divider between the PSU & Motherboard area. Cut to fit and Spray-Painted black.
Click to View Larger Image
If you would like to see the full build log for this system, head over here:
Corsair 800D Liquid Cooled Dual Loop System
Thanks for looking.