The truth about DDC's

[Waterlogged]

OK, so it's time for the much hyped and anticipated results of my somewhat "extensive" testing of the various DDC's on the market and how they compare to the older DDC-2. There is even a surprise guest in the test results and the only reason I tested it was because I was genuinely curious about it.

Now, before I show the results, I'll go on the record and say that these results are not to be taken as gospel as the methods I employed are not the same as those used by Martinm210 or skinnee (or even Vapor IIRC) but, they are pretty decent and good enough to give a realistic idea of what you can expect. Now that I'm done with the disclaimer, lets get to the testing methods and then the results.

Testing methods:

For flow test, I used a Koolance INS-FM17 attached to CPU fan header on an old MoBo and read the results in bios. Results were rounded to the nearest .1 LPM.

For Pressure test, I used an old fuel pressure gauge that reads 0-15PSI (graduated by .2PSI). It was mounted via push-in fitting to a T and then to the res via a valve. The valve on the res was opened and closed several times to confirm the reading taken. Since the gauge is a bit old, I decided to add in the ± you'll see in the results as wiggle room even though the results were easily repeatable to within .1PSI.



For total lift, I used the old tried and true method of tubing going straight up a wall and measuring the distance the water traveled from the end of the barb. Number's were rounded down to the nearest full inch to keep things a little simpler. I will admit that "me judging height by eye" = epic FAIL as the room I tested this in at work was only 24' and not the 30'+ I originally reported. Good thing I didn't need all of the 24'.

For RPM's, pumps were hooked up to a 3.5" Kaze Master and the most prevalent RPM was recorded with ± wiggle room. For those pumps that changed RPM's due to added restriction when the valve was closed during pressure testing, both a min and max number was recorded.

All the tests were repeated for both the 3.25 and DDC-2 with the Petra top for each respective pump. This was done to show the effect after market tops have on the pumps compared to the stock top. For the other models of DDC's not tested with this top, the results for the 3.25 "should" scale similarly as they would use the same top.

Now, for the results.

Stock Top

Pump__________Total head pressure (PSI)__________Total lift (Foot)__________Max Flow (l/m)__________RPM's

3.1 (new PCB)__________5.4 ±.2____________________12' 2"__________________~7.3_____________3840 ±30

3.1 (old PCB)___________5.4 ±.2____________________12' 2"__________________~7.3_____________3900 ±30

3.2___________________6.8 ±.2____________________16' 1"__________________~8.4_____________4530 ±30

3.25__________________9.0 ±.2____________________21' 9"__________________~8.4____________4650-5340 ±30

DDC-2.________________9.8 ±.2____________________23' 4"__________________~8.4____________4530-5340 ±30

Koolance PMP-300._______3.9 ±.2_____________________9' 9"__________________~7.0____________4500-5640 ±30



Petra Top

Pump__________Total head pressure (PSI)__________Total lift (Foot)__________Max Flow (l/m)__________RPM's


3.25__________________7.8 ±.2____________________19' 1"__________________~9.9____________4320-5220 ±30

DDC-2.________________8.2 ±.2____________________20' 10"________________~11.2____________4290-5430 ±30

As for the questions about the revised PCB and being able to do the solder mod, I really wish I knew more about electronics than I do. I pulled apart a new 3.1 and a 3.25 and the only differences I found were about 10/11 of the flat resistors. The micro controller is the same and I tried several different ways to get a number off the FETs but there was just too much conformal coating on them. I tried to scrape it off and the numbers disappeared as well. The following pics are for anyone out there that is more knowledgeable that may pick up on something that I didn't/couldn't.

(Click for larger images)


As for being able to mod the newer PCB, that's unfortunately still up in the air. Personally, I'm going to say it's not possible as these look to possibly be a simple mod away from being PWM controllable from things floating around in the rumor mill.


I tested the Koolance PMP-300 on a whim as I was a little bit curious about how it performed. While not as good as the "main" pumps such as the DDC or D5, it did exhibit qualities that would make it a nice little pump for a separate MOSFET or Chipset loop with a 80mm, 92mm rad or 120mm. It is reasonably quiet (on par to a MCP350/3.1) and as you can tell from the numbers, has more than enough oomph for a small load loop.



Oh. . .and skinnee, I win.