I made my own mod last weekend using a 1200 and 1 nitro prop (1.25" with 1.5" PVC). I planned on using dual nitros, but broke one. Anyway, I have a few comments and questions.
I made the mod almost exactly like dhnguyen's latest version. I tested it right next to a Seio 1100 I had in the tank so I could put my hand in front of the maxi, then the Seio so I could directly compare the feel. The mod had a little less then the 1100. I then took off the guard I made and run it with just the bare prop. The flow was more than the 1100 and felt like the Seio 1500 I had in my other tank, if not stronger.
So, I figured my intake slots were not big enough or had enough of them. So for testing purposes, I cut out all the slots which left two BIG areas cut out. This should let in all the water the prop needs. Well, not much more flow was achieved. The guard still cut back quite a bit of flow. The cross brace I used also seemed to create a void in the flow pattern. I dremeled it down so it was very skinny, and it still disturbed the flow a little.
One other thing I was wondering was the length between the end of the prop and the end of the guard. I had about 3/4". From all my testing, Im wondering if there should be less space between the prop and end of the guard. Im thinking the less you have, the better and the extra length disturbes the flow pattern.
So, Im curious as to the design of the guard. I think the crucial part of the mod is the guard design. In my testing, the guard effects the flow greatly. Also, the pump had a lot of problems restarting on its own. I had to manually pull on the impellar to get it to spin. I paid close detail to haveing the impellar magnet assembly and prop aligned up and spinning freely on the carbon rod as well as lining up the hole on the cross brace. The pump had zero vibration or noise. However, it didnt like being restarted which was a major downpoint.
