Both motors "ripped" (for about 45 seconds) with the extra cell - just wish it would work. The plane is designed to be a "park flyer" so i can't expect it to be a screamer; I just wanted a little more speed for the passes. One other thing I thought about trying: GWS makes a 5-blade EDF-50 that would produce more thrust. I have heard of others using this unit with great results. They stated that it didn't fly faster but with more authority. The only problem is that I can't find anyone who sells them. Everyone I have tried is out of stock. I also have heard that GWS makes a 50H version of the fan unit that handles 10.8 volts instead of the 7.2 volts with the stock unit. I can't seemed to find these either. Have you even compared the stats of these motors and fan units from the box and the GWS web site? The numbers don't match - very frustrating to make a decision with conflicting data.