The got my A123 4s pack and rebuild it to 2x2 vs 4x1. I put it my Newbee and went from 330 watts to 520 watts. I was using 3s TP2100. I love the A123 pack. I hope I cam fix 2 4c A123 packs in aPulse XT. The packs is 52mm x52m x 140mm. I may have to go with 3s packs. I am still look for a Pulse XT so I check if they will fit before I order one.

I'de be more worried about the stab or ailerons fluttering. I'de brace the stab and fin and seal all the control surfacers. My Pulse has an OS46AX and it's fast enough. With it's built up tail surfaces I don't think the Pulse is the best choice to go pushing through the sound barrier. Something like an Ultra StickBridi Kaos would make a nice home for the 55.

So you think the .55 might be a bit to much???

Since you are buying a Pulse (which I heavilly endorse), my heartiest suggestion is to read this:

http://www.rcgroups.com/forums/showthread.php?t=632497

It's a very stout motor. The Pulse would probably be ok if you braced the tail and sealed all the control surfaces. the Pulse is pretty quick just the way it is.

This is with the stock Evo 46 engine........ http://largoflyingclub.com/app06/pulse.wmv

Opooops! wrong link. This is the one with the Pulse strafeing runs.

http://largoflyingclub.com/video/austinpls.wmv

BahamasAir,

I have some ball links you could use on the pushrods which will tighten up the control surfaces. This will help avoid the dreaded flutter. And give you a more solid feel to the sticks.

And you can fly at less than full throttle. At least so I am told. I've done it once or twice.

I think it is a clean plane and should be able to handle the 55. Engine invereted of course so you don't have to carve up the cowl too much.

Well I went ahead and bought a Pulse XT. My two A123 4s 2300 packs fit great. I just sanded the rear battery area former so they could side in and out easier. Once in they fit infront of the former. Now I have ordered the motor etc to finish the build. Then I get to see out the cg works out.
I hope the Power 46 runs on 4s A123 ok as it a little lower voltage than lipos.

I flew my XT today. It has a power 46 motor. Using a 2 4s1p A123 packs and a 14x 8 prop. It flys good but I am only using about 400 watts due to the low voltage of the A123 packs. Five cells would be nice but there is no room. With a all up weight of six lbs that is about 50-60 watts per lb. It is a very nice airplane to fly. Maybe next year if I am rich I will buy a six cell lipo for it. I think I could get more weatts from a power 32 since it set up for 3-4 cell packs and has a higher rpm/volt.

Bob