ORIGINAL: cmoulder
ORIGINAL: tele1974
So the Focus II would be too big for the Syssa and the Focus Sport might be a better choice.
No, the Focus II is a good match as long as the final package weighs in at about 10.5 lbs. The SAP would be way too big for a Focus Sport (which is no longer being sold as far as I know).
But it took some effort to keep the weight of the Focus II around 10.5 lbs. The big factors that kept the weight down were getting rid of the fiberglass pipe tunnel (which won't fit the ES pipe anyway) and making a balsa-lined pipe tunnel (see page 12 this thread), using much lighter control horns and linkages than the stock ones, using CF landing gear and wing tube, using the Syssa Ultra IBEC (Tech-Aero) and the Tech-Aero failsafe switch/reg.
[link=http://www.rcuniverse.com/forum/fb.asp?m=9794144]Post #1071[/link] of this thread contains the cookbook list compiled by Matt and me (with contributions from several others) for the SAP in a pattern application. I have close to a couple hundred flights on mine and it is still working well.
Agree with Bob. My Temptress airframe is similar to a FocusII in shape (drag). SAP has no problem in my set up....I don't have as many flights as Bob on my set-up but I have enough to know that it flies Temptress pretty much the same as glow 2 strokes (I've run Temptress with OS140RX, Webra 145 and 160 and Mintor 170).
It does things differently than something powered by a YS170 or electric. Ed listed the main difference in his post. We have said over and over the YS170 is no comparison for the SAP. If you want YS170 performance, there's only one way to get that. I hope people have gotten that much from these 40 odd pages of postings. I've tried to be as truthful and forthcoming as I could be with the findings
As stated many times now, the SAP is a 2 stroke sport engine adapted to pattern use. It is designed to rev up so it should be propped accordingly. The 17x12 apc is the "largest" prop we can run effectively in a Pattern application (Largest in quotes because the engine turns larger diameters but needs lower pitch, which is of little use in pattern).
Simply stretching the pipe doesn't get you more mid range torque as it does with glow 2 strokes. It's a CDI set-up which doesn't need mixture and pipe length to establish ignition timing as does a glow 2 stroke.
To me, *powerplant offerings for pattern* is about options. The SAP is an option that did not exist 7 months ago. It offers 2meter pattern flying on a budget. Maybe, at the end of the day, if one wants to fly a lot and doesn't want to break the bank, this is the best approach. Inexpensive to own and operate compared to all the other offerings. The caveat is that it will not suit every flying style desired. Could it win? In the lower classes, definitely. In Masters and F3A, it may not, at least not in my hands (he, he, he)