ORIGINAL: speedracerntrixie
More food for thought. Looks like the engines may end up on pretty level playing ground. Deciding factors now are cost of header/pipe between the two and of course SAP gets the winning vote on coustomer service. Still not crazy about the choke setup. Has anyone else brought that up? I much rather have the standard Walbro butterfly choke.
Any ideas how the SAP 180 would turn the APC 19X10 pattern prop on standard muffler?
Is noise the main reason 12 and 13 pitch props are used? I would think it more difficult to maintain constant airspeed with that much pitch. I notice much more downline speed with a 22X10 as opposed to 23x8 on 50cc
BTW at the one pattern contest I did compete in this year, my DA 50 was not really louder then some YS powered models. Then again the only time full throttle is used is verticals with snaps.
Yes some have mentioned it. In practice, with a little thought on its set-up, it's a non-issue. In my latest, the choke was modified from stock configuration and is servo driven
The SAP will turn large diameters with moderate blade area and low pitch in the 19" diameter size. The APC 19x10 is possibly too much prop on muffler, BUT I have not run one so I don't know. I do know that the 18.1x10 pattern prop works very well on a piped SAP. I used that prop for break-in then switched to the 17x12 for pattern work. The 17x12 is the largest load I would run in the heat of Summer. I am currently running a slightly clipped version of the 17x12 (down to 16.5x12) which works exceedingly well. I have run a 16x12 and that works well too but rpm are getting up there and the prop noise got a little louder.
I would say try it and make your own decisions. The competitors are not using the muffler....the ES pipe gives enough boost to increase the load considerably