rc11...do you compete regularly? If so...let me know. I am sure the engine will satisfy your goals. I am toying with the idea of offering another porting scheme for a pipe...for a reasonable charge. These are things you can do when you make your own parts and know them well.
The way it is stock...you will surely see a performace gain on a pipe...but with some more aggressive porting...it will be a bit unreal. As you know...you usually cannot have it all and there are some compromises with crazy porting. These compromises may be outweighed by another 200 rpm though at top end.
I will try with an 18x10 as soon as I get one. Problem is I dont have any planes that use a 10 pitch yet....well...I have an H9 150 Mustang test plane that is almost ready...but I could always throw a prop on an engine and put it on the test stand. I hope it will do an honest 120 mph with the SAP180hp...it does fit in there really easily though without any hacking and the exhaust pipes just protrude slightly from the bottom.
What prop do you use normally?
Yes...the throttle is linear...you will like it. Very little, if any, "recurving" of the throttle is needed to make it absolutely perfect. The carb has an accelerator pump and high speed check valve, as well as the standard, built in walbro pump and regulator...so you can tune the low needle to exactly where it needs to be and still have great throttle response. No need to make the low needle "fat" and gurgly to have great throttle response. This is just another thing that separates the SAP-180HP from others. Its one of those things that...yes of course it costs more, but it is clearly better in many ways. Once modelers start seeing our engines first hand and using them in their planes...I will let them write about everything else...it's far easier for me...and unbiased testimonies are better anyway...