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RE: SAP 180 (Syssa Performance)
ORIGINAL: cmoulder ORIGINAL: tele1974 I should be just above 8000 with the Xoar 18x10 on a pipe. Is that correct? This engine likes the revs! Find a prop that permits over 9000 rpm and you will be happy. Even for pattern, my engine is quite happy with the 15.5x12W turning 9200 rpm. This is why I think you might end up with an 18x8 (at most! - maybe even a 17x8!!) for IMAC precision, or whatever prop Todd was using in the recent video that produced 22 lbs of thrust![sm=thumbup.gif][sm=thumbup.gif] I tried the smaller prop and could only get maybe 8400 yesterday. It really showed in flight. Downline brakes were lower than anticipated...hard to beat large diameter for brakes. Sound level was not bad...just slightly louder but acceptable. Overall, not as good a match for Temptress as I would have liked...her flying envelope changed more than I wanted. Guys, the point is that for any given plane and environment, one prop/engine combo may work better than another, and may work differently some place else. The best advice I can give is, find something that works for your set-up and stick with it, learning its character in flight. Bob and I have given several choices that work pretty well. It isn't an exhaustive list by any means but are good places to start after some break in. But do a good break in with a light load first. |
RE: SAP 180 (Syssa Performance)
Matt,
I found I needed to lean the engine for the smaller prop. Could be that with the larger props your engine needs to be richer for the bigger loads. I am under 2 turns now (approx 1-7/8, but don't quote me on that!) and the engine is happy as a clam with the warmer temps. I have been extremely careful about changing the H needle since achieving the good performance with the 15.5x12W. Last time I flew it was little over 80 deg and humid, and I tached it at 9160, practically identical to the number at Conyngham when it was high 60's and humid. I will fly later today, when the temps are getting up around 90. I forgot to ask, but what fuel are you using? Were you using the same thing at the Conyngham meet? |
RE: SAP 180 (Syssa Performance)
I tried it again. Alright, I incrementally tested the rpms with the 18x10 from 2 1/4 by 16th's back to 1 7/8th's and I didn't get anything over 7000. It doesn't feel like it's getting on the pipe with that prop if that makes any sense. I am running Sunoco 87 with Stihl Ultra HP at 40:1.
More thoughts: Low end feels good and at about 5500-6000 you can feel it wanting to open up but the rest of the throttle is mush. Sorry about the newbie descriptors. The trouble shooting is much appreciated. |
RE: SAP 180 (Syssa Performance)
1 Attachment(s)
If it is mushy...maybe too rich. tele give a call or email!
Here is the new tuned pipe mount. It's CNC routed and designed to fit the Extreme Flight Extra 300 78". |
RE: SAP 180 (Syssa Performance)
ORIGINAL: tele1974 I tried it again. Alright, I incrementally tested the rpms with the 18x10 from 2 1/4 by 16th's back to 1 7/8th's and I didn't get anything over 7000. It doesn't feel like it's getting on the pipe with that prop if that makes any sense. I am running Sunoco 87 with Stihl Ultra HP at 40:1. More thoughts: Low end feels good and at about 5500-6000 you can feel it wanting to open up but the rest of the throttle is mush. Sorry about the newbie descriptors. The trouble shooting is much appreciated. Did you ever get the correct ID stuff from siliconehose.com?? Definitely something amiss, exhaust or fuel draw. |
RE: SAP 180 (Syssa Performance)
If the pipe has slid back...that could cause it too.
If the pipe moves 3/8", it causes quite a bit of a performance difference. |
RE: SAP 180 (Syssa Performance)
ORIGINAL: cmoulder ORIGINAL: tele1974 I tried it again. Alright, I incrementally tested the rpms with the 18x10 from 2 1/4 by 16th's back to 1 7/8th's and I didn't get anything over 7000. It doesn't feel like it's getting on the pipe with that prop if that makes any sense. I am running Sunoco 87 with Stihl Ultra HP at 40:1. More thoughts: Low end feels good and at about 5500-6000 you can feel it wanting to open up but the rest of the throttle is mush. Sorry about the newbie descriptors. The trouble shooting is much appreciated. Did you ever get the correct ID stuff from siliconehose.com?? Definitely something amiss, exhaust or fuel draw. When I ran really large props, the engine would not come on the pipe at all and only turn in the mid 6s We've run the 18.1x10 apc many runs and know what to expect from that prop. Both of us get similar numbers on that prop. Can you get your hands on one? I think the fuel is fine. |
RE: SAP 180 (Syssa Performance)
ORIGINAL: cmoulder Matt, I found I needed to lean the engine for the smaller prop. Could be that with the larger props your engine needs to be richer for the bigger loads. I am under 2 turns now (approx 1-7/8, but don't quote me on that!) and the engine is happy as a clam with the warmer temps. I have been extremely careful about changing the H needle since achieving the good performance with the 15.5x12W. Last time I flew it was little over 80 deg and humid, and I tached it at 9160, practically identical to the number at Conyngham when it was high 60's and humid. I will fly later today, when the temps are getting up around 90. I forgot to ask, but what fuel are you using? Were you using the same thing at the Conyngham meet? Today was easily the hottest day we've had in NJ....about 93 F and about 60% RH. The engine was quite happy running in these conditions which has got to mean that it is pretty much broken in. Just a liitle over 3 gallons through it. Have used the same mixture of fuel over the last 2 gallons, 90 octane (a 4:1 mix of pump and AV gas) with 50:1 Bel Ray MC-1 full synthetic motoscooter oil (courtesy of Jersey Jim Martin) BTW- I don't notice any jump at all on the pipe at around 3K as I used to get before the set-up was mature. Smooth throttle response which is exactly what we need in pattern. However, with hotter weather I find that I advance the throttle to full on some verticals where I practically never did when weather was in the 50's |
RE: SAP 180 (Syssa Performance)
I have a 15.5x12w on order and I just emailed them to see if they can add the 18.1x10 to the order. I do have the 18x6 Xoar and have been running that one. I will check the RPM's on that one again tomorrow. Initially I was getting around 9500 which I thought was where it should have been for a new motor. I have a feeling something changed since then though.
I am using the turbo tube and a 1" long piece of .875 aluminum. I recently changed my pipe mount and I checked to see that it hadn't separated. |
RE: SAP 180 (Syssa Performance)
ORIGINAL: tele1974 I have a 15.5x12w on order and I just emailed them to see if they can add the 18.1x10 to the order. I do have the 18x6 Xoar and have been running that one. I will check the RPM's on that one again tomorrow. Initially I was getting around 9500 which I thought was where it should have been for a new motor. I have a feeling something changed since then though. I am using the turbo tube and a 1'' long piece of .875 aluminum. I recently changed my pipe mount and I checked to see that it hadn't separated. The extra 1 - 1.5 lbs in weight and the increase in airframe drag of the Extra are going to demand a lower pitched prop for more thrust and less airspeed. The 15.5x12W that I have been very happy with is powering and older design narrow-body pattern plane that is quite slippery by current standards. As I mentioned earlier, it makes about 15 lbs of thrust and so we are pretty safe in assuming that it won't work well for IMAC. In fact, it might not work well for a current wide-body pattern ship, as Arch Stafford (rcpattern) has observed. If you aren't already using the buttonhead screws on the pipe and header, do so because they really do provide peace of mind where coupler slippage is concerned. I've got about 50-60 flights on mine with the turbo hose and the buttonhead screws and there hasn't been one micron of slippage. |
RE: SAP 180 (Syssa Performance)
Yes no question...the carb must be set rich enough to run the bigger props. My HS needle is juuuuust slightly more open than 2 turns. It turns the 17x12 apc (and my 17 3/8 x 12 hybrid) with no sag anywhere in the envelope and gives excellent throttle and speed management. Downlines are YS 4 stroke or electric like which is exactly what I wanted. Significant improvement over the Webras I've run in Temptress. Today was easily the hottest day we've had in NJ....about 93 F and about 60% RH. The engine was quite happy running in these conditions which has got to mean that it is pretty much broken in. Just a liitle over 3 gallons through it. Have used the same mixture of fuel over the last 2 gallons, 90 octane (a 4:1 mix of pump and AV gas) with 50:1 Bel Ray MC-1 full synthetic motoscooter oil (courtesy of Jersey Jim Martin) BTW- I don't notice any jump at all on the pipe at around 3K as I used to get before the set-up was mature. Smooth throttle response which is exactly what we need in pattern. However, with hotter weather I find that I advance the throttle to full on some verticals where I practically never did when weather was in the 50's _____________________________ Regards, MattK It will be interesting to see how the engine works with a modern design widebody ship. I'm glad you're experimenting with the more exotic fuel brews and props because we may need them! |
RE: SAP 180 (Syssa Performance)
The throttle curve that seems to work pretty well right now is a very slight reverse S. Almost a straight line with slight increased rate at the first 2 points of a 5 point curve. The rest is pretty much straight.
I needed faster pick up at the bottom but from mid to full, it's practically linear. |
RE: SAP 180 (Syssa Performance)
ORIGINAL: cmoulder If you aren't already using the buttonhead screws on the pipe and header, do so because they really do provide peace of mind where coupler slippage is concerned. I've got about 50-60 flights on mine with the turbo hose and the buttonhead screws and there hasn't been one micron of slippage. Ed Alt recommended a 50% reduced Simple Green cleaner solution for gasoline powered stuff and this works great in cutting the oil residue. |
RE: SAP 180 (Syssa Performance)
ORIGINAL: MTK The throttle curve that seems to work pretty well right now is a very slight reverse S. Almost a straight line with slight increased rate at the first 2 points of a 5 point curve. The rest is pretty much straight. I needed faster pick up at the bottom but from mid to full, it's practically linear. But wouldn't you know it, I did a new search of RCU this morning and recently someone had suggested plugging throttle into Ch 8 and using the Throttle-Needle curve, and I tried it. After reversing the servo direction, it works like a champ... just need to tweak it before flying next time. |
RE: SAP 180 (Syssa Performance)
ORIGINAL: tele1974 I have a 15.5x12w on order and I just emailed them to see if they can add the 18.1x10 to the order. I do have the 18x6 Xoar and have been running that one. I will check the RPM's on that one again tomorrow. Initially I was getting around 9500 which I thought was where it should have been for a new motor. I have a feeling something changed since then though. I am using the turbo tube and a 1'' long piece of .875 aluminum. I recently changed my pipe mount and I checked to see that it hadn't separated. Also check throttle linkage and end points, trim, sub-trim... sometimes it's something simple like that! Just fiddling with mine this morning got me thinking about that. |
RE: SAP 180 (Syssa Performance)
ORIGINAL: cmoulder It will be interesting to see how the engine works with a modern design widebody ship. I'm glad you're experimenting with the more exotic fuel brews and props because we may need them! It also has a much larger wing (about 15%) than the current designs. I expect the model to make weight, probably around 10 1/2 lbs as my Temptress is. I don't expect any problems with the SAP hauling this model around but has yet to be seen. I really don't want to get a YS for this thing. One thing certain, if the SAP works with this large a plane it will work with anything else we currently fly. I will post results when I get them |
RE: SAP 180 (Syssa Performance)
At this point I am starting to think I might build a kit as a home for my second SAP 180, a BM vf3 or perhaps Evo Pentathlon.
The Evo kit price is very good, but looking at the website construction photos I can already see that it would have to be modified for the pipe, which I would want to be fully enclosed. There is a build thread which I will have to read through. Surely somebody has had to do this by now. Also, the fuse is a pretty simple box construction, and I think I could figure out how to do the sheeting on the foam core wings and stabs. |
RE: SAP 180 (Syssa Performance)
I found this interesting article on oils and mixtures versus carbon build up in one website. I hope it comes through okay
http://www.rcaer.com/userfiles/file/...%20Summary.pdf |
RE: SAP 180 (Syssa Performance)
ORIGINAL: MTK I found this interesting article on oils and mixtures versus carbon build up in one website. I hope it comes through okay http://www.rcaer.com/userfiles/file/...%20Summary.pdf I have run Pennzoil Air-Cooled 32:1, Amsoil Dominator 50:1 and now AMSoil Saber pro 85:1 in various gassers and they all seem to work well. I've never had a fouled plug so maybe I am doing something wrong!:D Seems to me guys are getting pretty good results on just about any 2-stroke oil, dino or syn, so maybe it isn't all that critical, except perhaps the initial breaking in period with dino oil. HOWEVER, even at that I read an article in either Model Aviation or Model Airplane News within the past couple of years wherein a well-known engine guru suggested break-in with synthetic is OK. He mentioned AMSoil Dominator specifically, because it's formulated for 50:1 ratio. Go figure. That said, I know that a lot of the IMAC cognoscenti swear by Bel-Ray. But Desert Aircraft used to recommend AMSoil Saber pro 100:1 and now they endorse Red Line. Go figure again. I'll stick with the AMSoil because I have a bunch of the little 1.5 oz packets and they are pretty handy. Easier than carrying around a bottle and having to measure. |
RE: SAP 180 (Syssa Performance)
Retested rpm's with the 18x6 Xoar and I got 9350.
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RE: SAP 180 (Syssa Performance)
ORIGINAL: tele1974 Retested rpm's with the 18x6 Xoar and I got 9350. Still haven't seen Todd's super prop, but maybe I missed it in the posts somehow. |
RE: SAP 180 (Syssa Performance)
P.S.
[link=http://www.youtube.com/watch?v=zF3E8cPvwaE]ShhhhhMOKIN![/link]:D The caption says it's a Vess 18.5 x 5.5. Amazing performance for a 30cc engine with a 78-inch wingspan model! |
RE: SAP 180 (Syssa Performance)
Those props are not available or are they?
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RE: SAP 180 (Syssa Performance)
I am getting ready to maiden mine and am working on the throttle curve. My throttle setup is a little non-linear mechanically, so I am compensating for it in the radio (suggestions welcome). I ran it yesterday, and it is so smooth, really quiet, and is scary powerful on the pipe. People forget that the carb on the Syssa is unique (on 30cc R/C engines at least) in that it has an accelerator pump. Once the carb has gas in it, just work the throttle a couple of times and it will start without the choke, and the throttle response is immediate.
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RE: SAP 180 (Syssa Performance)
Not sure.
Seems like a custom special that Robert Vess whipped up for Syssa to test. Only Todd may know about the availability. Looks as if it passed the test! |
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