Ganbatte

lol! I'm too lazy to get into the vitto exhaust business; just wanna buy one good/light one.

Well there's that; anything mechanical with weight constraints will require first design attention, then empirical, iterative test-and-refine cycles. Which we expect to be performed by the manufacturers, rather than the users. But when they fail at the same spot over and over, that tells us that spot needs to be beefed up. When failures are randomly distributed over several points, we can conclude the design is mature.

So that brings to mind a thought: I've found that writing vendors, magazines whatever, esp in a small market like this often triggers results. So is there any person or organization we-all can think of who might be nudged to test (with instrumentation, hopefully) vitto vs skymax exhausts?

Spot on, and should we learn that skymax's exhaust drops power a little and flattens the power curve a bit, that would be an interesting datum, maybe even a selling point. It surely would be nice if mfr's published measured curves, so we'd have some clue about these things. The worrisome possibility would be that they're good at titanium fabrication, but not at exhaust design, resulting in a product that's disappointing across the board. I really hope that's not the case, but right now, data are scarce.

That engine and harness are both well regarded, so I'd say (not an expert here) you can't go wrong with those. I can't say anything about the frame, because I know nothing about details such as the thrust line etc. The one thing that bothers me (a little and without evidence) is the gap behind the pilot's head, but you could close that up yourself with a bit of line if you wished, so not a big deal. Otherwise sounds good to me (repeat: non-expert).

Well that's not what I wanted to hear, but all data is valuable. How does he characterize the power differences (I'm assuming it's feel, not instrumented testing); slight difference? Big difference? Something inbetween?

I look forward to hearing your impressions!

So, Skymax says their v2 titanium exhaust looks the same as v1, and performs about the same. They say it incorporates (undisclosed) incremental minor improvements. If the v1 had specific problems, they're not fessing up to what they were. So, bump. Does anyone have 1st or 2nd hand experience with these exhausts? Thanks!

ok, Both connect and connectiq are on the phone, but I've not been up since the phone arrived. Where should I expect tracks to appear? Can someone tell me what utilities display tracks the way I've seen done on 'tube videos (most likely pc applicatiojns)?

I just bought my new vivoactive4 because of stufly, and aside from some odd behaviors from connectIQ, it's been pretty easy to configure. I do not understand apps vs widgets vs fields and all that blah blah, but that can wait. My main problem is I have yet to figure out how one pulls flight tracks from it and displays them, as I've seen done on 'tube. Have I missed something super obvious, like I slide right over it on some webpage or something?

Oh, I understand. Recall I'm willing to trade off efficiency if necessary; I don't mind "wasting" some of the engine's power into turbulence instead of thrust if that's what it takes to achieve lower thrust without burning up the engine.

If the motors had speed governors, this would all be moot. But we're dealing with primitive, simple engine designs, despite what their cost might suggest.

Yes, might have to tinker with the pitch. Which is why it's not a total no-brainer.

That's altering the reduction ratio as mentioned in the original post. It might be cheaper, wouldn't be easier than swapping props, as propswap is done in the field routinely. Having 2 or 3 props from which I can choose on a given day seems to me an ideal solution, *if* I can determine appropriate design parameters.

In this case, I'm attracted by the low total package weight of the tornado, but under the wrong circumstances (foot launch, minimal gear, low pilot hours) the excess power isn't a benefit but a hazard. Under other circumstance (higher cumulative pilot hours, laden trike), it's a benefit. If 2 strokes had a linear power curve like 4 cycles, a simple throttle stop would do the business. With more sophisticated (read: electronic) engine controls, a power profile could just be dialed in. The traditional approach to covering a wide range of use cases is to just buy multiple motors. I'd rather not buy multiple motors. If buying a few props would do the job, that's far preferable. The published 125cm/80kg data point suggests this should be feasible. And I'm not concerned with fuel efficiency, so that can be traded off for the desired versatility. Make more sense now?

Not gettin' on your case, and accusing you only of being a human, just observing an inevitability. But I am hoping someone knows something germane. Sorry if I sounded snippy.

Indeed, the nature of the beast ( forums read by humans) is if you ask a "how" question, inevitably someone will ask "why would you want to do that anyway?". But it is a "how" question. Super short answer: easily reconfigurable versatility. .

Sure, that's even more prop than the 125 cited on the motors page.

So... We all know the tornado with its signature 140 cm 3-blade props delivers way more power than most people need most of the time, that's a given. And it's also lighter than the lightest moster build. But looking at the engine files page (I don't know if this data comes from AC or not), moster is listed at 75kg static thrust with a regular 125 cm 2 blade, and tornado is listed at 80 kg static thrust when a 125 cm 2 blade is mounted. Not much more; only 5 kg difference. Reference: https://www.custom-air.co.uk/Custom_Air_Paramotors/paramotor_engine_files.html So let's consider the feasibility of nerfing a tornado down to (or maybe even slightly below) moster thrust levels while keeping it easily returned to high thrust configuration if desired. Swapping prop is *way* simpler than altering the reduction ratio. e-props site, with tornado entered in the search box, lists a 120 cm 2-blade offering, but no performance data. Another option is to ask a wooden prop shop to run off something slightly custom. So the question: Has anyone any actual experience, or professional opinion, how suitable that 120 might be for this project, or likewise the wooden option? Any actual, hard knowledge why this might be a bad idea? Thanks in advance!

Yeah, I'm no expert, but if it's been 1.5 years since training and you haven't racked up a bunch of hours, I'd think a day or 2 of refresher might be in order. I'd say continue to beat up the old gear until you're not crashing anymore; then consider new spiffy gear.

Conventional wisdom says a dark plug like that means it's running rich. Also, are you using the run gas/oil mix or the breakin gas/oil mix? And are you sure?

I've been told that's what EOS does: subbed out the exhaust to some Japanese company that makes exhausts for 2 cycle dirt bikes and stuff. Seems the appropriate approach to a specialty part like that. If skymax has a new version in the pipe, that's interesting. I wonder if there was a problem with the one I've seen pics of, or if they improved performance or mfg cost, or what. Well we'll see what they say when they announce it. Maybe. Since you didn't say anything about estimated release date, I'll assume they're mum on that for the moment. (Re the confusion, you posted what looks like a vitto trade show pic, so I thought you were speaking of a new version from vitto. Ah!)

I'm still confused. You asked Skymax about vittorazzi making a new versions of the Vitto Ti exhaust, and Skymax said Vitto has a new version under test?

Um, wait a sec. You spoke to... Skymax or Vittorazzi?

Well they have had one in the past, botched it (apparently their idea of life cycle testing is less than 30 hours, as so many failed at that age), might possibly be making another run at it. Even if they are, and it happens within a year, I predict they'l charge a lot for it. The skymax is a current product and not too pricey. But more than I'm willing to gamble w/o user experience.