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TahoeThor

Vortex 243

10 posts in this topic

I have over 20 hours on my 2017 Vortex and the max RPMs have never increased since day 1.  I am getting 5600-5800 out of twin 200s with a max speed of 30-31 mph.  Called my dealer today and he claimed that was typical for the elevation at Tahoe (6,200 feet).  My research shows differently.  

 

any advice?

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If the dealer says that's the way it is and you disagree, probably not much choice other than to take it down in elevation and see what it does.    Probably not a lot of data on them at that high of an elevation.  A local lake is around 2500 ft elevation.   The dealers mostly stick boats with the big engine options.  A friend just bought a new 24' boat with the 350hp Mercury.   He only gets 41 mph. 

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A normally aspirated engines looses about 3% of its power for every 1000 feet of elevation. So you would be down 18+ %.  

If the engine is supercharged or turbo charged the loss is minimized. 

brick

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I just read somewhere that someone was at Tahoe with a vortex and was getting up to 41 or so top speed.  Not sure if it was 200's or 250's.  If you are up there at all times, I would talk to a rotax person and see if it can be re-tuned for the high elevation.

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Firstly, thanks to all three for the feedback.

i would expect some degradation in horse power from the altitude but what I think has happened is the electronically governed break-in period has for some reason never kicked off.  Pretty sure the super chargers have never activated.  There has been zero increase in power from hour 1 to hour 20,  was told to expect a boost in power after 8 hours.   I read of someone else having the same issue and it turned out to be a software problem.  The Medallion Viper II seems to have a ghost in the machine.  Will have the dealer scan it next week and hopefully find an answer.  I sure wish Chap had a customer service line for these types of questions.  Do they even check these forums?

Thanks again,

T

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The supercharger is always "on".  Sounds like a glitch. The dealer should be able to figure it out. 

brick

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7 minutes ago, cyclops2 said:

Some dealers sell boats.............. Period.

Agreed. Hopefully his dealer will assist and figure out what is wrong. 

brick

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I used to have the 223VR with twin 200's and at sea level max rpm was 7,800 (55 mph), but during the 8 hour run in period the max rpm was around the 5,800rpm range with a similar speed to what you are getting, but once past 8 hours all the restrictions were off, i'm very surprised you didnt get any noticeable change.

A rough rule of thumb I was given for an engine at altitude is it loses around 3% of its power per 1,000 rpm so you would likely be around 20% down, but I would expect the superchargers would help at altitude ? , hopefully there are some pilots on here that may have experience of that.

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A jet pump drive usually does not have a big selection of pump blades for higher altitudes. I did a quick check of losses. Might not be correct way. 20 % of 7800 rpms is 1,560 rpm loss.  So 7800 rpms - 1560 is 6,240 rpms.  That seems far enough away from the result you get. Call Vortex directly. Only sure information. Might have a pump exchange for your height. Maybe a freebe if the dealer DID NOT specify the optional pump.

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