Ed,
Yes, Auto Tune does work on the ground for most, but not all, map table addresses. There are certain map table addresses that you just can't get to unless you're actually flying the airplane. Those are the ones that the EC-2 needs for flying in the pattern and approach modes. You need to go to a safe altitude and simulate a landing, while in auto tune.
Mark
On Thu, Jun 25, 2009 at 7:53 AM, Ed Anderson <eanderson@carolina.rr.com> wrote:
You are correct, Mark. If did preface my observation with “IF your fuel flow is calibrated and accurate..” {:>). Which could be a big assumption.
However, not being familiar with the Auto Tune feature, I have no idea what is required to calibrate the fuel flow or whether you can do it on the ground or not. However, Chris did indicate he was attempting to use the “Auto Tune” feature – which I believe is for tuning for cruise not best power. IF that assumption is correct then it begs the question of whether it affects full power WOT operation or is automatically cut out of the fuel control loop under that condition.
I just thought the suggestion to turn it off or temporary disable the Auto tune might be an easy thing to check to see if it affected the RPM and fuel flow.
Ed
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Thursday, June 25, 2009 8:09 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Auto Tune vice Max Power???: [FlyRotary] Re: Consistant progress...not sure how to act?
Isn't that a pretty big assumption to expect the fuel flow to be calibrated and accurate considering that he hasn't yet flown and just switched to larger injectors? I've been flying for two years and I'm not done tweaking the fuel flow calibration on my EM-2. If that is in fact the case, isn't everything else a moot point?
On Thu, Jun 25, 2009 at 6:24 AM, Ed Anderson <eanderson@carolina.rr.com> wrote:
Chris,
IF your fuel flow is calibrated and accurate a fuel flow of 11 gph at 5870
rpm and 29" Hg, that would indicate an air/fuel ratio of around 16:1. Now,
I am not familiar with Tracy's auto tune function (no EM2), so don't know if
it's trying to achieve a 14.7:1 Stoichiometric ratio or not - but, my
calculations indicates your engine may have been running a bit lean for best
power.
For best power you want an air/fuel ratio of around 12.65:1. If you have
that A/F ratio then your 5870 rpm at WOT and 29"Hg would give you around 155
HP with a fuel flow of around 14.4 gph.
I don't know if you can, but IF you can, I would turn off/disable the auto
tune feature and try just manually adjusting your fuel mixture knob to give
you a richer A/F and see what that gives you. I could be wrong, but my
understanding is that the auto tune is more for tuning for economy rather
than max power.
Ed
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
http://www.andersonee.com
http://www.dmack.net/mazda/index.html
http://www.flyrotary.com/
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.rotaryaviation.com/Rotorhead%20Truth.htm
-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Christopher Barber
Sent: Thursday, June 25, 2009 4:43 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Consistant progress...not sure how to act?
I went out tonight and checked for leaks and could not find any, but you
are right, it is likely idling too high. I will likely remove the
suspect part of the manifold and give it a more diligent inspection.
The Mistral intake is two major parts. The part that is bolted onto the
engine has nothing that could leak. It is connected to the throttle
body portion by aluminum tubes. The throttle body portion has a couple
of places that could leak. That being said, I was intense in my method
to seal the the openings that Mistral provided to attached various hoses
that I am not using. However, I will verify.
I did verify that the throttle is closing all the way, so I got some
more investigating to do.
In a similar note and perhaps this should be more directed at Tracy but
how does the EM2 determine Horsepower and Percent of power. Tonight
when I cranked the power to full at about 5870 rpm's I was looking at a
fuel flow of about 11 gph (which if I read previous post correctly is
low) and a HP of about 93 which indicated 50% power. Now, I was at FULL
power, but is was indicating 93 HP and 50% power. Whats up with that?
OH OH OH, the MP was showing 29. (for once I remembered to look <g>)
I did learn something tonight. If I forget to turn on the fan while
sitting on the ramp at 86 degree Houston night, my temps shoot up much
faster.
I do think my staging point is either 15 or 15.5 by looking at the
asterisk coming on and off while near idle. I have had my EC2 since
2005 and even though Tracy has updated it, I think the staging is the same.
I am still working out EC2 issues. While it is running much, much
better, it still seems to change subtle elements of the MAP table on its
own. I don't know yet if this is due to my attempt at using Auto Tune
mode or not. It seems when I shut it down at night and come back the
next days, minor difference are present. Not sure why it seems to have a
mind of its own. Of course, getting time to focus on the differences is
difficult. I know, I am preaching to the choir, as we all have time
constraints.
I hope I am actually making progress <g>
All the best,
Chris
Al Gietzen wrote:
> I meant to note the MP but forgot. IIRC the MP was what I considered a
bit
> high at about 15. Since this is where Tracy has the staging point by
design
> (15 or 15.5 I think) I noticed it
>
> Chris;
>
> I see Map of 10 - 11" at idle. By 15 it's putting out some serious power.
> Either the throttle isn't closing or you have a pretty serious leak.
>
> I think on the more recent versions Tracy has been setting the default
> staging higher, like 16.5 - 17".
>
> Best,
>
> Al
>
>
>
> --
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