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Thanks, Mark,
Interesting, I was wondering about that. I was told
(way back when) that the lead in gasoline would also kill the narrow band
sensor after a few seconds. It does apparently render it useless for it
emission control purposes in an auto due to in increase in the hysteresis of its
response curve. However, for just providing a voltage indicative
of O2 content of the exhaust - it still works fine.
I have flown with 100LL 99% of the time since 1997
and have only needed to replace the narrow band O2 once. So that puts
another nail in the EFISM WBO2 project.
Ed
Sent: Monday, August 29, 2011 4:29 PM
Subject: [FlyRotary] Re: How to tune with ADI?
David,
My wideband O2 sensor started acting up soon after I switched to 100LL.
I called the company rep to talk about a warranty replacement and he said
that leaded gas will kill the sensor (and offered to sell me another sensor).
I mentioned that there was nothing on their web site that said not to use
with leaded fuel and he (basically) said, "so what". So, save your money
if you're running 100LL.
Mark S.
On Mon, Aug 29, 2011 at 3:19 PM, David Leonard <wdleonard@gmail.com> wrote:
Thanks Bobby,
What number are you looking for for
mixture?
On Mon, Aug 29, 2011 at 7:24 AM, Bobby J. Hughes <bhughes@qnsi.net> wrote:
David,
Where are you
injecting the water?
I am injecting into the plenum just before the throttle body and
after the intercooler.
Here are the few
facts I think I know about
water injections.
- Water is
better for detonation prevention than an alcohol
mix.
- Alcohol
mixture allows timing advance and more
HP.
Those are contradictory points. For, what is it that allows more
timing advance other than prevention of detonation. I think you mean
that water is better at cooling, but alcohols make up for it by providing an
apparent increase in fuel octane as well as cooling.
- Injection in
the intake some distance before the engine block = more
cooling.
- Injection at
the block = better detonation
margin.
what is the purpose of cooling other than improving detonation
Margin?
- Windshield
wiper fluid is a good alternative to dealing with methanol. Usually about
40% alcohol.
Not in Southern California. They
sell blue stuff but I cant find any rated below 20deg F (7%methanol). I
even found one, a deep blue color, going for $4/gal no less, that proudly
proclaimed in big letters: "Protects from freezing down to 32 degrees!"
Also a good wideband
is very useful. http://www.jdmpartswholesale.com/product/plx-dm-5-wideband-o2-52mm-display-sm-afr-combo-black
It’s my most used instrument.
I
Guess I should break down and get a WBO2 like the one you linked. But
that is an expensive sensor that I will probably burn out with 100LL.
Have you had any problems with 100LL?
--
David Leonard
Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net
From: Rotary
motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of David Leonard
Sent: Sunday, August 28, 2011 10:24
PM
To: Rotary motors in
aircraft
Subject: [FlyRotary] How to tune with
ADI?
Ok, So I have the new ADI system installed and
working.... I think?
Some of you smart racing guys probably have experience
with ADI.
Most of the instructions that come with tuning it are
directed toward car guys that have computers and knock sensors. All they
do is turn the system on and the computer allows more advance because I is not
sensing any knock. The only real advise I have so for for me is that I
should be running just less than the amount of ADI that it takes to bog down
the engine. My system is a fixed flow so I don't have much choice but it
seems to be about right. If I use straight water (which I did for
initial testing), the engine bogs after about 10-15 seconds of ruining the ADI
system. But when I uses a 50/50 mix of water and denatured alcohol (too
hard to find methanol around here, but close enough) the engine does not
bog.
So assuming my amount of ADI injected is about right,
now I am supposed to be able to lean to better power and advance the timing a
little. But how much? For the last testing flight I was using EGT
for lack of a better guide. When the ADI comes on, my EGT drops by about
30 deg C, and there is a hint of roughness to the engine. I can then
lean a little and the roughness clears up. For my test flight I leaned
until my EFT came back up to where I normally limit it (890 deg C). But
if I then add 5 more inches of MAP, there is still a hint of roughness even at
890 deg and I get the sense that it wants to be leaned a little more. But I am
afraid to do that... We are talking 45" MAP and 7300 RPM here (185 KTS
indicated (Vne) and climbing at 500 fpm).
So here are my questions:
Is EGT a useful tool here, and does leaning to get the
EGT back to 890 make any sense?
Since Methanol will do such a good job at preventing
detonation, is it safe to lean further toward best power (peak EGT)? (note,
that will be hard on the turbo... I need to remember to bring the
spare one to Reno)
How much advance do you think i can add?
I was previously ruining 5 deg ahead of Tracy's recommended initial
set up. Can't give a number because the EC2 retards the timing with
higher MAP's. How much, I have not heard. I can easily add one deg
at a time using Ed's EFI monitor. But without a knock sensor am really
in the blind.
--
David Leonard
Turbo Rotary RV-6
N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net
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