I had an idea the other day. The RX8 computer keeps the engine
         at stoichiometric mixture ratio at all times according to the
    OBD II
         data
         I have captured so far on my RX8. Even under full throttle.
         Stoichiometric
         is 14.7:1 to one as I recall so that is not the best for best
    power.
         Best power happens at 12.5:1. Cheap way around this is to
         fool the stock computer into thinking it is getting more air
    than it
         really is.
         Consequently it will put out more fuel richening the mixture.

         The idea is you program a $50 PICAXE computer to take data in from
         the mass airflow
         sensor and the throttle position sensor and modify the mass air
    flow
         data going
         to the stock computer when the throttle is wide open. This device
         could be installed by disconnecting the mass air flow sensor
    and the
         throttle position sensor and plugging them into the PICAXE. Two
    cables
         coming out of the PICAXE could then be plugged back into the
         sensors. This way
         the standard RX8 engine configuration can be easily and quickly
         restored by doing the
         install in reverse.

         On the other hand when the throttle is partially open during
    highway
         cruise
         you could lean the mixture to get better MPG. The rotary will
    run at
         mixture ratios
         of up to 17:1 or higher at steady speed low load freeway travel. I
         don't know exactly
         what this will do to the catalysts so do this at your own risk.

         --
         Paul Lamar ...No rotor no motor.

    Hi Paul,

         Sorry, but at full throttle/high rpm - or any time you are off
    closed loop - the mixture is not 14.7.  Stock typical ratio at high rpm
    is ~11:1 to 13:1, sometimes less.  Even in closed loop, the target
    mixture is mapped and varies up and down from stoic.  We tried hard and
    could not improve the mix in feedback from stock.  Above that, we did
    make some improvement (~5% max), and that is what we deliver in the
    reflash service we now offer.

    Jim Mederer

    Ops you are right. I forgot I took this acceleration run in 2004. I
    was wrong.
    Here is a screen capture. Yep Lambda goes rich.  I was looking at a
    lot of
    steady speed data.

    BTW note how much higher temperature the intake system is than ambient
    air temp. Looks like it needs some insulation.

    Well then only half of my half ass idea will work. The lean part. I
    have never seen
    Lambda go much over 1.02 on the RX8 which is about 15:1. I have seen it
    go well over 15:1 on the Honda Odyssey. I think you could lean
    it on the freeway to 17:1 or 18:1.

    Most of this data is for a piston engine
    but we have found the rotary will run much leaner. A lot of our guys
    are cruising
    their engines at 17:1 or higher.  My guess is.... it is
    naturally stratified charge due to the rotating combustion chamber.

    Of course it will never be as good as a turbo compound rotary.

    The advantage of the PICAXE over the reflash is it can be
    reinstalled cheaply and quickly.

    Paul Lamar ...No rotor no motor.


Stoich has to be nearly the highest EGT, and hence the hardest on the
cat(?)..  I guess richer allows the cat to clean up the HC and yet still
stay cool, while lean may cause excess NOx which the cat can't do
anything about..

Then again, reading up on NOx production, it appears that Honda has a
method for dealing with Lean Burn emissions - as maybe you have seen Paul:

http://www.insightcentral.net/encyclopedia/encatalytic.html


Another interesting article (though somewhat biased):

http://en.wikipedia.org/wiki/Lean_burn
<http://en.wikipedia.org/wiki/Lean_burn>


Matt-

Yes I noticed that Honda stuff on nox. That should help
the rotary if implemented.

-- 
Paul Lamar ...No rotor no motor.

What did we arrive at that was the best oil for our RX-8 engines? Milo

Idemitsu for the oil pan and 2 cycle oil for the apex seals.
Mobile One is good for the oil pan is good.