Dave,
Thanks again for the input. And you are right, I may be barking up the
wrong tree. But I am not convinced that I am......yet (-:
I had not discounted the fuel as a problem at Bonneville but have no way of
proving it.....without some flame front or similar data to compare with
some other fuel burn rate data. I thought that if I could get the data on
gasoline from a few sources, ERC being one of them, then I could compare
them with each other and also to methanol. Methanol would, in my mind, be
more constant in burn rate than racing gasolines that the manufacturer
fiddles with all the time. ERC gas seems to burn slowly but very hot. This
could explain why the EGT is high there and trying to move the heat back
inside the engine by more spark advance hurts the engines. At least it hurt
our engine last summer. With the addition of the "heat" factor......more to
consider.
Skip (pig headed but still after it after all these years!)
At 10:26 AM 3/2/02 -0500, Dave Dahlgren wrote:
>Skip every text I have ever read defines Ve as the breathing ability of the
>engine. No where in any of the equations is there any reference to flame front
>speed. You can get mean numbers for flame front but that is the best you can
>hope
>for. Those numbers are different on a cycle by cycle basis. Even worse it is
>about impossible to calulate the numbers in both directions in that the
>requirement for one cycle is dependant on the previous one to a certain
degree,
>so without knowing what has happened in the last cycle it is hard to determine
>what needs to be done in the next one. Micro proccessors are helping some
there
>measuring the ionization characteristsics of the spark and getting some useful
>info there. The real problem you are having is the fuel characteristics at
>Bonneville. I have had the same problem with several cars in that all the
>expected things do not seem to work and the EGT is universally too high no
>matter
>what you do. I have struggled to get below 1450 there and am personally
>getting a
>little lost to be honest. I feel it is the fuel and there is nothing that
>can be
>done about it as far as I can see. The only other issue seems that it may
be a
>cooling one at Bonneville in that you are on the throttle for minutes. The
>other
>issue is whatever the ambient temperature goes up so does EGT but this would
>only
>be about a 20 degree difference as most dyno cells are about 85 or so to
begine
>with.
>
>This in general is not information that you are going to get that will be
>useful
>in the long run no matter how useful it may seem. All I would think they can
>provide you with is the speed under a certain set of lab conditions, which
>probably do not have anything to do with your particular engine but hey use
>it if
>you will be I am willing to bet it will be something that will only send you
>off
>in a different direction that might not have anything to do with what needs to
>get done.
>Dave
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