Combustion Pressure Sensor - revisited

[Greg Hermann]

>The current interest in continuous combustion pressure sensing is driven IMHO
>by two conflicting needs - to improve milage for CAFE and to reduce emissions
>further.
>
>By watching pressure in the lean region, it can also be used to run close to
>lean limits.  This is done by monitoring pressure turndown and if the peak
>begins to decrease, slightly richen the mixture.
>
>Directly measuring the combustion pressure reduces the utility and criticality
>of other measure measurements as it directly reads the desired result instead
>of divining the entrails.
>
>Certain year imports are rumored to have direct cylinder pressure sensors.

All EXACTLY spot on, Bob! One of the few times that I have seen anyone
write down that a good, quick burning chamber design avoids the need to
advance to incipient knock, but very true! You been talking to Keith
Duckworth lately??? :-) (Or just reading Glassman?) Only thing that I would
add is that I THINK that there is no such thing as TOO quick a burn--so
long as the patterns of turbulence in the chamber are CONSISTENT. I think
that the urban legend that too quick a burn leads to a rough running engine
should read more along the lines that an inconsistently quick burn (as
would be produced by randomly inconsistent patterns of turbulence in the
chamber) is directly analogous to varying the timing randomly, and
therefore the engine runs rough!

But--I gotta be the owl now--WHO?? WHO??

I have heard rumors of fiber optic based im chamber pressure transducers
that have the potential to be production type reasonable in cost, and also
warranty type robust--but haven't ever seen anything.!! Does anybody know
of any of this kind of stuff that is out there, particularly if it is in
production?? If in production, what is the application??

>Wouldn't it be sweet to instead of compensating for to optimize changes on the
>fly.  Conceive of each cylinder having optimum timing independent of all
>others, each cylinders power exactly matching the others etc.  It will happen
>as the combustion pressure sensor ( Trionic or otherwise ) moves mainstream.

Enough to make a guy drool!!

BTW--whaz been happening with your plasma - jet ignition experiments?? We
want DETAILS, and part #'s!!

Regards, Greg