[Diy_efi] O2 sensor sensitivy speed

[Shannen Durphey]

Bruce wrote:

> 
> Isn't best to design things so that all cylinders contribute equally?.

This hints at an old notion that has been batted around some but is rarely
mentioned, that building of an engine should involve a balancing process of sorts
with each cylinder.  For anyone who doesn't have money to invest in a top o the line
block, heads, parts, and a ton of machine work, the thought is to adjust the
compression ratio for each cylinder to prevent the "runt" cylinder from weakening
the others.

> Individual cylinder trimmings are just covering up for other malfunctions.
> I don't see where one is easier then the other, 
Only that the hardware is designed to do it, so that's what seems easiest.  With the
resolution of the P4, it would seem that tracking cylinder position is not too
difficult for timing issues.  I can only imagine what could be done with the 8051
and the cam/crank position strategy on the LT1.

> the trick is figuring out
> which cylinder to work with.  And now that I think about it some, I think
> timing would be the better answer.  

Yep.  Fuel only would allow timing for strong cylinders to stay at maximum.  But the
cost would be additional fuel usage over what's needed, and likely less than max
potential power in the weak cylinder.  

> It's easy to swap injectors around,
> given a set that have been flowed,  then use the timing as a stop gap.   I
> think using fuel control is alot of work to cover other problems, when a
> simple injector swap would answer the fuel delivery.
The next step after answering fuel delivery for most conditions is to be able to
trim it for all conditions.  

Of course, the "perfect" way to go is consider an engine to be multiple single
cylinder engines.  Then everything would be handled individually, and we would have
less incentive to chase the "perfectly balanced" set of mechanical components, and
so theres much less need to build the multiple compression ratio engine.


>   After studying the plugs out of the GN with the big plenum manifold I
> think more then ever the mechanicals need optimised alot more then people
> think.  
Imagine trying to do some of this optimizing with a carby and points!  I think
people just don't realize what the electronics will allow them to do with the
mechanicals.  Old tricks seem slow to fall away.  Anyone on the list running a 160
thermostat please raise your hand.  Now go write a 6k email based on research in the
archives why this is not a good idea. <g> 

> Batch or SEFI is fine for getting the fuel evenly distributed, it
> the air that's being overlooked, again all my opinion (some supported by own
> little experiments <g>).
Air?  We don't need no steenkin air!

(Still looking for illustrations and notes regarding Tesla's oxygen compressor [or
was it a distiller?] for internal combustion engines)
Shannen

> Bruce

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