[Diy_efi] Adapting Ion Sensing systems

[Bevan Weiss]

I assume that you guys have read:

http://www.fs.isy.liu.se/~larer/Projects/main.html

A paper for the IEEE from the same guy:
http://www.fs.isy.liu.se/~larer/ISIS/Doc/NieEri_1998_CSM.pdf

http://www.squirrelpf.com/msavr/index.php?page=IonSense

http://www.x-dsl.hu/genboard/knockdetect/DIY-Ion-Sensing-2.pdf


> -----Original Message-----
> From: diy_efi-bounces at diy-efi.org 
> [mailto:diy_efi-bounces at diy-efi.org] On Behalf Of Adam Wade
> Sent: Friday, 7 May 2004 1:46 p.m.
> To: A list for Do-It-Yourself EFI
> Subject: RE: [Diy_efi] Adapting Ion Sensing systems
> 
> --- "Daniel R. Nicoson" <A6intruder at adelphia.net>
> wrote:
> 
> > My point in pursuing ion sensing is the real-time control they can 
> > provide (or so all the technical papers say).
> 
> The problem is that ion sensing is not a single thing; it is 
> a technology that can be realized in many ways, from 
> primitive to extremely complex.  In theory, you could do 
> real-time closed-loop spark timing with a sufficiently 
> sophisticated ion sensing system...  But the cost would be 
> extremely high, and it would still require some 
> trial-and-error to get some baselines to work with.
> 
> > As a shade tree tuner without a nice dyno cell, optimizing a spark 
> > table with aftermarket cylinder heads, cam etc. is purely trial and 
> > error regardless if one just wants max power OR emissions.
> 
> That is true of most tuning to some degree, although there 
> are tools that will allow you to cut that significantly.  A 
> four-gas analyzer and an eddy current dyno running "step" 
> tests can tell you a fair amount about your spark timing, and 
> what you can do to improve one area or another, without it 
> having to be all trial-and-error.  Such a setup will speed 
> tuning of both fueling and spark.
> 
> > Worse than trial and error, I have yet to see much of a way to 
> > optimize spark advance except to advance until knock and 
> then back off 
> > some.
> 
> That doesn't "optimize" spark, necessarily.  More advance is 
> not automatically better (detonation issues aside).  Possibly 
> more important are things like spark location and combustion 
> chamber shape, as well as things like mixture quality and 
> mixture content.  This is one area where closed-loop spark 
> control would be of great benefit, but as I mentioned, the 
> complexity and cost are exceedingly high at this point, as I 
> understand it.
> 
> > Of course on a boosted application this isn't a very good procedure.
> 
> And very, very far from optimal (of course this is true, 
> since holes in pistons are bad for power and emissions both).
> 
> > Anyway, I was hoping someone had stumbled on a project that 
> was in the 
> > DIY-useful stage.
> 
> Someone was working on a project with a MEGA controller here 
> a bit ago that was purported to have some level of ion 
> sensing, although I am unclear on just how complex it really was.
> 
> TTBOMK, there are no manufacturers in the auto or motorcycle 
> world who have the complex kinds of ion sensing systems on 
> production vehicles at this point in time.
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