I thank you a thousand times over for that web address! I'd not come across it
before, and it
gives some of the clearest examples of scope profiles and diagnostics that I've
ever seen for EFI
O2 sensor readings.
If I managed to sound like I think one can perfectly tune their car using an O2
sensor gauge, I
apologize. I do find them useful, just as I find a vacuum gauge quite useful.
But they are
certainly not the end all be all of car tuning.
I have not actually installed mine yet, for a thousand one one reasons (ok,
they're excuses).
But I have seen them in use on cars, and each of those were EFI vehicles. The
gauges definitely
would go out of the normal ranges. There are some reasons for that.
First, these were not stock cars. Headers, cams, repromed, etc. As well as
tweaking the signals
to the computer with varistors in line with the temperature sensors and such.
Second, many EFI engines run out past their fuel injectors when being flogged.
Hondas being one
well noted for this. Especially if you modify the engine even a little bit.
On these vehicles,
you go lean when racing because you can't do anything but in stock trim.
Along those lines, have you seen these little computers you can put on your EFI
car to really
play with the computer and engine tuning? Team23 showed me one at Carlisle
this spring that was
truly amazing. http://www.customizeyourhonda.com You placed it in line with
the sensors, and
have a dashboard mounted display and control panel. You can program into its
memory I think six
different engine running profiles. Cost about $350, but seemed very
worthwhile. The running
differences were astonishing. I think it was the one called Venom if you're
curious.
Coming back to Spitfires, with their delightful needles and the hundreds of
profiles available, I
strongly suspect that an O2 sensor and gauge would be one of the best tools for
helping to select
the proper profile needle(s) for a given engine, in a given trim and condition,
being driven in a
given way. It would help pin down the causes of the various flat spots in
performance that are
otherwise impossible to well define. No, it's certainly not going to tell you
how many mm's you
need to change a needle at any station, but it gets you into the area with a
direction by letting
you know that you're going rich or lean under conditions other then idling in
the driveway.
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