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Aftermarket Injection & Cali Emmision



Well, there's no doubt that Megasquirt can pass an emissions test.
I just recently passed an idle test with flying colors, 0%CO and 16ppm
HC out of a maximum of 250ppm. And that was done with literally some
last second adjustments to the tuning since I failed to understand and
compensate for an overheated intake air sensor that was leaning out
the mixture quite a bit.
Plus I've passed roller tests, again with very good numbers, with a
Haltech which is a nighmare to tune compared to Megasquirt.
All the Megasquirt variations will run closed loop mixture control.
Some of the Megasquirt varitions will also autotune which basically
means that if you can get the engine running the MS will autotune the
fuel map for you although MS will only tune to the AFR target table
that you provide.
Note that with a Narrow band O2 sensor MS will only tune to
stochiometric, which of course is exactly what you want for minumum
emissions.
With a wide band O2 the engine can run closed loop to any AFR you specify.
Setting up the various starting and warmup enrichments plus the accel
enrichment are things you need to manually tune. If you understand
when each enrichment functions it's not that hard to isolate which one
to change to properly tune the car.

There is also some really cool tuning software, Megalogviewer, that
will analyze datalogs and suggest changes to the fuel table.

Ignition is another thing. There are no tuning tools, other than
retarding the ignition if the engine pings or using a knock sensor
which some MS variations support. Keep in mind that setting the
ignition just short of ping is not necessarily best for either
performance or emissions though.
This isn't a ball buster though since there are several people that
can supply a good ignition map for your engine.
Obviously installing and tuning something like MS is not child's play.
But if you have a decent understanding of how your engine works, what
AFR's the engine needs to run at and what the ignition advance should
be for various load/RPM points then it's not rocket science either.
So, bottom line is that MS can be tuned and set up to pass an emissions test.
What problems there might be if somebody opens the hood and sees
non-stock engine components, I cannot say.
HTH.
Dan


On 2/16/07, T Berk <bayareaberk@yahoo.com> wrote:
>
> Maybe this is in the archives (and esss-cuse me for
> not doing do diligence 1st) but I was wondering if
> somebody could condense what the ups and downs are for
> doing something like a Megasquirt conversion on a
> street car ('81) in California's anti-smog
> environment.
>
> In my case It's a 1.8, 10:1 transplant into what
> originally was a 1.7, 8:1 base chassis.
>
>  I really like the whole 'tune it yourself' aspect but
> I need to minimize the federales involvement under my
> hood if possible.
>
>
> tia,
> TBerk
>
>
>
>
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