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i was thinking about why the s-afc won't work well on out cars(cause when in wot it has a preset fuel map) and i was wondering if anyone has tried running a safc but not letting the stock ecu know that your are at wot, only letting the safc know, so then u can still have 2 different fuel maps one for crusing and one for wot

would this work

anyone

That is the reason it doesn't work effectively with "our" cars. The TPS is an on/off version, it does not provide a signal for anywhere in the middle of the on/off signal. So in effect, the low throttle setting is anything that is not at WOT, high throttle setting is only at WOT. A remedy to this, and a mod that many have started to do is to remove the TPS as the actuator and replace it with a MAP sensor. A MAP sensor will give you the low throttle setting for essentially all stages under vaccum and high throttle setting for everything under boost.

Here is a tech article for the mod: Fooling the S-AFC

I hope this is what you were getting at, if not, clarify and I will try to help further.

When I go to the monitor part of my AFC I see more than either a 0 or a 100 percent. It is not just an on or off thing. Maybe the DOHC guys dont have this problem? I sure dont.

<small>[ January 18, 2004, 12:05 PM: Message edited by: cjthor ]</small>

When you go and monitor the input voltages, what voltages are displayed for the TPS? You should see approximately 0V and 5V. Possibly the DOHC versions had a TPS with variable voltage, in that case the S-AFC would work as it is supposed to. Not sure why yours would have a variable TPS when not even the Miata came with one.

Almost positive its variable. I will check today.

the S-AFC only has 2 fuel maps right
so then why do you need variable tps?

The simple on/off TPS that the MX-3 has will provide the low throttle fuel map for all conditions other than WOT which is when the high throttle map takes over. Essentially then, 99% is covered by the low MAP and 1% is covered by the high MAP. The benefit of the variable voltage TPS allows blending, meaning that when you set your S-AFC to have the low map for all voltages 80% or less of the max voltage it will do so, likewise 20% of max voltage or greater will be the high map. It will allow better tuning under acceleration.

u know.....
i saw an article where they converted a miata maf to map, but superstreet doesnt have on there site anymore, i was thinking i could be done on the mx-3...i might try when my mx isnt a daily driver anymore

Ok for all you guys with an afc. When you are on monitor mode what does your throttle percent show...does it progressively go up or is it just 0 and 100 percent.

0 or 100%, never in between.

FYI, the Superstreet conversion from MAF to MAP was with the installation of a FM link.

FYI guys the DOHC TPS is variable. 0-4.5 volts.

Lucky for you.

yeah i know that the link was for a fm link.....
but would the conversion be possible in the mx

In my Gs the TPS voltage raises progresive and accurate, and the S7afc works on Wot or partial. It has been shown on my A/f ratio gauge!