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-   -   Stock 1.6 AFM limit (https://www.miataturbo.net/diy-turbo-discussion-14/stock-1-6-afm-limit-34729/)

ARTech 05-04-2009 01:52 PM

Stock 1.6 AFM limit
 
I must be doing something wrong, because I can't find it in a search. I'm sure it's come up before.

At approximately what hp does the stock AFM max out? How much airflow can it read before it's pegged at 0v?

Or is it not as simple as that?

Braineack 05-04-2009 02:28 PM

Car goes into open loop at 4500RPM....so the readings matter little.

ARTech 05-04-2009 02:37 PM

Open loop still should take into account at least 2 paramenters though, load and rpm.

Joe Perez 05-04-2009 02:52 PM

It's already damn near pegged in stock form.

From the link in my sig, here's a complete map of the 1.6 AFM's output. RPM is on the bottom, voltage is on the left, and each colored trace corresponds to a manifold pressure. These were taken on my EMU, so they're in relative PSI, where 0 PSI is atmospheric (100kPa).

http://miatajoe.50megs.com/afm_plot.gif

Note that at redline, there's virtually no difference between -3.6 and +0.6. Also, this data is slightly "more optimum" than real-world, as I cleaned it up, did some extrapolation based on what I felt the curve was intended to look like, and intentionally made sure that there was at least some differentiation between datapoints, at least on the non-boosted side.

FWIW, this was with a Greddy turbo and a DIY "wide-n-narrow" FMIC.

ARTech 05-04-2009 09:37 PM

That's some great work Dr Perez. Thanks for taking the time to plot all that out. I'll eventually get rid of the AFM altogether, but for now, the EMB is what I'm working with.

You're right, resolution is crap. I guess I'll buy the MAP sensor.

Stephanie Turner 05-05-2009 06:13 PM

The most you will get is about 200-210 whp.
Stephanie

ARTech 05-06-2009 01:23 AM

Thanks. I'm just going to play it safe and tune based on MAP.


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