You aren't considering density.  Dennis is correct in that you still need
TPS and IAT to do the proper calc if you wanted to retrofit and feed a
signal into the bosch ECU that it could use.

We have data from a bunch of AFMs as to what they flow and what voltage they
read at a given flow. They aren't linear, I wish I could provide this
data... BUT let me just say this... even if you have that data, it won't do
anything for you. I know this is a little cryptic, but it'll make sense if
we can ever *@#(*^$!@ release our LMU and some of our development info.

I'm pestering Matt (who is our electronics guy) to deliver on the next rev
of our boards, but he's been swamped on a project that actually delivers
money at his other job, so we lose in terms of priority.  If we scrap the
project, I'll make everything we learned public domain (which may also
happen if Bostig goes non-profit anyhow)

Thanks,

Jim
________________________________________
Bostig Engineering
Engine Systems Voodoo
http://www.bostig.com/
617.272.3800

-----Original Message-----
From: Greg Potts [mailto:greg@POTTSFAMILY.CA]
Sent: Saturday, November 04, 2006 2:24 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: AFM Voltage Ratios

Hi Mike,

CFM to RPM is easy... a 2.1L engine pulls 2.1L of air per RPM.

One liter = 0.0353146667 cubic feet. So a 2.1L engine at 1000 RPM
pulls 74.1608 CFM

Happy Trails,

Greg Potts
1973/74/75/77/79 Westfakia "Bob the Tomato"
www.pottsfamily.ca/westfakia
www.busesofthecorn.com

On 4-Nov-06, at 2:06 PM, Mike Bucchino wrote:

>  You could bolt an AFM to a flowbench and run tests to determine these
> voltage changes for a given CFM, but you'd need to know how CFM
> equates to
> the engine's rpm,