Mazda Rotary Club

Cars by Model Type => 2nd generation RX-7's => Topic started by: jimmydanny on October 10, 2010, 06:51:43 PM

Title: Changing the air-meter thingy (english terms)
Post by: jimmydanny on October 10, 2010, 06:51:43 PM
Okay, my car English sucks. The device that measures how much air is coming into the engine by feeling how far a bowlformed thing is pushed in, what ever it is called.

Are there any possibilites to change this to something more.. Aerodynamical? Is there any point in this?

In newer car there are electrical sensors going from 1-5V or whatever, but this one I haven\'t seen before. But it surely slows the airflow to the engine?
Title: Changing the air-meter thingy (english terms)
Post by: TiddlesRX7 on October 10, 2010, 08:12:54 PM
Not sure about changing it for one that flows better, but if you run a stand alone ECU you can remove the AFM (air flow meter) altogether.
Title: Changing the air-meter thingy (english terms)
Post by: jimmydanny on October 10, 2010, 08:16:05 PM
AFM it was, thanks. Yeah, but what does a SAFC cost? And how is it with mapping without dyno? I am not familiar with these things.

Also, we don\'t have anyone who can map a rotary up here I think. Driving 800km for a dyno is a bit too much for me.
Title: Changing the air-meter thingy (english terms)
Post by: jimmydanny on October 10, 2010, 08:17:26 PM
Of course, this will be when I get money to get a beefier turbo, some new injectors, FMIC and fuel pump. Before that it is just a waste of money with an SAFC.

I don\'t start with beefin the HP up before I change the seals in the engine so I know I won\'t blast it.
Title: Changing the air-meter thingy (english terms)
Post by: Kenji on October 10, 2010, 10:45:03 PM
Don\'t use a SAFC.
Get a programmable ECU such as APEXi PowerFC or HKS FCon Pro
Title: Changing the air-meter thingy (english terms)
Post by: jimmydanny on October 10, 2010, 11:37:00 PM
Well that is impossible for me as long as I live here. I got no one to map it, nowhere to map it, and not the money to buy it or map it :P

But when time comes, I will of course do something about the engine :)
Title: Changing the air-meter thingy (english terms)
Post by: jimmydanny on October 10, 2010, 11:37:48 PM
But my main question still remains, there must be a compatible  AFM somewhere in the world that got the same signalrange as the original, but doesn\'t block half the air coming through
Title: Changing the air-meter thingy (english terms)
Post by: Prof on October 11, 2010, 07:21:53 AM
[INDENT]The AFM actually flows air good enough for about 400BHP (although it\'s output is 0 by about 310BHP), and is remakarbly aerodynamic - looks like a jet engine inside, unless you\'re talking about the older flapper ones?
 
Probably the only thing to be gained by replacing it is better throttle response, but you\'d need to go with a hotwire or something similar for that, and the output is completely the opposite of the cone AFM. This is one of the largest of these cone Air Flow Meter\'s - so not much out there to replace it with.
 
If you ever do replace it - there is a thermistor for air temp measurement in the unit - together with the AFM this tells the ECU the mass of air coming in and hence how much fuel to use.
 
I run an emanage Ultimate, which allows you to remove the AFM and use a table of values instead, but even after a lot of tuning, the low rev driveability was nowhere near as good as running the AFM - it does make for a much smoother drive.
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