Hi Club4ag, I have an AE86 with a 4age 16v Bluetop (Stock Ecu/TVIS)

I was wondering if anyone has any Experience with Modifying/Adjusting the Air Flow Meter??? Or adding an Adjustable Potentiometer in line with the ECU for the Water Temperature Sensor???

http://www.ae86boy.com/power.html

http://www.mr2ownersclub.com/mr2sc/webs ... 20Fuel.htm

I understand this is definatly not the "Best/Safest" way to modify the Fuel/Air Mixture, and that an aftermarket Programable Ecu is the way to go...
But this is Inexpensive and I am willing to try if it gives any gains in Acceleration or Power. ( Everything can always be reset to factory settings)

My Hachi has Aftermarket OBX Exhaust, Cams, 3" Cold Air Intake, NGK Ignition, Port/Polish Headwork, Etc... So i feel like it could really benifit from a bit of Extra Fuel (Note: This is strictly a Track Car, Not a "Daily Driver")

Has anyone tried Either or Both of these modifications with success??? Any feedback is greatly appreciated!

I can tell by your post that you do not yet have a wideband gauge.
Yes you can use the AFM and other tweaks to tune the stock fuel system.
You should not do it without a wideband and have just as good a chance of making things worse without one.
For example one of my customers who stepped up to 11:1 compression and poncams found out his motor was still running too rich. He managed to pick up some power by leaning it out.
One thing to remember is that the AFM measures and compensates increases in VE so unless you are exceeding the design limits of the stock system it will compensate for added airflow. Considering the 4AGE runs too rich anyways these combined give you a lot of room before you start running too lean.
Get a wideband and tell me what your AFRs are and I might be able to make some suggestions.
I only have a couple on my website but I can get most brands.
http://www.matrixgarage.com/?q=store/wideband-gauges

What size cams are you running?
What compression?

That first link reads like a high school research paper. A well researched paper granted as there is some good and accurate info in there but there is also a lot of BS. I couldn't be bothered to scan through more than about half of it.

I would never do a pot mod. The miracle of fuel injection is it's ability to learn and adapt. It does not do this in open loop so by making the motor think it's cold all the time you are fixing it in stupid mode. No more adapting to elevation oe weather changes, No more modifying fuel trims based off closed loop inputs. It's like giving the ECU a lobotomy.
I also question if it even works and if so on all or only some 4As. My GZE has a 4 wire O2 so it's different than the older NAs but my car switches into closed loop about 20 seconds after I start it. Just needs enough time to heat the O2 sensor and it's good to go.

Whatever the case if I can make one suggestion to you. How much someones suggestion sways your belief or opinion should be directly related to the research they have done and the data they have provided. People make wild ass claims all the time and 90% of the time they have done no research to quantify it or prove their theory.

Here is an example. The ECU changes open loop fuel trims based off closed loop O2 sensor readings so some of my friends, customers and myself have seen modifications having the opposite effect expected. You loosen the AFM door and the ECU thinks more air is coming in so it adds more fuel. Now through the O2 sensor it sees it's running too rich so it leans things out. The ECU uses this data to lean out the open loop bins. It appears the ECU relies more on those trim tables than AFM values at high RPM in open loop so by trying to make it run richer we have noticed a tendency to go even leaner in high RPM open loop over time.
You need a way to monitor it and any one who doesn't has no business digging this far into their system.

Thanks for the Information, I agree a Wideband Fuel/Air Guage would be a wise investment!
I am unsure exactly what Cam Size/Compression Ratio, other than that they are aftermarket than stock.

And my 4AGE 16v has no 02 Sensor that I know of, Maybe because it is an aftermarket Header??
I am unsure if it is in Open or Closed loop, but it seems to run the best with the TPS Unplugged as well.

Maybe your right, it is actually a Leaner Mixture that im looking for... (Explains why Acceleration would feel Slugish)

I am willing to sacrafice some of the Adaptability of the ECU if I can get noticibly better Performance at the Track.

So is the Potentiometer Mod really a bust???

HachiRoku 86 wrote:And my 4AGE 16v has no 02 Sensor that I know of,

Is this a USDM motor? If so it should have an O2 sensor. If it should have an O2 then this should be your first and highest priority
If it's one of the EDM motors or whatever with no O2 then you should jump straight to getting a wideband and see what it says.

HachiRoku 86 wrote:I am unsure if it is in Open or Closed loop, but it seems to run the best with the TPS Unplugged as well.

This is another issue you should address before worrying about performance tuning.

HachiRoku 86 wrote:Maybe your right, it is actually a Leaner Mixture that im looking for... (Explains why Acceleration would feel Slugish)

Could be rich, could be lean, could be perfect. No way to know without the right tools.

HachiRoku 86 wrote:
I am willing to sacrafice some of the Adaptability of the ECU if I can get noticibly better Performance at the Track.

It is very unlikely you would. Going back to my lobotomy analogy. Would you expect better performance out of a track runner if you gave them a lobotomy?

HachiRoku 86 wrote:So is the Potentiometer Mod really a bust???

No, my point was that it's not as simple as people make it out to be and the ECU is also not as stupid as people assume.
There is a lot you can do to tune on the stock ECU. You just gotta know what is going on first so you can plan a strategy that will be effective.