Autotap grams of air per second???

BKB

Registered User
It would be nice if it just told you the MAF voltage but no it needs to use grams per second of air entering the motor. My EEC Tuner uses KG/HR. When i do the conversion it dosent add up. Is the autotap saying the motor is injesting .9 grams of air per second for every cylinder? If that is true i get 3.24 kg / hr this is way to low for my MAF table but if i multiply that by 6 i get 19.44 and that sound correct to me. Any ideas???
 
AFAIK, the MAF is typically ingesting 5~7 grams per second @ idle.

  • 5 gps= 18.0 kph
  • 6 gps = 21.6 kph
  • 7 gps = 25.2 kph
 
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So why is my autotap putting a decimal in front of it, It says .9? Don't really care as long as i can make the correlation.
 
.9 gps per cylinder = 5.4 gps = 19.44 kph for the engine, as you've noted ....what's the issue? Seems like that would be an acceptable value.
 
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I will check grounds, i used to have a bunch of extra grounds and recently removed them. Car has no codes so i would think the MAF is alright. I have been using the same Pro-M for about 10 years now and havent dropped it or over oiled the filter. Do you happen to know what measurment the #s are in the desired air flow netral/drive( grams per second? ) ? Its been 5 years since i tuned and already forgot most of it.
 
I would say 'desired' numbers would be wholly dependent on your particular setup. It's just a reference - start to worry if it goes low, such as .1 or way high. Substitute another MAF for comparison.

>using the same Pro-M for about 10 years now


All the more reason to get those grounds back on there :)
 
.9 gps per cylinder = 5.4 gps = 19.44 kph for the engine, as you've noted ....what's the issue? Seems like that would be an acceptable value.

Somehow i missed this post. My first question was is the .9 grams per second per cylinder and should i be multiplying that by 6. I didn't know if that was the way to do it. I know that 19.44 K/Hr sounds about right for idle, i belive my old set up was around 24k/Hr but the motor has been totally reworked. Its not really that easy to swap out my MAF and the MAF reading is increasing with RPM so i would think its working as it should. That and i haven't had to drastically change my tune to make the car run. Idle is giving my some problems now but im going from a Ford Next Gen Star tester to this Autotap and i don't like the way the Autotap displays things.
 

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>Somehow i missed this post.

Sorry, I was editing. My bad :)

>Idle is giving my some problems now

>the motor has been totally reworked

You do know how to perform the EEC 'relearn' procedures, right? And how you can expect things like 'idle' issues until the EEC finishes (re)mapping out all the sensors?

>Its not really that easy to swap out my MAF

Tap on it while the engine is running and see if it throws any codes or bounces the gps reading. Did you perform any wiggle tests on the connectors/harness when you checked for codes?
 
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Wow...that photo reflects quite a bit of work :)

There was a guy here recently that had a no-start after a rebuild...turned out to be the freshly painted accessory bracket was inhibiting the DIS ground path.

I'm sure you've taken care, but I'd still remind you to verify all grounds/ground paths carefully, free of any assumptions, just to be safe.
 
I force OL all the time so no short or long term fuel trims to worry about. I do this to get better MPG, old motor was a tad over 350rwhp on a mustang dyno and got 25mpg with mixed driving. In the 10+ years that i have been tuning this car i haven't experienced any other form of relearning. Just went out and tried the autotap on my 02 escape and it also came up .9 at idle but it says lbs/hr and that just makes no sense at all.
 
Might be time to query the AutoTap techs directly :)

Good luck - sounds like a nice car.
 
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MAF info presented to you is software based as the EEC uses a/d ticks per second in our cars. Just to be safe, I'd actually measure voltage right off the maf just to see where you are at in your MAF table so you can figure out the right conversion.

If your running open loop all the time then I assume your using a Wideband O2. You should be monitoring short fuel trims (LAMBSE's) as those will show you your commanded AFR for open loop conditions. Long term fuel trims or adaptive fuel trims are not learned during open loop times, but are applied when running in Openloop if any have been learned.

Honestly though, there is no reason to be running your car totally in open loop unless all you do is race it. If all is well on the car, close loop will get you the best mpg you can get. I've tuned my car and I can get 30mpg now on the highway at cruise while she's running closed loop (well used to, as my cats are shot).

As an example of changes to the car and affecting fuel mileage, if you've dropped to a 180 tstat in the car, that actually drops below several temperatures of how fuel is managed, spark is managed, dashpot functions and accel enrichment functions etc, which will drop your mpg because the car is simply not getting hot enough according to the computer.

Frit
 
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what started me running im OL was a mechanical problem that caused bank 1 rich bank 2 lean. This would max out the adaptive and cause the motor to run like crap. After swapping O2s, and injectors from one side to the other with no change i assumed poor valve job. But running the car in OL i was able to run the car with no problems excellent drivability and great MPG for 350rwhp. No way running my car in CL will get better MPG then me running in OL at 15-16 AF. I can run this car very lean with no drivability issues. After running my old motor for about 5 years running 12.5 AF at 16psi and 16 AF at idle and light throttle the motor was in great shape, valves were all shot do to shady machine shop. The first year i ran 13.5 AF at full boost with no detonation. It was weak but no pinging and no damage to the hypercenetic (sp) pistons. I learned that an EGT meter is not the best tuning device.
 
Wow!!! I would have to say that you have the only motor in this club that can run that lean without blowing up, that I know about anyway.

Obviously, your setup is totally different then so please disregard what I said.

Sorry

Frit
 
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what started me running im OL was a mechanical problem that caused bank 1 rich bank 2 lean. This would max out the adaptive and cause the motor to run like crap. After swapping O2s, and injectors from one side to the other with no change i assumed poor valve job. But running the car in OL i was able to run the car with no problems excellent drivability and great MPG for 350rwhp. No way running my car in CL will get better MPG then me running in OL at 15-16 AF. I can run this car very lean with no drivability issues. After running my old motor for about 5 years running 12.5 AF at 16psi and 16 AF at idle and light throttle the motor was in great shape, valves were all shot do to shady machine shop. The first year i ran 13.5 AF at full boost with no detonation. It was weak but no pinging and no damage to the hypercenetic (sp) pistons. I learned that an EGT meter is not the best tuning device.

Excuse me for jumping in here, but how do you do all this? Can you point an absolute dunce in our engine management system to somewhere I can get some information. I am running a stock, daily driver 92SC (OBD1) and would love to see some of those fuel economies. I understand A/F ratios, etc., as a matter of fact, I am a retired automotive engineer, but way before the electronic age.

Specifically if an EGT meter is not the best tuning device, what is? Also how do you get the system out of closed loop and control the A/F ratios?
 
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Im running an OLD EEC Tuner that alows me to change alot of perameters with a laptop. For tuning i use the EGT, Autotap, and LC-1 wide band O2 sensor. For my computer an EEC=V there are many options to tune, SCT, EEC Tuner, Tweeker, AutoTap, and probably 5 more.
 
Im running an OLD EEC Tuner that alows me to change alot of perameters with a laptop. For tuning i use the EGT, Autotap, and LC-1 wide band O2 sensor. For my computer an EEC=V there are many options to tune, SCT, EEC Tuner, Tweeker, AutoTap, and probably 5 more.

I don't think any of these support my 92SC (OBD1).
 
All SC's use the EEC-IV unless retrofitted to run with an EEC-V, and there would be alot of pain to that conversion.

If your interested in tuning, you can use the old EEC Tuner, but there is much more modern hardware and supporting software that allows you to tune your car more accurately, such as SCT, Tweecer, and Moates. The EEC Tuner is limited and you need to "scale" everything because not all the parameters are available to tune with it.

While BKB can run his setup lean like that, that is not a recommended practice for a forced induction motor especially if your daily driving it. AFR is just as important to keep your valves cooled as well as emissions control. It is general practice to target an AFR of 11.7 for forced induction motors running pump gas at high RPM WOT conditions, and around 12.3 or so for N/A motors. While cruising, having the O2 sensors working (closed loop) and keeping the AFR around the 14.7 to 15.3 which is what its designed to do is about where your going to get your best balance of mpg, emissions, and valve temperatures (as well as a few other things).

For that gain of a mpg and a couple of rwhp I'd honestly have to say its not worth the risk to run that lean for most people.

ps: this is not meant as an attack against BKB. I'm just stating what is out there and the industry standard way of tuning so to speak.

Frit
 
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All SC's use the EEC-IV unless retrofitted to run with an EEC-V, and there would be alot of pain to that conversion.

If your interested in tuning, you can use the old EEC Tuner, but there is much more modern hardware and supporting software that allows you to tune your car more accurately, such as SCT, Tweecer, and Moates. The EEC Tuner is limited and you need to "scale" everything because not all the parameters are available to tune with it.

While BKB can run his setup lean like that, that is not a recommended practice for a forced induction motor especially if your daily driving it. AFR is just as important to keep your valves cooled as well as emissions control. It is general practice to target an AFR of 11.7 for forced induction motors running pump gas at high RPM WOT conditions, and around 12.3 or so for N/A motors. While cruising, having the O2 sensors working (closed loop) and keeping the AFR around the 14.7 to 15.3 which is what its designed to do is about where your going to get your best balance of mpg, emissions, and valve temperatures (as well as a few other things).

For that gain of a mpg and a couple of rwhp I'd honestly have to say its not worth the risk to run that lean for most people.

ps: this is not meant as an attack against BKB. I'm just stating what is out there and the industry standard way of tuning so to speak.

Frit

I wasn't interested in changing the boosted A/F, but it is my understanding that the stock setup sets cruise to about 14.7 which I believe is too high, with 15.3 being more fuel efficient. Also, apparently E10 is fooling the EEC to add more fuel. It would be interesting to verify that and change it.

The web sites for the tweecer and others specifically say that it only works on 1996 and later OBDII systems. Is this untrue?
 
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