1G tuning on S-AFC

[abakja1]

http://dsmhawaii.com/uploads/abakja1/Ft2.png

Im beginning to tune today and read most archives at DSM archives, RRE, and others listed on DSMTuners that I could find on tuning as this is my 1st time at it

I just started wanting to tune my Low pts at 1, 2, 3, and bout 4k RPMs and logged RPMs, O2 trim, and my Low Trim on my laptop using TMO software,

I have 550cc, 190 Walbro pump, 3" intake on 1G MAF without lower honeycomb, screw backed out and KN filter w/ no cover (enough to know for now as Im doing baseline adjustments at idle in garage),..

So my question is, how long does it take for Low trim to make any changes once I make fuel changes on S-AFC? Ive read like 5-10 seconds, but I was sitting at 1k after each +5% increment adjustment) for at least 30 sec or more with no changes at all...Looking at RRE lit, they had 1K at +50%,..I went all they way there with no change at all,.

My base LFT is at 119% which means I am running too lean, so I made adjustments in 5% increments from 0-50 on the SAFC and there was no changes in the LFT at all,..The oxygen feedback trim did oscilate from 145% (at the start) to 60% as I added up to 50% fuel then it did level out to 100%. But my LFT did not budge at all,...

Im wondering if having that 3" intake to the turbo creates such a lean condition at idle that the SAFC will make no changes at all,..After doing this for like 10 minutes, I had enough till I get more info, so I didnt even bother idling at 2, 3k and doing any changes,..

Sorry if this is like another "please help me" question,..but I do want to learn somewhat on my own on our cars and stop having to rely on other's "hands on" help, and just get anyones gracious written help if they could,..

thanks
Kevin
1990 Mitsu Eclipse GSX

 

[gsxtacy]

I am not too familiar with LFT's.

I usually set the SAFC to the ones closest to my setup from RRE, and worry about the HFT's.

Where I am at when power is the main concern.

Why not just set them to -18% correction and let the ECU map your low settings?

I am open for discussion if this is not a good practice cause like I said, LFT's are not my specialty.

GSXTACY

 

[kpt4321]

Don't just set them to -18%.

You're right, they will take a LONG time to change. It's a pain, but you just get used to it.

Try tuning by getting the STFT and the LTFT to cancel each other out; that is, if the LTFT is +130%, then get the O2 trim around 70%.

Once that is close, then reset the ECU. Pull the lower right fuse in the driver's footwell, and wait a little bit. Then when you put it back in, the fuel trims will all be reset to 100%. Once they are like that, if you tune quickly you can tune using the O2 trim only. That makes life much easier.

You'll probably end up at like +15% or more at 1k rpm, that's normal for a hacked 1g MAF.

Try this:

http://home.comcast.net/~tarryo/kyle/tuning.html

OR

http://users.wpi.edu/~ktarry/dsmtech/tuning.html

 

[slowblacktalon]

Are you tuning your LFT on low or high throttle. You have to set the afc to read low throttle as 0% and hi throttle as 1% and up. This way your LFT will be changed at idle. If you try to tune the LFT without success this is usually the cause of it. The only other thing you can do is to tune with a 3 bar map sensor and wire it in to your afc. That is getting complicated though.

-Brett

 

[slowblacktalon]

Oh yeah also make sure the engine is at normal op. temp. This will also make the trims change. It should change within 15 seconds.

-Brett

 

[kpt4321]

Originally posted by slowblacktalon
Are you tuning your LFT on low or high throttle. You have to set the afc to read low throttle as 0% and hi throttle as 1% and up. This way your LFT will be changed at idle. If you try to tune the LFT without success this is usually the cause of it. The only other thing you can do is to tune with a 3 bar map sensor and wire it in to your afc. That is getting complicated though.

That's a shitty idea, don't do it.

Set the throttle points correctly (around 20 and 60 usually works well) and tune it correctly. There's no reason to ghetto it out.

 

[Cirus_93TSI]

yea, setting the TH points to 0% low and 1% high is a horrible idea, then you would have the same fuel map regardless of weather your cruising or running it. iv know people to set the low to 0 or 1% and the high between 70 and 99% on turboed hondas to get a curve that runs good, but the high has to be above around 50%.

 

[kpt4321]

I don't think you want to set the low down that far, go with at least 10%. There's no reason to interpolate at idle.

 

[tsi20gawd]

0% low and 1% high is a VERY easy way to tune.....
if you dont know why that is then dont post you dont know what your doing.

oh and one more thing if you think that someone elses"tune" is going to work for your car you have to learn A LOT more about tuning than you think!!!!

If you have a "legit" question about "tuning" or specifics about using a M.A.P. sensor (yes a map sensor) to run your afc p.m. me.

if your just some post jockey dont wast ANYONE elses time.
thanx and hope ya' dont get bent out of shape.

 

[nine5raptor]

Originally posted by tsi20gawd
0% low and 1% high is a VERY easy way to tune.....

And also pointless. Why would you want the same high/low settings? If you're gonna tune like this, you might as well skip the afc and just put a pentiometer in the baro wire.

 

[tsi20gawd]

how is that "pointless"
so imagine this ..if you will
your the ecu all is stable then all of the sudden your airflow signal starts
"bouncing" between two completely diffrent sum's at a specific rpm break the ecu tries to "tune" that out. The whole time your ecu is trying to tune for "effienciency" while your dicking with the signal.
now imagine this.
same situation however the afc is no longer TPS dependant
your "low" map is strictly low boost no bouncing of the maf signal just stable smooth readings that the ecu can accomodate.
your "high" map is strictly high boost
so the only time your maf signal "bounces" is when you hit lets say 17 psi then the ecu simply sees this as an aiflow change and acts accordingly the less you "interupt" the maf signal the better the car runs and the more stable it stays tuned.

simply stated:
the less you trick the ecu the more stable your tune.
just so you know I tune my car by burning new eproms

 

[kpt4321]

First, go read my post here:

http://www.dsmtuners.com/forums/showthread.php?s=&threadid=98804

Now, let's discuss your post, shall we?

Originally posted by tsi20gawd
your the ecu all is stable then all of the sudden your airflow signal starts "bouncing" between two completely diffrent sum's at a specific rpm break the ecu tries to "tune" that out.

Why the hell would your ECU be "bouncing" between two cimpletely different "sums." (You know that a sum is the result of an addition operation, and that no such operation is taking place with the SAFC or the ECU's airflow signal, right?)

This makes no sense at all. The airflow signal does not "bouce" around, nor does the ECU try to tune something out.

The whole time your ecu is trying to tune for "effienciency" while your dicking with the signal.

Again, what the hell does this mean? In closed loop, the ECU wants 14.7:1 Air:Fuel ratio. It's that simple.

same situation however the afc is no longer TPS dependant
your "low" map is strictly low boost no bouncing of the maf signal just stable smooth readings that the ecu can accomodate.

No. Your low map would not be strictly low boost if the throttle point was set to 0%. Your low map would only work at idle, any other times it wouldn't be active.

your "high" map is strictly high boost

No, with the TPS point for the SAFC hi map set at 1%m the high map is all the time.

so the only time your maf signal "bounces" is when you hit lets say 17 psi then the ecu simply sees this as an aiflow change and acts accordingly the less you "interupt" the maf signal the better the car runs and the more stable it stays tuned.

It is apparent that you do not understand how the SAFC works, and probably also do not understand how the air metering works. I don't know what they hell you're talking about with airflow bouncing, airflow sum, or stability. How about you step back and think about what you DO know, and then I can help you to understand it from there.

simply stated:
the less you trick the ecu the more stable your tune.

Not necessarily.

just so you know I tune my car by burning new eproms

So do I. Your point?

 

[tsi20gawd]

what?
yeah in closed loop it does tune for 14.7
and the input signal does bounce at that chang point because your changing it(depends how far apart thrtl points are).
quit simply THE BEST WAY to run a afc is with a map sensor PERIOD.
there is absolutly NO reason to have your afc changing your fuel map by the TPS actually I dont know how you can even keep the damn thing from knocking that way.
what size turbo do you have?...umm never mind its tiny thats why it works for you.
tell you what get a bigger turbo and tune it your way by tps then tune it my way map see what happens then.
have you ever even been in a car with a big turbo?
are you guys seriously arguing about tuning a damn 14B?
uuhhhhh have fun!!!
oh yeah and if you dont see the benifit of using a map sensor to control
your afc SELL YOUR CAR!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

eproms make life esier dont they

 

[tsi20gawd]

just figured id throw this up there just in case

Its pretty simple, instead or using your TPS for the "throttle point" on your S-AFC, you simply use a GM map sensor. A map runs on a 5volt system just like a TPS, so you simply use the GM map as your "throttle point" signal. The wiring goes as follows:

wiring the GM map sensor 1-3 bar

pin-A ground---
pin-B sensor output(grey wire on your safc)---
pin-C +5volts.

use a multimeter, disconnect the "tps" plug, turn the ignition "on" check the wires for about 5 volts"voltage may vary slightly"(on a 91-94 I know its the green wire red stripe). simply use a wire tap from the 5 volt tps wire to the pin C on the gm map sensor, there is your 5 volt power in.Ground pick one! does'nt really matter as long as you Ground it!. Output wire from the map, simply cut the "GREY" wire on the safc where it meets the "ECU". Connect the output wire from the map to this wire.

as far as tuning it i can only give you some advice, turn your S-AFC on to view only 1 perameter...throttle pos. If you have played w/your S-AFC a little your know there is a "peak hold" function turn this on while on the throttle pos srceen. Now this is where its gets tricky, Boost is now throttle position, so make a pull in LOW BOOST, see what your maximum throttle position is. This is your LOW BOOST, tune HIGH BOOST the same way.

this what my throttle points look like on my car using a GM 3-Bar map

low87% high89% low boost is 17psi and high is 22psi.

if you have any other questions dont hesitate to ask and good luck!


heres a useful site on GM sensor info!:http://www.diy-efi.org/gmecm/component_info/sensors.html

so here ya go this about the simplest way to explain it.
just to let you know "slowblacktalon" is running his afc this way also
if you have not even tried this yet DO IT you will like it alot it helps get rid of quite a bit of part throttle knock.
cheers

 

[nine5raptor]

Just curious, how do compensate for the fact that the afc is constantly changing what it sees as 100% throttle? Everytime you change your boost, your hi/low points just changed as well as the afc now has a new '100%' value to base its percentages off of. Do you just retune it all?

 

[kpt4321]

You don't give up, do you?

You're stepping on the wrong toes, and this may get ugly.

Originally posted by tsi20gawd
and the input signal does bounce at that chang point because your changing it(depends how far apart thrtl points are).

It DOES NOT bounce around. The whole point of the two different load maps is so that you can set the throttle points apart, and the SAFC will interpolate between then. Thus, the corrections do NOT jump around, and neither does the airflow signal. It changes linearily.

quit simply THE BEST WAY to run a afc is with a map sensor PERIOD.

I agree 100%, and that is why when I had a SAFC I always ran it with a 3-BAR MAP sensor. However, that is not the issue at hand. Your original suggestion was to put the throttle points at 0% and 1%, which is flat wrong. That is the issue.

there is absolutly NO reason to have your afc changing your fuel map by the TPS

The fuel maps need to be indexed by load, unquestionably (if you have more than one map). The TPS is a very good indicator of load on non-turbo cars, which is probably what Apex-i has in mind when they designed it. Additionally, they had to use a sensor that every car had (TPS), unlike a map sensor which not every car has.

When used on a turbo car, you still want to indicate load. As it turns out, MAP is a better indicator of load than TPS, so everyone with a SAFC should consider switching over. However, TPS reference is still better than no reference at all, which is what you were (incorrectly) suggesting.

what size turbo do you have?...umm never mind its tiny thats why it works for you.

Would you like to quote me where I said that I was running a SAFC with throttle reference, or even better, where I said I was running a SAFC at all? I'm doing neither, so you're dead wrong.

Once again, you're going off the topic at hand. The topic is your suggestion to run 0% and 1% throttle points. It's wrong. End of story.

oh yeah and if you dont see the benifit of using a map sensor to control
your afc SELL YOUR CAR!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I suggest often that people switch to MAP sensor based load switching. If you search here, you'll see threads about it. Would you like to tell me where I said that people shouldn't.

Although I've said it a few times already: that is not the topic at hand. You suggested setting the throttle points to 0% and 1%. I corrected the error. It's that simple.

 

[kpt4321]

You don't need to post how to do the MAP mod, it has been covered before. Lots of people run it.

as far as tuning it i can only give you some advice, turn your S-AFC on to view only 1 perameter...throttle pos. If you have played w/your S-AFC a little your know there is a "peak hold" function turn this on while on the throttle pos srceen. Now this is where its gets tricky, Boost is now throttle position, so make a pull in LOW BOOST, see what your maximum throttle position is. This is your LOW BOOST, tune HIGH BOOST the same way.

No, you don't want to do that.

You want the low throttle point to sit around 10in-Hg of manifold vacuum, or in that area at least. That way, when you start to load the motor (higher speed highway cruising, uphill, etc) it starts to interpolate. Then, you set the high throttle point somewhere in boost, probably a little bit below your max boost level.

this what my throttle points look like on my car using a GM 3-Bar map

low87% high89% low boost is 17psi and high is 22psi.

And you wonder why your corrections are bouncing around? You're giving the SAFC a freaking 2% range to interpolate in. NOT a good idea.

Do you even understand how corrections and load work?

if you have any other questions dont hesitate to ask and good luck!

Where do you come up with this crap?

so here ya go this about the simplest way to explain it.
just to let you know "slowblacktalon" is running his afc this way also
if you have not even tried this yet DO IT you will like it alot it helps get rid of quite a bit of part throttle knock.
cheers

Maybe you should try setting the load points correctly. You might be surprised.

How different are your low and hi maps in terms of corrections?

 

[kpt4321]

Originally posted by nine5raptor
Just curious, how do compensate for the fact that the afc is constantly changing what it sees as 100% throttle? Everytime you change your boost, your hi/low points just changed as well as the afc now has a new '100%' value to base its percentages off of. Do you just retune it all?

Nobody is 100% sure about how that works, but as far as I know:

The SAFC is pretty liberal with where the 0% throttle point is, but not nearly as liberal with the WOT point. This is because from and engineering/design standpoint, you can pretty much asume that the car will see 0% throttle quite often, but you have no clue how often it will see 100% throttle. Thus, 0% throttle can be simply defined as the lowest signal the SAFC sees, but full throttle can't necessarily bee defined as the highest.

When I was running a SAFC with the MAP mod, even after months of use the full throttle point never came all the way down to the maximum setting that the SAFC would see. I think it came down a little (I am not 100% sure at this point), but I am sure that it never came down all the way.

You just have to set them initally to what you think will work (usually like 10-15% and 60%) and then watch the peak-hold to see what it does. It's easy to do.

 

[abakja1]

Anyways,...

thanks for trying to help me out with my th pts and me trying to add/subtact fuel for my car with the S-AFC,..

but I cant do any logging until I get another laptop for on-road driving,..My laptop only works right now with an outlet as its battery is crap, so i can only tune in the garage.

My car was at operating temp and the Low fuel trim didnt budge at all,..the O2 trim did go down as I added fuel and leveled out to 100% after a minute or so, but I thought I can only make fuel adjustments for 1, 2 ,3k etc by looking at the LFT which is at 119% right now, so I added fuel at 1k to 15.

---Try tuning by getting the STFT and the LTFT to cancel each other out; that is, if the LTFT is +130%, then get the O2 trim around 70%.----

This part I dont understand, I know that adding fuel with lower the o2 trim, but what does the 02 % mean at 70%? The O2 trim levels out to 100% anyways so how do I know if I added enough fuel and cause the LFT hasnt moved at all?

So, in all frustration, I just went by RRE's settings on their website for the 1G and I got fuel cut at about 4.5k to 5k rpms,...I thought those setting was ok as it added fuel anyways and my car did run smoother at idle, but I guess Im too rich which I originally thought I was doing (black residue on my rear bumper above exhaust), but the RRE setting had fuel added at all rpms,..

I have a 90 GSX with 2g pistons, Evo 16g ported and at 15psi (for now as Hawaii is like 83 deg always) on pump 92 octane, FMIC, 2 1/2 UICP, LICP, 190 walbro, rewired fuel pump, RC 550s, 3" intake with KN and honeycombs out, screw backed out, ported intake manifold and Evo exhaust manifold, ported intake/exhaust head, 2 1/2 exhaust no cat,...

any more suggestions? I would like to tune with my Palm, but heard the cable for a Palm from car's diagnostic to hotsync cable differs from a cable from the diagnostic to a laptop. Wiring is different at the DB9 end at pins 2 and 3 (should be switched) and if I use my cable for my laptop to my Palm, I may short the cable out (as experienced by a DSMTuner member and a local club member here in Hawaii too,..) I dont want to do this as I just need to borrow a laptop from someone,...But dont know who yet,..

thanks
Kevin

 

[nine5raptor]

Originally posted by abakja1
So, in all frustration, I just went by RRE's settings on their website for the 1G and I got fuel cut at about 4.5k to 5k rpms,...I thought those setting was ok as it added fuel anyways and my car did run smoother at idle, but I guess Im too rich which I originally thought I was doing (black residue on my rear bumper above exhaust), but the RRE setting had fuel added at all rpms,..

honeycombs out, screw backed out, ported intake manifold and Evo exhaust manifold, ported intake/exhaust head, 2 1/2 exhaust no cat,...

Having modified the mas, the settings given by rre are going to be wrong, as your mas is now calibrated differently.

 

[kpt4321]

Originally posted by abakja1
My car was at operating temp and the Low fuel trim didnt budge at all,..the O2 trim did go down as I added fuel and leveled out to 100% after a minute or so

Like I said, just reset the ECU (once you have a logger). That way, all the fuel trims (lo, mid, hi) will be reset to zero, and you can just tune to get the O2 trim at 100%.

but I thought I can only make fuel adjustments for 1, 2 ,3k etc by looking at the LFT which is at 119% right now, so I added fuel at 1k to 15.

No. The low fuel trim really only applies to idle. The mid fuel trim will apply as slow light cruise speeds, like 1.5k-2.5k rpm, give or take. The high fuel trim applies at higher cruise speeds, like on the highway.

You'll get it base tuned, and then when you look at the logger a week later they will have moved around a little. You just have to change the settings accordingly, and you'll get it set eventually.

This part I dont understand, I know that adding fuel with lower the o2 trim, but what does the 02 % mean at 70%? The O2 trim levels out to 100% anyways so how do I know if I added enough fuel and cause the LFT hasnt moved at all?

If it is at 70%, that just means that it's trying to lean the car out 30%.

So, in all frustration, I just went by RRE's settings on their website for the 1G and I got fuel cut at about 4.5k to 5k rpms,...I thought those setting was ok as it added fuel anyways and my car did run smoother at idle, but I guess Im too rich which I originally thought I was doing (black residue on my rear bumper above exhaust), but the RRE setting had fuel added at all rpms,..

See, that's why you need to tune the car individually.

Also, have you pressure tested for boost leaks? That's a BIG factor in tuning, do it before you even try.

Did you read that guide that I linked you to?

 

[abakja1]

Yes,.thank you,..I did read and print out the links you posted, I have those and countless others to help me tune when in my garage due to my crappy laptop. I did a lot of searches and research before I started this post, and Im still confused as I am a basic tuner (just starting),..Im sure Ill get better the more I experiment and pass on my knowledge and experience to others.

I will do a boost leak test when I get a hold of someone at my local club to let me borrow the boost leak cap,.Im pretty sure no leaks, but just to make sure,..

And even though I am adding fuel am I right in doing this since I got the 550's and 190 lph and rewired pump for my Evo 16G? Am I going in the right direction with added fuel across the board from 1 to 72k?

Kevin

 

[kpt4321]

I can't guarantee anything without a logger.

 

[nine5raptor]

You should be subtracting fuel, not adding.

edit: Ignore me, go with what kyle said.

 

[abakja1]

Yup,..

Set all my rpm pts back to 0 and the car is better driving (blasting around rich still though) with more timing I guess,..I guess Im SOL till I get my hands on a laptop,..

Kevin