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Old 02-12-2001, 07:08 PM   #1
inzomniak
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Question Is this True?

"Don't get one for the MY00-01. The computer learns that you have one and will cancle the settings out after a little while. It was the biggest waste of $300 I've ever spent because I always have it set to 0% even with my nitrous!"

I got the S-AFC for my car as well, but I have yet to install it on my car... if the settings reset after a while then I see no point in taking the thing to dyno-tune at Minnam/Tecknik afterall
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Old 02-12-2001, 07:09 PM   #2
rpone605
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i'm gonna lean towards yes due to the map sensor having it's own fuel maps...i believe is the correct way to say it.
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Old 02-12-2001, 09:33 PM   #3
North Ursalia
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<FONT face="Comic Sans MS">Another reason being that the MY00-01 run rich as opposed to lean with an intake, ergo, there is no need to bump the amount of fuel at a given rpm range.

Brian

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Old 02-12-2001, 10:40 PM   #4
inzomniak
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So basically you are telling me that... for a MY00 2.5RS, the Apex'i S-AFC will provide no use for me even if I have an intake and catback exhaust?
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Old 02-12-2001, 10:43 PM   #5
Penphoe
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Well, if in theory the MY0x's run rich, you could use the SAFC to lean out the fuel going into the engine to make a bit more HP. That's in theory though.

LaterZ!
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Old 02-12-2001, 11:12 PM   #6
inzomniak
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Well how about in actuality Darren? hehe
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Old 02-12-2001, 11:50 PM   #7
Eric SS
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Since I am the one who posted the quote above, I can tell you for a fact that it is true

Eric
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Old 02-13-2001, 09:54 AM   #8
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Eric,
Base on your experience, if I use the SAFC to lean out '00 RS, will there be some HP gain?
Thanks~
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Old 02-13-2001, 10:14 AM   #9
adamsrs
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So I wasted $300 dollars? Oh well it still looks trick as ****!
adamsrs www.unnatural.org
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Old 02-13-2001, 10:34 AM   #10
Prog
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ive always thought a SAFC on an N/A car with regular cams was a waste of money

at least on the honda/acura world, unless you have wilder cams, and other n/a work done. You will gain nothing from tuning a stock n/a car with a SAFC... (in H/A's)
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Old 02-13-2001, 11:57 AM   #11
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no due to the auto learn feature which will compensate
Quote:
Eric,
Base on your experience, if I use the SAFC to lean out '00 RS, will there be some HP gain?
Thanks~
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Old 02-13-2001, 03:41 PM   #12
inzomniak
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Yeah right?

Cause I saw the dyno charts for Keiho's car.... he has an exhaust, upulley, and intake...

it pulls significant harder with the addition for his Field SFC...

Isn't the SFC and the S-Afc the same thing?
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Old 02-13-2001, 03:51 PM   #13
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my MY00 runs rich under 3500rpm, and lean above that (only have catback exhaust, no intake yet)

i don't think my ECU has learned anything yet (had it for 3 month now and put on about 3k miles since), but i'll do a couple runs tonight or tomorrow to see if that's true
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Old 02-13-2001, 05:17 PM   #14
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Since my name was mentioned here I'll throw in my 2 cents.

When my car was turbo'd I was using the Hyper R as my only means of controlling fueling. It worked great up until the top end, which by then my Hyper R ran out of numbers! I was enriching the maximum 30% and it still wasn't enough. Anyway, after a while of testing on the dyno, the guys at Technik found that YES, the ecu did revert back to its oem fuel maps and the Hyper R was useless after that. However, this is only the case when cruising and the throttle is at a constant level. So for what its worth, the Hyper R does work, but if you're on the highway and the throttle isn't moved much, yes the ecu does revert back to its oem fuel maps.

You can look at my dynograph to see the difference between my non-tuned NA setup and my Hyper R setup.

Last but not least, I'm using a Field Hyper R, so it might be different from the Apex'i SAFC
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Old 02-13-2001, 05:23 PM   #15
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So Keiho, are you saying that a turbo'd MY00/01 would be best served by going with a stand alone fuel management system (like TEC-II) and avoiding the stock ECU altogether?
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Old 02-13-2001, 06:27 PM   #16
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"However, this is only the case when cruising and the throttle is at a constant level"

Keiho, where you in close- or open-loop??
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Old 02-13-2001, 07:33 PM   #17
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the s-afc doesn't tell the ecu to add or take away gas, all it does is trick it into thinking more or less air is going into the engine, then the ecu regulates the fuel injectors. it's a pretty good thing to have for a turboed car, but as far as an n/a car goes, you can only yield a small amount of hp out of an hour or so of tuning with an a/f meter.
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Old 02-13-2001, 07:34 PM   #18
inzomniak
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So it does work, but if I keep it at a constant throttle then it will reset?

Is it easy to reprogram the original set of numbers?
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Old 02-13-2001, 08:39 PM   #19
P.K. Motorsports
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The ECU does not "learn" in closed loop (except from knock). There is no "fuel map" in closed loop. It constantly trims the mixture based largely on the inputs from the O<sub>2</sub> sensors. Playing with the SFC will do nothing in closed loop since the ECU instantly (not eventually) works around it and brings the mixture back to what it deems appropriate. If it senses knock the whole timing-retard regime is triggered and it may take a very long time for it to "unlearn".

In open loop the ECU only learns if it encounters knock. If this was not the case and it did take A/F mixture into account then O<sub>2</sub> meters (and in fact, the SFC itself) would be pointless, since the ECU would immediately override any settings you made as it does in closed loop. The fuel maps are preprogrammed, hence the term open loop. In a MY00 this means x injector cycle duty for y speed and z density (in a MY98-99 it means x injector cycle duty for y*z mass airflow). You can still trick the ECU by telling it that the density is from percentage of z.

You can lean the engine out with typically positive results if it was running too rich (as measured by an EGT gauge, and if possible in conjuction with an O<sub>2</sub> meter reading), but if you induce knock you are going to get yanked back by the ECU.

When you hear about dyno tuning with the AFC, what they are usually talking about is getting a feed on the O<sub>2</sub> sensor reading and overlaying it on the dyno graph, then looking for patterns and correcting accordingly.

Edit: can't spell

[This message has been edited by P.K. Motorsports (edited February 13, 2001).]
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Old 02-13-2001, 08:55 PM   #20
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Markus - of course if you have the money for a standalone engine management systems, yes that is the best for turbo'd MY00-01 cars. However, a RRFPR and a fuel computer would do nicely, you won't get the most power, but it'll work.

cj917 - I haven't the slightest clue, I'm just repeating what the mechanic at Technik told me.
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Old 02-13-2001, 09:00 PM   #21
cj917
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what smacksube and PKM said

silly me, got scared for a minute thinking that the SAFC would re-write the preprogrammed lookup table... of course not, since it simply tricks the ECU thinking it's seeing more or less input from the MAP sensor

for those who want more readings, here's wac's SAFC tech note
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Old 02-13-2001, 09:15 PM   #22
cj917
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keiho:
i'm guessing you were in close-loop then... wac (and someone else in the NE board) confirmed that the ECU enters open-loop mode of >20% throttle position... in that case, the ECU does not refer back to its stock fuel map, but simply relies on the o2 sensor's feedback for fuel correction (see PKM's post)

markus:
wac is running a turbo on his OBS using SAFC (and ITC i believe), but no TEC-II... and it's running great, to my knowledge... as long as you tune it carefully and have the necessary gauges to monitor things, it should be fine

and if you are not planning on TC/SC-ing the car, running lots of N/A mods that would drastically change the amount of air entering the engine, or simply using less than 25% of the throttle most of the time, yes the SAFC is a waste of money
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Old 02-13-2001, 10:03 PM   #23
P.K. Motorsports
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cj917 - the ECU goes into open loop at roughly 90% throttle based on O<sub>2</sub> sensor readings. It is in closed loop at all other times.
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Old 02-13-2001, 10:08 PM   #24
inzomniak
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Hehe... P.K., I don't really get it... simply put... what you told me is....?

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Old 02-13-2001, 10:19 PM   #25
cj917
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Question

PKM:
are you sure?? i just took a drive outside, with the SAFC settings to all zero's vs. the corrections... and with the corrections i only need to push 25-30% throttle to see that the SAFC is indeed working (i.e. instead of my EGT reading shooting up towards the 1500F's, it stays around 1400's like i want it)

i'm not entirely sure how WaC tested the greater-than-20% theory (i think it was based on his o2 sensor readings... i have a MY00 so i dont bother to hook the SAFC up with the rear sensor), but someone else confirmed on that number too... you might wanna ask WaC himself

and if anyone else can confirm the >20% or other numbers, please help us and speak up!

(on a separate thought) when someone goes to a shop and sometimes they tune it by sticking a o2 sensor into your exhaust pipe, isn't that reading off what's "after" the cat(s)? and i thought that suppose to be not as accurate?
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