Apexi Safc.

[rev210]

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Edited November 6, 2006 by rev210

[RyanN]

well i bought one from the slidewize auctions for $330, cant wait to install it. btw, is there anything else i would need before i get it tuned? ie: i was told i would need a boost controller (gated wouldn't matter would it?), anything else?

[pixel8r]

I bought an safc recently from a member on this forum.

Was told it was a safc2 but turns out its an safc1 (blue screen). Not too happy about that.

Anyway, what would be the real world differences between the safc 1 & 2? Is there any reason I should sell it again and get a safc2 instead?

I'm particularly interested in the extra load points, the knock sensor, and open throttle features of the safc2 but am not sure how much real world difference it would actually make.

I'm mainly just after a better AFR graph for better overall power and economy so will the safc2 do a much better job than the safc1?

[Mr Italy!]

I bought an safc recently from a member on this forum.

Was told it was a safc2 but turns out its an safc1 (blue screen). Not too happy about that.

Anyway, what would be the real world differences between the safc 1 & 2? Is there any reason I should sell it again and get a safc2 instead?

I'm particularly interested in the extra load points, the knock sensor, and open throttle features of the safc2 but am not sure how much real world difference it would actually make.

I'm mainly just after a better AFR graph for better overall power and economy so will the safc2 do a much better job than the safc1?

Wow thats a dodgy move!!

Well i believe the safc2 has more points for finer tuning, but really in the grand scheme of things i dont think the 2 will beat the 1 by all that much - and after you spend way too much time and effort selling this dodgy one, possibly loosing money on it, and then getting an safc2 - i'd say just stick with the safc1.

[pixel8r]

Wow thats a dodgy move!!

Well i believe the safc2 has more points for finer tuning, but really in the grand scheme of things i dont think the 2 will beat the 1 by all that much - and after you spend way too much time and effort selling this dodgy one, possibly loosing money on it, and then getting an safc2 - i'd say just stick with the safc1.

yeah i might just keep it. After all, I only mainly want it for improved fuel economy/efficiency across the rev range and hopefully more power as a result as well. Or to put it another way, all I want to do is keep the AFR graph on 12:1 all the way instead of below 10:1 as it most likely is at the moment. Smells of petrol when I stop the car normally.

I think the biggest difference with the safc2 is it has 12 tuning points instead of 8. It also doesn't have a knock sensor - it just has a knock monitor so you can see on the screen what the ecu already is checking. I'm pretty sure the safc2 doesn't change anything based on the knock readings - its just for your information.

So yeah thanks for the re-assurance. I think the safc 1 (blue screen) will do fine for me. As you can see in my avatar I drive a stagea - not looking for race-car performance, just a good compromise between power and economy. Hoping for 150-160awkw and will be happy with anything close to that. Also hoping for 12L/100km but will wait and see...

[rev210]

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Edited November 6, 2006 by rev210

[pixel8r]

the S-afc II comes in a blue screen too.

The knock readings come from the factory sensor input. No you can't change them. The readings are usefull to log against other parameters when road tuning.

Doesn't effect closed loop and operates above a certain throttle % so no fuel ecconomy gains.

The safc2 says "SAFCII" on the screen and has a round knob on the front whereas the safc1 (not gen1) just says "SAFC" and has 4 direction buttons and a 'prev' and 'next button. Just a FYI for anyone wondering which is which

The knock sensor signal would be useful if the safc could change its maps when it detects knock - to prevent users tuning the AFRs too lean using the safc. BUT the safc II does not do this so there really is no benefit in the knock monitoring feature other than to see if your engine is knocking or not.

People always get better fuel economy after tuning with a safc. Thats 50% of the reason people get them.

When cruising or just rolling (ie. closed loop) the ecu will do a pretty good job of keeping things economical so there's no reason to want to change AFRs at low revs.

The idea is to use the safc to tune your air-fuel graph to be a fairly straight horizontal line in higher revs on a dyno - which means that at higher revs the car will use less fuel (turbo cars tend to richen up at the top end when you up the boost).

So unless you drive around all day under 2000rpm or something, then yes you WILL have fuel economy gains. How much gain would depend on driving style and also how rich the car was running before the tune.

[rev210]

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Edited November 6, 2006 by rev210

[pixel8r]

Given what you have said about the knock reading so far I must say for you and others without the understanding of what it all means, it certainly isn't much use other than to give you a feature that looks pretty boring as a guage display for the most part. do a search for power FC knock values (it's the same thing) and read away.

Knock sensor is usefull to indicate a tune need because it gives you scaled knock 'values', these are usefull for people who know what they mean. Like me. So when I see values creeping up due to issues with fuel, altitude, toluene addtion (extra fuel) or other conditions I don't have to race back to a dyno to pay $150 to have someone retune my S-AFC II, I can simply apply some small changes in fuel correction in the spots it needs it because there is the very handy logging graph.

For users like me I don't need a knock sensor to help me stop tuning the car too lean because the world has been blessed by the wideband O2 sensor for our tuning convenience. On the other hand the knock sensor is so sensitve it gives a fairly good warning when a tune hasn't got enough safety margin in it for a batch of crappy fuel , perhaps a trip down from a higher altitude home where you had your car tuned or a freak heat wave etc. It would be nicer of course if the S-AFC II had the warning light output of the Power FC that you can set to whatever knock value you like but you can't have it all for $300.

'Good' fuel ecconomy doesn't occur at full throttle, thats called various levels of 'crap' fuel economy. It's like comparing poo for taste. My old gtst didn't improve even a tiny bit, it was a work car driven upto 30,000km a year with 'fuel ecconomy' as a secondary goal. I never noticed at the drag strip either. Mind you I could be totally incorrect, you see I don't have 30+ tested accurately measured fuel consumption tests to make a statistically valid fact of it. But, when you are really after fuel ecconomy I recomend the latest in right foot technology not the S-AFC. Ecconomy or power choose one.

My point was basically that the knock sensor on the safc isn't really a sensor - its just passing on info that the ecu already collects. Not sure if there are any other devices to give you this info. Or you could plug a laptop into the ecu and read the info that way.

I'm sure if you know what you're doing it would be useful but in my case that kind of info is something the tuner would need, not me. And the tuner has a dyno and AFR graphs, and other tools to help with the tune.

If your tune doesn't have enough safety margin for a batch of "crappy" fuel, then that doesn't sound like a safe tune. Either way the ecu should still overcome most of this. The knock sensor in the ecu still works, so I assume it would still retard/advance timing etc as necessary. You're only "bending" the afm signal, not overriding it completely like with a pfc or something.

I cant see how people can deny an improvement in fuel economy with the safc. If your AFR graph is tuned to lean out the mixtures a bit at all revs above say 2500-3000rpm then provided you dont drive everywhere at under 2500rpm or with your foot to the floor, then you are going to save money. Sure your fuel economy may never be "good" but it will be better than before the tune.

If you dont see an improvement its probably because your AFR graph was already good and so it wouldn't have required much alteration via the safc. But guaranteed if you put an exhaust on your car and/or raise the boost above stock, its going to run richer at the top end as the stock ecu keeps pumping fuel in to avoid it running lean.

For me, I have my previous AFR graph on a dyno printout so I know it runs rich. And now I have a 3" full exhaust and more boost so that only makes it richer again. Its likely to be close to 10:1 at the top end so pulling that back to 12:1 right across the board is a big change and will give good results. Others have seen a 1-2L/100km improvement and up to 20rwkw extra just from installing a safc.

[rev210]

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Edited November 6, 2006 by rev210

[pixel8r]

The S-AFC is set to alter the fuel based on exceeding a given throttle %. Ususally this is above 50%, hence fuel ecconomy in daily driving is not effected. The amount of throttle on cruising or light accelleration is very little, there is no effect on this, right through the rev range AFRs can be kept very lean if the loads are light, the factory ecu does a decent job of that. One of the 'problems' with the S-AFC is that at throttle percentages below the set one it applies a slight re-calibration to enable a smoother transition to the mapped area. It usually gives you curry around the torque peak as thats where timing map can't get too excited or you increase the risk of detonation.

The factory ECU has a set fuel map. If you whack an exhaust on or whatever you don't change it, rather the ecu doesn't 'adjust it'. You usually have better efficiency and require less fuel, meaning the map may be richer when measured. Throw increasingly more airflow through your motor and you will find the situation gets leaner and leaner because the map doesn't increase the injector times to suit, thats why we buy power FC's when we want to slap a high flow turbo on.

food for thought?

Fair enough.

If you drive around with your throttle below 50% then yes the fuel economy would be pretty nice. If I was to always keep below 50% throttle I'd get better economy but I like to enjoy my car's power every now and then - so for me the safc will hopefully just make the AFR's more efficient all round. I'm not trying to push it to the limit, just get a bit better AFR's at the top end and keep the ecu away from fuel cut, yet still well within safe limits.

I'm not sure what you mean about the car running leaner when airflow is increased. I mean - I understand the theory but I thought that with the stock ecu, as it detects more airflow it starts to dump more and more fuel in to avoid detonation...and the result is that it can end up running quite rich under boost, provided the fuel pump/injectors are up to it.

Either way, I've found that my car with the exhaust now appears to run much richer than without. The smell of petrol and black inside the exhaust is further confirmation of that. I'll be getting it tuned very soon so I guess that will sort out my worries.

Many people have used SAFCs before and had great results so I dont understand all the negative comments in this section of the forum when the skyline and stagea sections are full of people's great results with them.

Please dont take anything I say the wrong way, I'm not trying to argue - just trying to better my understanding and learn more about the way all this stuff works. I'm finding this discussion very helpful

[MKDR33]

Fair enough.

If you drive around with your throttle below 50% then yes the fuel economy would be pretty nice. If I was to always keep below 50% throttle I'd get better economy but I like to enjoy my car's power every now and then - so for me the safc will hopefully just make the AFR's more efficient all round. I'm not trying to push it to the limit, just get a bit better AFR's at the top end and keep the ecu away from fuel cut, yet still well within safe limits.

mate it depends on ur current mods, if u got a bigger turbo, FMIC, exhaust, injectors, fuel pump etc. SAFC wont effect ur fuel economy even under the 50% throttle range, u will NOT get more kms on a tank of fuel.. i know this from personal experience.. most ppl install an SAFC for power gains, and u cant get power gains and a decrease of fuel consumption at the same time..

Edited October 8, 2006 by MKDR33

[Rolls]

and u cant get power gains and a decrease of fuel consumption at the same time..

Yes you can, if its running rich eg 10:1 and you lean it out to 12.5 you'll make more power and have better economy.

[MKDR33]

Yes you can, if its running rich eg 10:1 and you lean it out to 12.5 you'll make more power and have better economy.

not true

just cause u tune the AFRs doesnt mean u get better fuel economy.. ur engine is working overtime, more revs, resulting in quicker injecting of smaller mixures of fuel..

im getting around 6km per litre atm, whereas i used to get around 12km per litre before the SAFC and my other mods including turbo upgrades..

[pixel8r]

Will see how it pans out after I get the safc installed and tuned.

I'm starting to think its just a matter of different results with different cars/setups.

Looks like everyone has different results with it. I know many people on the stagea section have reported good gains in power and economy with the safc and also the jaycar digital fuel adjuster (similar thing).

[Mike_]

I have been considering an SAFC II or an SAFC NEO on my car (fmic, intake, turbo back, adjustable cam gear) basically as a stepping stone, since I don't want to make much more than 200rwkw.

Anyone had any experience with the NEO and know the major differences?

Any idea if any of the traders on here sell them?

Edited October 8, 2006 by Mike_

[Links]

Bump...

Has anyone used the new SAFC NEO yet??.. with the PFC going EOL I might look at one of these considering my extreme lack of mods...

[mad082]

im getting around 6km per litre atm, whereas i used to get around 12km per litre before the SAFC and my other mods including turbo upgrades..

you just explained you poor fuel economy with the line about the bigger turbo. that adds more air, so the computer adds more fuel to keep the afr's right.

if everything is the same and you lean the afrs out from 10- to 12-1 you will get better fuel economy. at X amount of airflow you have taken the ratio from have 10 parts air/1 part fuel to 12 parts air/1 part fuel. now that doesn't mean that 2 parts air have been added, but 0.17 parts of fuel has been removed. now if that was done throughout the rev range (all ratios went from 10-1 to 12-1) that would mean you would get 17% better in fuel economy.

now what you said about the engine working overtime is only correct under the right circumstances. that is when you are accelerating up to as fast as you can in a given distance, then slowing down and doing it again (like racing). but then the leaner mixtures and the higher revs would probably work out to be about the same consumption as the richer mixtures and lower revs. in situations where you are just accelerating up to a set speed then the leaner mixtures will get you there quicker, using less fuel, and then you spend more time at lower throttle, so the fuel consumption is less. the richer mixtures still revs up to the same speed, but uses more fuel each times it is firing, and because it has less power and is accelerating slower, it will have to fire more times before it ca cruise.

Edited November 24, 2006 by mad082

[Gazee]

SAFC 2 neo watever the hell they've baught out now is a waste.... extra $400-500 + Tune you get full engine management not a ecu tricker...

And apparently i got 214.5kw when it was tuned at chasers but you cant trust dyno shootout mode sometimes....

.....just my 2 cents....

Edited November 24, 2006 by R33HVN

[mad082]

and for that axtra $400-500 + tune you won't get much more power. i know people that made the same power with a pfc as they did with a safc, but gained a touch more mid range.

for people with autos they are a good idea as most full ecu replacements cause crappy gear changes. if i had an auto i'd be looking at a greddy emanage ultimate as they can control timing, fuel, and can even have a map sensor added so you can keep mapping even when the afm maxes out. similar price to a pfc, but you retain all the drivability of a stock ecu (cold start, etc)