pixel8r

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

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.

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.

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...

Its an auto so pfc is a no go. I'm not planning on boosting it high enough to get any fuel cuts etc. Just around 12-13psi should do fine I think. Turns out the safc i have is version1 not 2 so I'll be selling it and getting a new one. Bought the current one from a member of this forum and was told that safc2 came in a v1 or v2 with same functionality but one has buttons and the other has the round knob. It is the blue screen one - but from what i've read since it looks just like a safc1 and I think i was scammed. Should be able to sell it again and recover my money. So now i'm looking at something like a SAFC2 and AVCR. Will talk to the workshop I'm taking it to and see what they recommend first tho.

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?

350Z performance shouldn't be that bad. The specs say its like 206kw or something and 0-100 in 6 seconds. Its very light so a na engine still makes it go. Just no boost surge or easy upgrade potential you get with a turbo. I still wouldn't buy one, but I would be happy if I was given one

Yeah i've been thinking a bit more, now that I have the manual boost controller...I'd probably rather pay the extra for a full ebc. They're more tunable and hold boost reliably and they usually have the ability to have 2 presets that you can switch between from inside the car. I've now got the full 3" exhaust and it now runs 10psi. The turbo is a gt30 (ball bearing, all steel wheels) so no probs with boosting it up a bit. Still have to put the safc on it and get it tuned but I want to put the boost controller on it at the same time and tune the boost first and then the safc to match. Just for the record however, the manual boost controller mentioned is not a bleed valve and many people have mentioned above that they hold boost very well.

raz0r was correct, air is made up of ~80% nitrogen anyway. Then there's something like ~18% oxygen and a couple other gases. So whilst there is a difference, the difference between pure nitrogen and normal air probably isn't as much as it sounds.

My Stagea S2 (rb25det neo - same as r34) is 1658kg compared to ya skylines (1400kg or less) so I'd expect the fuel economy to be worse. Stock, the stagea did about 13.5L/100km city driving and 10.7L/100km on the highway. Fit an SAFC or equivalent unit and these numbers will drop (the rb's run fairly rich from the factory). Some guys have seen about 12.5L/100km in the city by installing a SAFC2 and exhaust. I now have 3" exhaust, apexi air filter, and GT30 turbo and 10psi boost. Lots better response and performance than stock, and so far economy appears similar but it runs very rich. I have an safc ready to be fitted and tuned so that should help the fuel economy a lot - and will even squeeze more performance out due to it running more efficient.

To get an inspection is easy. As long as you have the RWC from interstate and its currently registered then all you need to do is take it to the inspection station at regency (not the old rego & licensing building - i think the inspection place is on camira st or something) and they'll just check the VIN and a compliance plate etc. and thats about all. They also checked the rear windows on my stagea as they are dark (not tint, its called privacy glass) but other than that all was ok. I was only there for about 20 mins. You only need the full regency inspection if the car isn't registered or if its defected as far as i know. Nothing to worry about. Once the car is inspected its just a matter of handing the plates into a rego office and picking up your new ones and pay for your new rego. Easy as.

you dont need one with the aussie head unit. Check that the aerial is actually connected up to the head unit. You need to get an adaptor for the aerial plug - most car audio places have them (got one from tonkins a year ago). The FM expander is only for the jap radio.

I've got a GT30 turbo on my series 2 stag and have only recently got a 3" full turbo-back exhaust fitted and now the turbo hits full boost around 3000rpm or maybe even less. Really pulls nice and hard with almost no lag. Before I had the exhaust fitted the lag was very noticeable but now its only ever so slight. One reason is that the turbine now spins more free and another reason is that the engine breathes better and therefore builds revs quicker. I'm getting a safc2 fitted this week. Basically they just sit between your air flow meter and your ecu and modify the voltage that the ecu sees - enabling you to accurately tune your Air/Fuel ratios. Instead of running rich or lean, the SAFC can correct the AFR graph so that you're running much safer and more economical. You will also see improved performance as a result of your car being more efficient. Hope that helps. It does have limitations but provided your AFR's aren't too way out then you should have great results with it. Personally I'd get one of these before a fuel cut defender. Probably depends how much boost you're planning to run.

Wont be able to make it tonight. Plus I really should wait until my car has the safc2 fitted and tuned before pushing it too hard. Next time...

How well does the unichip handle the auto? ie. retard/cut ignition on gearshifts etc...

Actually from what i've heard you can get defected for anything standard as well - depends on the mood of the cop. If the car is legal you can head straight to a cop station and they'll remove the defect but it would still be unnecessary hassle.

But what about with only 0.5bar or 1bar - like he mentioned?? I know the stock turbo wont cope with 1bar for long, but what about the engine?? Have heard of plenty of people with similar mods to stagon running 10-12psi without problems. Sorry my knowledge is a bit limited on all this. Is detonation only caused by the mixtures running lean? ie. too much air for the amount of fuel? thats the way I understood it. Still it is definitely a good idea to try this on a dyno first and get an safc or similar to tune it properly.

OK, time for the verdict... Got the full 3" system installed today, all mandrel-bent (for what its worth) and I'm very impressed. I'll admit it is quite droney around 2000rpm but either side of that it sounds great. Sounds very tough too! Should reduce some of the 'volvo' comments For those interested, boost did go from 8psi before the exhaust to 10psi after. The low end response is GREAT. Still has a touch of lag but that has almost gone. What I mean is its not as brilliantly responsive as the stock turbo but once it STARTS to work it really starts to take off. Before it used to fall off boost abit when changing from 1st to 2nd but now it holds boost much better. I think the top end now runs fairly rich as the power seems to fade when the revs get high. I've got a SAFC2 on order (2nd hand) and when I receive that next week I'll be booking the car into boostworx asap to get it properly tuned. Should also have my boost controller by then so they'll be able to give me a really good compromise between boost and a safe tune (ie. AFR's). Hoping for between 140-160awkw. 160 would be great, but if it falls a bit short I'm not going to be too unhappy. The transformation is good. Noticeable less lag and greater response.

Wouldn't the stock ecu start cutting fuel or switch to R&R to stop the engine running lean? I figured you'd get these warning signs before the engine has any risk of blowing up...yes?

Pretty sure they do come off. Also a band expander will allow your jap radio to pick up our FM frequencies. But if you're replacing the headunit anyway then you'll be fine. You may however need a converter to connect the aerial to fit the new head unit (if you're installing it yourself). Most car audio places stock these. I needed one of these to fit a new head unit to a nissan silvia - so I'm just assuming that all jap cars have the different aerial plug (2 small prongs instead of the one bigger one we have here in aus).

Thats what I figured was the standard stock power for a s1. Mine is S2 so *should* have around 120awkw or thereabouts but instead only has 100awkw. Definitely a RB25neo and definitely no performance mods other than the gt30. I think its just the gt30 turbo not able to work efficiently. Still sits at 8psi but I dont know if that has any relevance. Anyhow it doesn't matter - the full 3" exhaust and manual boost controller goes on in 2 days so will look at how it goes then. Safc2 should follow soon after. Then the tune. Then I'm done. The transformation should be niiiiiice.

Cool. Actually a few things have changed with our situation and it looks like we'll be spending a little more for a custom exhaust. Same place I got the exhaust for the silvia. Full Stainless 3" with high flow cat and magnaflow muffler (and centre muffler to reduce noise and drone). I've heard great reviews about AAA exhausts shop and was quite happy with the sound and performance of the exhaust in the silvia. With that car it made 18rwkw improvement over stock with no other mods and the sound was fairly quiet for a 3" and had a nice note. So they should be able to work some magic with the stagea too. Will cost a bit extra but the performance and sound of the exhaust is so critical that I thought I'd just take the plunge and get a full custom exhaust. I stand by the work of AAA exhausts and if you search in the SA section of the forum you'll find many others swear by them too. So that will be going on soon. Hopefully fuel economy isn't upset too much (at the moment i'm off boost during city driving but if lag is decreased that may change - but other than that highway driving economy etc. should improve). Will also be looking at a safc (2nd if possible - cant really go wrong) and that should complete my setup for now. Hoping for between 140-160awkw and will find out when the safc is tuned. Normally an exhaust should give around 20kw increase atw for imports but with the gt30 turbo i'm thinking this could really take off. Note that I also am getting a manual boost controller in the mail soon and that will allow me to fine tune things a bit for now. Will post the results when its done for those interested...

Thats a very nice and detailed description - I like it! I'm now in the market for a good exhaust, and one question I have is about lag. Did the 3" exhaust INCREASE turbo lag? This is a problem I had when I put a 3" full SS exhaust on a s13 silvia (no other mods except high flow panel filter) - boost increased to 10.5psi and lag increased a little, although top end power was a lot better - 18kw better. Is it worth the extra money for stainless? I guess another way to ask that question is - is there any benefit to stainless steel over mild steel other than it doesn't rust and lasts longer?

yeah but what I was thinking is that the guage is measuring air pressure isn't it? So if the turbo is struggling to push air through because of the amount of backpressure, I'm guessing the boost pressure is the same but actual airflow is less. Would this be correct? or is boost pressure an accurate measure of airflow regardless of any restrictions?? Other cars on the same dyno on same day were getting quite good figures (none of them AWD tho). Pretty sure they used 3rd gear. Not too worried about the dyno readout. The car isn't a finished product yet anyway. If I'd done all my target mods and gotten a low figure then i'd be more concerned but at the moment its not an ideal setup so its hard to predict what the outcome should be.

Thanks heaps guys!! This advice is really what I need right now. Its not that I dont enjoy driving my car (hell, its still a stagea!!) - but I went with the bigger turbo #1 because ATS recommended it (not for my setup but for long term better option) and #2 it gives the car so much more potential and value than simply putting back the piece that broke. If I can pick up a cheap exhaust and cat I reckon that will improve things no end. What I'm getting now feels like sometimes its all free and the boost and revs build up fairly quick and the car feels very alive - yet other times it feels like the whole system is clogged up and i'm trying to stuff compressed air through a straw (literally i guess). I think this is all down to the exhaust. I now have an apexi panel air filter (dry - not a major mod but got it for $50 bargain), and a manual boost controller so with this I now have no problems upgrading the exhaust. 3" all the way is what I really want to do, since my current setup is welded all the way so if I have to get it all done I might as well replace it all. Guess I can sell the stocker too Tangles, thanks for the advice you've given. You're always giving me great ways to save money and still get the results I'm looking for - and thats fantastic. Sure it might be the cheap option but I figure its still going to be an upgrade and great value. Just out of interest - does anyone know if my turbo would be the reason why my s2 only has 100awkw? Wondering if even though the boost guage shows 8psi pretty solid, if its actually flowing LESS air and therefore getting less from the engine...(too much backpressure so the turbo is working too hard to produce so little).