Jump to content
SAU Community

Recommended Posts

Ok can someone clear this up for me... I have an r33 gts-t with a few bolton's as such she runs pretty rich.

Solution: went and got an SAFC II, had it fitted and tuned... all good power band feels a lot nicer and fuel economy goes up a little...

Problem: Battery goes dead and the car feels nothing like it used to... Confirmed that the settings in the SAFC have held so it's not like it has reset it's self

Ok so my questions is this... when you disconnect your battery and replug it in after draining any residual power out of the car the ecu resets it's self back to bog stock settings as such when you crank the car over it runs a little off eg idle hunts a bit etc then after a minute or two it feels normal again... I have always been told that these ECU's are a self learning ecu but that they don’t actually store any settings... eg on long trips it will adjust it for better fuel economy and if you strap it the car will get used to be revving harder and using more fuel etc...

I had my safc stolen a while back so it has been running on the standard ecu. I am just worried that when I hook the new one up and get it tuned it will be fine again till the battery dies... should I disconnect the battery first then get them to tune my SAFC... or alternatively should I just wack it on get it tuned... then disconnect the battery, reconnect it and whack it back on the dyno to confirm if my suspicions are correct.

Any comments including rage are welcome :)

Link to comment
https://www.sau.com.au/forums/topic/132582-safc-tuning-dead-batteries/
Share on other sites

the safc settings are stored in nvram so it wont loose them when its lost power. the ecu will perform a quick self init / self learn to maintain stable idle but its far from "retune feature"

replaced my dead battery, was going all the time.

hasnt affected the tune of the safc/sitc combo.

for a short while it seems off, but the 'feel' of the power delivery comes back. :laugh:

Don't forget that if your battery goes flat and the ecu does get reset, when it relearns - it'll be learning according to what the SAFC is feeding it e.g. modified values, not sure how this will affect it, but could be good just to get the tune checked..

Don't forget that if your battery goes flat and the ecu does get reset, when it relearns - it'll be learning according to what the SAFC is feeding it e.g. modified values, not sure how this will affect it, but could be good just to get the tune checked..

Yeah, might be an idea to reset the ECU with the SAFC disconnected and see how it goes.

See that's my thoughts. When it's tuned the first time it has done based on whatever the stock ecu has got in it's mind as default settings. The SAFC then just tricks the ecu into thinking what it wants... So if the battery is flat/disconnected then reconnected it's not going to know what it's original values were it will be taking what the SAFC was tuned with... i dont know maybe this is only making sence in my head as i can't find the correct words to type out :)

Don't forget that if your battery goes flat and the ecu does get reset, when it relearns - it'll be learning according to what the SAFC is feeding it e.g. modified values, not sure how this will affect it, but could be good just to get the tune checked..

the standard ecu has stock values but has the ability to learn if you've changed airflow etc no matter what you had before. the values change but not by much, it'll still put out the same values of airflow, timing etc after a battery change.

the safc stores all tuned data in its memory.

my car had no power into it for 6 months (rebuild) and when i put it back together it was exactly how i left it.

its nothing to worry about.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Could be. Could also be that they sit around broken more. To be fair, you almost never see one driving around. I see more R chassis GTRs than the Renault ones.
    • Yeah. Nah. This is why I said My bold for my double emphasis. We're not talking about cars tuned to the edge of det here. We're talking about normal cars. Flame propagation speed and the amount of energy required to ignite the fuel are not significant factors when running at 1500-4000 rpm, and medium to light loads, like nearly every car on the road (except twin cab utes which are driven at 6k and 100% load all the time). There is no shortage of ignition energy available in any petrol engine. If there was, we'd all be in deep shit. The calorific value, on a volume basis, is significantly different, between 98 and 91, and that turns up immediately in consumption numbers. You can see the signal easily if you control for the other variables well enough, and/or collect enough stats. As to not seeing any benefit - we had a couple of EF and EL Falcons in the company fleet back in the late 90s and early 2000s. The EEC IV ECU in those things was particularly good at adding in timing as soon as knock headroom improved, which typically came from putting in some 95 or 98. The responsiveness and power improved noticeably, and the fuel consumption dropped considerably, just from going to 95. Less delta from there to 98 - almost not noticeable, compared to the big differences seen between 91 and 95. Way back in the day, when supermarkets first started selling fuel from their own stations, I did thousands of km in FNQ in a small Toyota. I can't remember if it was a Starlet or an early Yaris. Anyway - the supermarket servos were bringing in cheap fuel from Indonesia, and the other servos were still using locally refined gear. The fuel consumption was typically at least 5%, often as much as 8% worse on the Indo shit, presumably because they had a lot more oxygenated component in the brew, and were probably barely meeting the octane spec. Around the same time or maybe a bit later (like 25 years ago), I could tell the difference between Shell 98 and BP 98, and typically preferred to only use Shell then because the Skyline ran so much better on it. Years later I found the realtionship between them had swapped, as a consequence of yet more refinery closures. So I've only used BP 98 since. Although, I must say that I could not fault the odd tank of United 98 that I've run. It's probably the same stuff. It is also very important to remember that these findings are often dependent on region. With most of the refineries in Oz now dead, there's less variability in local stuff, and he majority of our fuels are not even refined here any more anyway. It probably depends more on which SE Asian refinery is currently cheapest to operate.
    • You don't have an R34 service manual for the body do you? Have found plenty for the engine and drivetrain but nothing else
    • If they can dyno them, get them dyno'd, make sure they're not leaking, and if they look okay on the dyno and are performing relatively well, put them in the car.   If they're leaking oil etc, and you feel so inclined, open them up yourself and see what you can do to fix it. The main thing you're trying to do is replace the parts that perish, like seals. You're not attempting to change the valving. You might even be able to find somewhere that has the Tein parts/rebuild kit if you dig hard.
    • Can you also make sure the invoices on the box (And none exist in the boxes) are below our import duty limits... I jest, there's nothing I need to actually purchase and order in. (Unless you can find me a rear diff carrier, brand new, for stupidly cheap, that is for a Toyota Landcruiser, HZJ105R GXL, 2000 year model...)  
×
×
  • Create New...