121 replies to this topic

[speedster]

Not related really but still interesting.... as you adjust the fuel levels lower with the SAFC-2 the ECU will start to detect the change (through its primary 02 sensor I believe - you can measure this change with a voltmeter) and will compensate by increasing the injectors fueling cycle

Ah, damn. I thought this wasn't a problem due to the way the SAFC fakes the MAP signal into the ECU...

By lower I should of specified lower than the standard A/F mix burn so you should still be able to adjust successfully for any over fueling.

[speedster]

Decided to get off my lazy ass today and install the LM-1 and wide-band. Am logging 4 additional inputs via the RPM add-on. Haven't made sense of all the data yet

Here is a snapshot of my first log.

Key
Purple: Lambda (O2)
Black: RPM
Red: Throttle position
Green: MAP sensor output (SAFC-2 input)
Blue: SAFC-2 output to ECU

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•  speedster_lm1.gif   120.18KB   0 downloads

Edited by speedster, 02 January 2006 - 08:01 PM.

[speedster]

Same shot showing the Lambda scale... The difference between the green and blue lines represents the correction the SAFC-2 is currently applying to the ECU's MAP feed.

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•  speedster_lm1_2.gif   157.77KB   0 downloads

Edited by speedster, 02 January 2006 - 09:28 PM.

[speedster]

AFR and RPM only

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•  speedster_lm1_afr.gif   100.39KB   0 downloads

[speedster]

...and the AFR chart

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•  speedster_lm1_chart.gif   9.48KB   0 downloads

[cicastol]

GREAT!!! This week finally, i will install the safc,but i've removed the rear clam waiting for the 68mm TB ,so until next month i can't test it!! You use 04 in & 04 out sensor number??

[speedster]

Here is the monitor window. It can run in real-time mode if you connect a laptop whilst driving or play back a downloaded or previously save LM-1 log file. cicastol I will double check my sensor setting tomorrow.

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•  speedster_lm1_gauge.gif   10.05KB   0 downloads

[paulf-cam]

AFR and RPM only

I take it that AFR spike to 22:1 was a glitch?!

[speedster]

I didn't have the O2 Sensor 100% plugged into its socket on the LM-1. Hence in this log you can see the bumps on the road

[WazzaVX220]

Sorry to be a Pillock but.................. What exactly does this piece of kit do? Is it a more sophisticated ECU? Does it work in conjunction with the Standard ECU? Benefit for Modified cars only? My NA is full stage II so just interested in any 'improvements' Cheers.

[speedster]

Sorry to be a Pillock but..................

What exactly does this piece of kit do?

Is it a more sophisticated ECU?

Does it work in conjunction with the Standard ECU?

Benefit for Modified cars only?

My NA is full stage II so just interested in any 'improvements'

Cheers.

Yes, it is a piggyback - it works in conjunction with the cars standard ECU.

Essentially the SAFC-2 allows you to manage what air pressure the ECU registers over 12 points along the RPM range, for both low and high level throttle positions - that means you have 24 control points in total.
For example if the air pressure at 5500 RPM on full throttle produces 4.5 volts from the MAP sensor the SAFC-2 could be programmed at this RPM + throttle position (high) to supply the ECU with 3.8 volts (you substract or add to the ECU MAP sensor reading by percentage points, up to 50%, either way to a min. of 0 volts and a max. of 5 volts). This means you get some control on the amount of fuel the ECU supplies via the injectors because air pressure is part of the algorithm utilised by the ECU in determining the Air Fuel mix required by the engine. In the above example the Air Fuel Ratio (AFR) would be leaner than the AFR the ECU normally supplies to the engine.

In summary with this modification you are forcing the MAP sensor output through a filter (the SAFC-2) which alters what the cars ECU sees at its MAP sensor input.

Usually such equipment is useful only on modified cars. If you have a full stage two and if your fuel map was created by a vendor with all the necessary equipment (rolling road, gas analyzers, etc.) and assuming they allocated your car the necessary time to get the job done right, then the SAFC-2 may not be any addition. I am using it because I have have no option but to do the AFR tuning myself (plus I enjoy it).

The LM-1 kit (software screenshots above) is used to monitor and record how the car is burning the air/fuel mix via a wideband O2 sensor. A wideband is a more accurate sensor than the standard item. In our case the wideband can be used to replace the O2 sensor after the CAT (replace the standard sensor with an O2 sim to prevent an EML) though a CAT will effect the sensor reading, making it a little leaner.
Monitoring and logging additional sensors inputs like throttle position (TPS), RPM etc. allows you to determine how well the car is making power and provides the necessary data for you to sit down and calculate improvements.

Used together one should be able to get a fueling map which works well with current and any future modifications.

The SAFC-2 is a rather primitive form of A/F management but it does get the job done and I am finding it a useful tool to learn the basics.

Hope this helps

Anybody, feel free to correct me if you think I got something wrong.

Edited by speedster, 03 January 2006 - 08:42 PM.

[WazzaVX220]

Thanks! More questions later! In basic terms, is this solely about efficiency, or are you essentially looking for more power. I realise these two are linked, but what is your goal? It all looks fascinating!

[speedster]

Goal is to safely and efficiency obtain the maximum power from the modifications I have and am applying to the car, to avoid dangerous lean conditions or wastefully rich conditions and learn some along the way.

Edited by speedster, 03 January 2006 - 09:21 PM.

[speedster]

GREAT!!!
This week finally, i will install the safc,but i've removed the rear clam waiting for the 68mm TB ,so until next month i can't test it!!
You use 04 in & 04 out sensor number??

Hi cicastol, I am using 5 in and 5 out for the sensor number. I managed to get my hands on an oscilloscope. When I get some leads, duh! I will trace both the actual MAP output and supplied SAFC-2 outputs, to determine if the SAFC-2 is supplying anything different in terms of waveform.

[cicastol]

Hi cicastol, I am using 5 in and 5 out for the sensor number. I managed to get my hands on an oscilloscope. When I get some leads, duh! I will trace both the actual MAP output and supplied SAFC-2 outputs, to determine if the SAFC-2 is supplying anything different in terms of waveform.

Now i'm in the SAFC club,installed today!!
All works great,i've tryed different sensor number from 1 to 7 ,if you check in monitor the value displayed(pressure) change with different sensor number(engine off, maximum pressure in the intake=air pressure) from 1 to 7 best is 5,tomorrow i will try all the sensor numbering to 20 watching for the more accurate reading of the pressure!!
Thanks very much for the reference wiring diagram that you made,hope hat someone put it in the DIY guide!!

[paulf-cam]

In our case the wideband can be used to replace the O2 sensor after the CAT (replace the standard sensor with an O2 sim to prevent an EML) though a CAT will effect the sensor reading, making it a little leaner.

Thats the wrong sensor to change isn't it? Don't you need to be reading the o2 levels *before* the cat to see what the engine AF ratio truely is?

Cheers, Paul.

[speedster]

In our case the wideband can be used to replace the O2 sensor after the CAT (replace the standard sensor with an O2 sim to prevent an EML) though a CAT will effect the sensor reading, making it a little leaner.

Thats the wrong sensor to change isn't it? Don't you need to be reading the o2 levels *before* the cat to see what the engine AF ratio truely is?

Cheers, Paul.

Yes, the correct sensor is the Pre CAT sensor but you cannot remove the standard sensor as the car's ECU utilises this for it's A/F reading. Using the post CAT sensor is workable but you need to understand that the AFR readings will be a little leaner that the actual values. Of course if you have removed the CAT none of this matters.

I am thinking of enquiring with Milltek if they could put a Cell 100 CAT on a down pipe for me with two O2 sensor ports prior to the CAT.

[paulf-cam]

I imagine tuners like courtenay and thoney have the same problem - all they can do is stick a wideband up your exhaust and compensate.... Ta, Paul.

[cicastol]

This is how i 've installed my new gadget:

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•  DSC_0058.jpg   81.07KB   0 downloads

[speedster]

looking good cicastol great to have a second head on the case