Rich AFR Or not?

[JAP63]

Question....
With the following fitted.
(No boost increase..just standard)

-510's
-A Small 16 G fitted
-Unchipped stock dual board ECU
-A Standard AFM


Would you expect the car to be running richer than it would be if it was just standard...(14B,450's) etc...or the same?

Or would it go lean?

 

[Entaran]

Difference will be next to nothing. maybe 0.2 or 0.3 richer.

Add a fuel pump and that'll go out the window on the stock FPR tho.

 

[JAP63]

What about this summation

The 16g adds around +25% at peak flow.(compared to 14B)
The 550's add around +13% at full flow.(compared to 450's)

Does that equal a lean outcome.

 

[Entaran]

What about this summation

The 16g adds around +25% at peak flow.(compared to 14B)
The 550's add around +13% at full flow.(compared to 450's)

Does that equal a lean outcome.

Your ecu will automatically compensate based on increased airflow at the maf

 

[JAP63]

So the stock MAF has it sorted?

That mean i wouldnt need my SAFC2?

Reason i ask is bcos i have this exact setup....and my SAFC2 Is at figures up to +17(which is really +30 b'cos i have 510's)...i dont want to run lean....but it still gets knock numbers that are preety high at times (i know it could be phantom)..but i dont like chancing it..plugs dont look all that black either...so i can turn my SAFC2 back to 0 and start saving fuel?

I know evo zeros (510'5/16G small) had a different fuel factory map though.

 

[brisvr4]

Are you logging all of this to see what you need to have the safc set at Jamie?

 

[Entaran]

Your ECU will compensate a certain amount regardless. It's not -that- stupid.

Mitsub ecu's are infact quite smart as far as ECU's go. They -can- and -do- compensate for increased airflow quite well.

It will be running richer, but the knock you're seeing is most likely phantom. Let's see the logs and we can make a call.

If you want to know about resetting the SAFC... then run it, log it, reset the safc, run it, log it... compare.

 

[JAP63]

Thatd be great..i have a dual board though...not loggable..guess id just have to get it tuned.

 

[vertex_vr4]

Your ECU will happily compensate in Closed loop.
However, in open loop your at the mercy of the stock fuel maps.

I'm not sure if the L/M/H Trim compensation kicks in when in openloop. Can anyone clarify?

btw: I don't think running a 16G (or 20G) turbo makes any difference in either open or closed loop. It just means you run off the end of your fuel map much earlier (and probably go lean). Thats when you need to go Wolf3d or chip for running extended maps.

Again if someone can clarify that would be great....

Cheers,
John[/i]

 

[JAP63]

Your ECU will happily compensate in Closed loop.
However, in open loop your at the mercy of the stock fuel maps.

sweet..so forget about tuning the low side of the SAFC2 map then

L/M/H Trim

whats that?

 

[brisvr4]

Trims aren't going to be of much use to you Jamie as you can't log them anyway

 

[vertex_vr4]

L/M/H Trims are Low/Medium and High...

These are the long term trim values that are used (and updated) by the ECU to get a more accurate 'first guess' when injecting fuel.

The ECU designers knew their sensors were less than accurate and also would skew at different RPM/Flow (can't remember which one ATM)
So they had longterm storage for the fuel trims which adds a percentage of fuel to whatever the stoic calculation happens to end up at.

The product of the equation here (exhaust gas) is measured by the O2 sensor and the short term trim is updated instantaneously. If the short term trim holds lean or rich for more than a few seconds the ECU begins to update the long term trim for that particular range.

 

[JAP63]

Thats what im talking about..even though im kinda lost in that field..its good to know people on here know their shit...

I might just look at getting a basic afr tune with the SAFC2...

even thought at the moment it has to be running rich with the settings ive given it..

Its wasting fuel.

Bit off topic..but how many @ all4 Kw will the standard vr4 pump take?
150-160kw?