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Has Anyone Evern Bothered To Try?


zazzn

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Why does it stop at 4k RPM? Has anyone ever answered this? After this it goes to preset maps that are based on the previous O^2 readings, correct? And its MAF-dependent before the 4k rpm cutoff? Is there anyway to make it so that the fuel-curves are MAF dependent?

You've got it a little wrong. It doesn't depend on the MAF till 4000 RPM.

It depends on the 02 Lamda sensor to reach a 14.7 optimal burn ratio for best fuel mileage. When you floor it and the ecu switches modes it relies on the MAF even before 4000 you'll notice this on any dyno by a rich dip in the a/f. All changes made to via the S-AFC modify the signal outputted by the maf. So if I wanted to add fuel I'd add signal making the car think I'm doing MORE load then i'm really doing. That’s why S-AFC suck jerk to add fuel, they are good for pulling fuel.

If you add signal all you do is hit the fuel cut off earlier. That’s why I said you need to clamp the MAF signal then add fuel manually with a Fuel pressure regulator or something. Bigger injectors suck too because they make the whole power band rich. (only suck if you are not maxing them out)

Dougs - I just RE answered your answer. we are not adjusting the static map, simply moving up or down it with s-afc.

Plain and simple there is no difference here then any other mass air metering system. No manufacture has an adjustable ecu, all EFI cars need to know the amount of air or load put on the engine to determine how much fuel to add.

The piggy backs just skew the numbers and you as the user have to make up the diffrence.

AGAIN FOR THE LAST TIME A S-AFC DOES NOT MODIFY THE ECU. IT MODIFIES THE SIGNAL GOING TO THE ECU EFFECTIVELY TRICKING THE ECU TO THINK IT'S EAITHER HAS MORE LOAD OR LESS LOAD THEN WHAT THE MAF IS READING.

Example

Imagine the following was how much map was left till I hit fuel cut.

|-----|>-----------|

Now I add 25% signal but still run the same boost and don’t change ANYTHING ELSE

|------------|>-----|

As you can see we are much closer to fuel cut here because I added signal, but because I’ve moved up the map I’m not much more rich as I’m only 10 psi but the ecu thinks I’m doing 13. Also my timing has decreased slightly.

Slater- Thats the best Idea I've heard yet.. Unfortuantly, I don't think it was ever come to light unless someone spends alot of time understanding the asselmby hex. After spending all that time they have to release it freely to the community. Problem is that people don't they sell it or work with someone like upsolute. But for now until we have the software there is no reason why we can't use piggyback.

:)

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sounds good and cheap.. we could compare differences with aftermarket offerings and the base stock volvo ecu to get an idea on what changes they make, etc etc, once we disassemble what's being relayed its only a matter of time until we find out what else is and isn't effective...

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To be honest I dont think I will do a S-AFC but a FPR and a zenner diode on the MAF. I don't know if a HKS FCD works on this style AFM... But it may.

Anyways, as I said 18 psi daily........

Unfortuantly I just droped 600 at FCP for headlights/turns and an OBD2 reader. I believe I need a 02 sensor and now my car just started missing like carzy after I powerwashed the engine bay... I found the source and fixed it last night (distrib cap) but it's missing again so I'm guessing it got all carboned up again, before it wouldn't even start.... bah...

never again!

Blew up one of my champion sparkplugs some how.. But anyways, should be nice in the summer with a 3" down pipe.

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Guest DougK

To be honest I dont think I will do a S-AFC but a FPR and a zenner diode on the MAF. I don't know if a HKS FCD works on this style AFM... But it may.

Anyways, as I said 18 psi daily........

Unfortuantly I just droped 600 at FCP for headlights/turns and an OBD2 reader. I believe I need a 02 sensor and now my car just started missing like carzy after I powerwashed the engine bay... I found the source and fixed it last night (distrib cap) but it's missing again so I'm guessing it got all carboned up again, before it wouldn't even start.... bah...

never again!

Blew up one of my champion sparkplugs some how.. But anyways, should be nice in the summer with a 3" down pipe.

Im running 16psi daily on mine. Not really a big deal there... I could probably run 18psi w/out trouble. I've got some good meters in route and some tricks up mysleve to see whats she's still got left.

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