Perfect for you. http://www.dsmtuners.com/forums/tuning-engine-management/278603-evo-maf-safc-680s.html

Hmm..what is said in that link doesn't really make sense to me. Let's say when you put a 2g maf and 550's to a 1g car, in order to compensate for the injectors you should click the SAFC to around -15ish, but the maf will lean things out from there. I've heard you should ad 10-15 for a 2g maf, bringing it close to zero on the afc and close to stock settings. So how would this be any different with an evo maf into a 2g car? anyone care to explain?

It said that switching the MAF does the same thing a tuning with an SAFC. They both fool the ECU into thinking there is less air flow, BUT with less flow, the car also adds more timing.

The only way around this is to get your car chipped, either DSMLink, Ostrich, or some other tuner. Even a base 680cc chip is all you need, then you can tune with SAFC from there.

knochgoon24 said:

It said that switching the MAF does the same thing a tuning with an SAFC. They both fool the ECU into thinking there is less air flow, BUT with less flow, the car also adds more timing.

The only way around this is to get your car chipped, either DSMLink, Ostrich, or some other tuner. Even a base 680cc chip is all you need, then you can tune with SAFC from there.

Click to expand...

But the MAF would be leaning it out instead of richening like the injectors would. They have the opposite effect on the car.

http://www.dsmchips.com/ This is what you should add to your setup for a great tune.

whiteflash said:

But the MAF would be leaning it out instead of richening like the injectors would. They have the opposite effect on the car.

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But you're ignoring the additional timing that comes with the ECU seeing less air flow. That's the problem with tuning by modifying the airflow signal.

knochgoon24 said:

But you're ignoring the additional timing that comes with the ECU seeing less air flow. That's the problem with tuning by modifying the airflow signal.

Click to expand...

If that is your concern with using 680's for your application, why not step down to something slightly lower? Your profile states that you have 450's still, so why jump that much further skipping 550's or the Lancer Evolution's injectors? Is it really necessary for your setup?

People install huge injectors all the time without even getting situated anywhere NEAR max IDC's with a moderate-sized set...

Just run a Keydiver chip. It does all of these corrections and more for you. You'll have perfect tune and will only have to use the SAFC for minute adjustments of +/- 1%

bboyalan said:

If that is your concern with using 680's for your application, why not step down to something slightly lower? Your profile states that you have 450's still, so why jump that much further skipping 550's or the Lancer Evolution's injectors? Is it really necessary for your setup?

People install huge injectors all the time without even getting situated anywhere NEAR max IDC's with a moderate-sized set...

Click to expand...

Greddy TDO5 18g, Apex'i TBE, Evo 9 fuel pump, DNP mani, 1g BOV, MBC, Precision 680's, FMIC

I used the EVO560's on my old GST and they were great, but I got the 680's for 100 shipped which is a pretty good deal.

Lonewolf64 said:

Just run a Keydiver chip. It does all of these corrections and more for you. You'll have perfect tune and will only have to use the SAFC for minute adjustments of +/- 1%

Click to expand...

I do plan on getting a Keydiver chip, but it might not be right away. And, I have an EVO maf in my room. I was just seeing if I could keep the timing from getting out of control before I get the chip. Anyway, all the parts listed in my profile are sitting in my room waiting to go on after school is over and I go home...So i've got some time

Here's a map from http://www.dsmtuners.com/forums/articles-tuning-ecu/258831-2g-eprom-tuning.html that I'll use for an example.


RPM are across the top and Boost/Vac | g/rev are down the side.

For a start, say you're at 3500 RPM and 17psi (2.2 g/rev). With stock MAF and no adjustments with the SAFC, you'll see 5* of timing.

Say you install the Evo MAF, which you say flows about 25% more air. So now your ECU "sees" 25% less air. The ECU now thinks your flowing about 1.7 g/rev. It you'll now have 9* of advance (average the 1.6g/rev and 1.8 g/rev at 3500RPM). That's fixed half of your extra fuel problems from the 680's (51% bigger than stock.)

Now you pull the other 25% with the SAFC. Your ECU now sees 1.1g/rev and now you have 20* of advance at 3500 RPM.

Now, if you just pulled 50% of the air flow using the SAFC instead of the SAFC/Evo MAF combo, your ECU would still see 1.1g/rev and you'd still have 20* of advance at 3500 RPM.

This is the problem with tuning for injectors by just adjusting the airflow that the ECU sees. You can control the fuel, but you can't control the timing advance. While you may now be running the correct AFR, you'll now be knocking from too much timing advance. This is why you're better off getting your ECU chipped THEN use the SAFC to fine tune.

whiteflash said:

Greddy TDO5 18g, Apex'i TBE, Evo 9 fuel pump, DNP mani, 1g BOV, MBC, Precision 680's, FMIC

I used the EVO560's on my old GST and they were great, but I got the 680's for 100 shipped which is a pretty good deal.

Click to expand...

Oh shit. My apologies; I must have been looking at someone else's profile .

Back on topic, have you considered using timing control? I know that some people have successfully used the A'PEXi S-ITC and S-AFC combination... or would a chip work better for you? I know that for the 3/S-platform, people use an ARC-2 MAF to replace OEM and set the baseline adjustments for the injectors there. They then do fine-tuning with an S-AFC.

knochgoon24 said:

Here's a map from http://www.dsmtuners.com/forums/articles-tuning-ecu/258831-2g-eprom-tuning.html that I'll use for an example.

RPM are across the top and Boost/Vac | g/rev are down the side.

For a start, say you're at 3500 RPM and 17psi (2.2 g/rev). With stock MAF and no adjustments with the SAFC, you'll see 5* of timing.

Say you install the Evo MAF, which you say flows about 25% more air. So now your ECU "sees" 25% less air. The ECU now thinks your flowing about 1.7 g/rev. It you'll now have 9* of advance (average the 1.6g/rev and 1.8 g/rev at 3500RPM). That's fixed half of your extra fuel problems from the 680's (51% bigger than stock.)

Now you pull the other 25% with the SAFC. Your ECU now sees 1.1g/rev and now you have 20* of advance at 3500 RPM.

Now, if you just pulled 50% of the air flow using the SAFC instead of the SAFC/Evo MAF combo, your ECU would still see 1.1g/rev and you'd still have 20* of advance at 3500 RPM.

This is the problem with tuning for injectors by just adjusting the airflow that the ECU sees. You can control the fuel, but you can't control the timing advance. While you may now be running the correct AFR, you'll now be knocking from too much timing advance. This is why you're better off getting your ECU chipped THEN use the SAFC to fine tune.

Click to expand...

Exactly what I was going to say except 680s are aproximately 35% larger than 450's. [1 - (stock injector size / new injector size)] * 100 = % more flow

OP- remember, PTE injectors are tested and measured @ 50psi Base pressure. They are technically the same injector that FIC sells as 650cc measured and tested @43.5psi base pressure. That means they should be compensated for as 650's if used at 43.5psi base pressure, and as 680's if they are being used at the pressure they were tested and measured at.

->PrOjEcTGS<- said:

Exactly what I was going to say except 680s are aproximately 35% larger than 450's.

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Drat... never mind. Still, the concept applies.

EDIT: Wait... I don't see how that forumla could be right. Then "900cc" injectors would flow 50% more than 450cc if that formula is correct, not 100% more (twice as much).

EDIT 2: I think I found the confusion. You're calculating how much air you'd have to pull. I'm calculating how much more the injectors flow. If you pull 50% of the air, you could run an injector twice a big, "900cc". With 680cc injectors, you'd only pull 35% of the air flow.

Stock injector requires X time to inject enough fuel for the air entering. The "900cc" injectors require half the time (X/2) to inject the same amount of fuel, so you'd just tell the ECU that it's seeing half the air, and you get half the duty cycle on the injectors (X/2).

So, OP, you'd need to be pulling approximately 35% of the air. Ok, that makes sense now. I just never went through the math.

knochgoon24 said:

Drat... never mind. Still, the concept applies.

EDIT: Wait... I don't see how that forumla could be right. Then "900cc" injectors would flow 50% more than 450cc if that formula is correct, not 100% more (twice as much).

EDIT 2: I think I found the confusion. You're calculating how much air you'd have to pull. I'm calculating how much more the injectors flow. If you pull 50% of the air, you could run an injector twice a big, "900cc". With 680cc injectors, you'd only pull 35% of the air flow.

Stock injector requires X time to inject enough fuel for the air entering. The "900cc" injectors require half the time (X/2) to inject the same amount of fuel, so you'd just tell the ECU that it's seeing half the air, and you get half the duty cycle on the injectors (X/2).

So, OP, you'd need to be pulling approximately 35% of the air. Ok, that makes sense now. I just never went through the math.

Click to expand...

Exactly...