evo maf, safc, 680's.

[turboking15]

i know that people say not to go much past 600cc fuel injectors if you are running an afc because it will pull to much timing. my question is what if i upgraded to an evo 8/9 maf that flows 25% more than my 2g maf. would that then allow me to run like a 680cc injector and still be able to handle them with an afc? seems like i could because 450 x .25 = 112.5, 112.5 + 450 = 562.5. so with just the evo maf i should be able to run 560 injectors with little tunning making a set of 680's manageable. can somebody tell me if i am on the right track or is there something i am missing. thanks for your help.

 

[SBR Joe]

I made over 400 hp in my 1g with an EVO maf, 780's and an afc..and drove the car every day getting almost 20mpg. You will be fine.



Joe

 

[turboking15]

what kind of timing were you pulling?
how hard was it to tune? and what turbo were you running?

any body else i want somewhat of a consensus before i purchase these parts.

 

[SBR Joe]

23 degrees at the top of fourth. I was running an SBR TD05H bastard 20g with 24 lbs on pump gas....11.7 afr's, and under 7 counts of knock. The car was really easy to tune, i wasnt AS concerned about knock because the afr's were good and it was pulling like a raped ape, but when i did log it it was under 7-9 counts most of the time, so it was all gravy.


Joe

 

[turboking15]

i will be running an e316g but want to go to a 50 trim eventually. will 680's be enough for a 50 trim with the evo maf and safc? also what was your fp?

 

[SBR Joe]

I was running a stock fpr with a supra 290lph pump and the 780's, so who knows what my fp was... 680s will be plenty enough with a 50 trim and your setup.



Joe

 

[steve]

my question is what if i upgraded to an evo 8/9 maf that flows 25% more than my 2g maf. would that then allow me to run like a 680cc injector and still be able to handle them with an afc? seems like i could because 450 x .25 = 112.5, 112.5 + 450 = 562.5. so with just the evo maf i should be able to run 560 injectors with little tunning making a set of 680's manageable.

Please think about what's going on and why people say that 680's are the limit.
What does the SAFC do to cause the ECU to correct the fuel and what's the side effect of that?

Now what does changing MAFs do? How does that effect what the ECU does?

Is this any different than using more correction (if it was available) on the SAFC?

The only way around this issue is to change the code inside the ECU to correct the parameters for the hardware involved. That's what a chip or DSMLink does.

 

[turboking15]

ok, that makes sense. then what would be the highest size injector one can go with an afc?

ive searched for this but ive seen everything from 550 to 750 so i would like a definative answer.

i know dsmlink is the way to go but that is out of my budget right now.

 

[steve]

ok, that makes sense. then what would be the highest size injector one can go with an afc?

It varies as Joe points out, some cars can handle the additional timing.

On one hand you have a hard limit by the correction range provided by the SAFC (varies by model) and on the other hand your limited by how well the car responds to the timing advance brought on by the shift in load mapping from the reduction in measured air mass.

My point was just to get you to understand that removing air via the MAF and via the SAFC isn't any different. The ECU doesn't know that is reduced or by whom so the result is additive.