MAFT topic beat into ground but im still confused???

[jaydm16]

I have decided to go with a 3 in gm maf, mass air flow translator ( not pro , and 550cc injectors. I have a general understanding but im wondering why some people still fuel cut their ass off.

It seems that i have to trick my ecu to see less air flow then use an additional fuel controller to supply the fuel. Shouldnt i be able to tune fuel with an afc or similar device. I thought i could boost high with injectors, maf translator, and gm MAF. Can someone clarify this? I have searched be i seem to get different results from different members.

 

[z1turbo]

Your fuel controler is what tricks the computer into seeing less air flow. The reason you can turn the boost up with an injector and translator or afc combo is because when you put the bigger injector in the car you have to dial back fuel from you tuning device and that tells the car that there is less air going into it. So you just lie to your ecu into thinkin there is less air in it so it doesnt fuel cut untill higher boost levels. The maft transltor is basicly an afc but it it allows you to get rid of the stock restrictive air meter and replace it with a better flowing one.

 

[GrimJack]

It's pretty simple... lets break it down into simple steps.

1. We put larger injectors on the car.
- The ECU thinks they are still stock size, so more fuel gets into the engine.
- Fuel cut still happens in the same place.

2. We put a larger air measuring device on the car.
- The ECU thinks the car is getting less air, so it sends a smaller signal to the bigger injectors. Now the car isn't running as rich.
- Also, the ECU thinks the car is getting less air, and as airflow is the single biggest contributor to Fuel Cut, this moves where we get Fuel Cut to a higher airflow setting.

By this logic, we can scale the signal from the air measuring device - if we make it smaller, the car will run leaner, and Fuel Cut will be moved up to a higher horsepower setting. On the other hand, if we make the signal bigger, the car will run richer, and Fuel cut will move down the horsepower band.

Does that help?

PS: The people that are still having issues with the MAFT and FC are in two categories - those with tuning problems, and those who are running big enough power that even with bigger injectors FC is still a problem.

 

[tomjan87]

If noone minds im going to join this with a question of my own in a similar area.

I am looking to go to the maft or lex/550
right now i have the lex aff, but nothing else for the swap. I did some research, and found that the maft would be cheaper, simply because i wouldnd have to upgrade to 550's right away.

I am kind of weary of tuning though, is it really hard to tune the car properly without the safc so it runs well, and no fuel cut. I dont think i would be running more than 12-14 psi, but still weary.

also, is the power made by both similar or does one make more power easier.

Thanks much
Joe

 

[GrimJack]

Tuning it is rather easy, but you need access to a dyno or a wideband, or something similar.

Power made is very similar... so much so that I'd say they are the same.

 

[forcefedsupra]

I have the maf-t, it is great. I do hit fuel cut easily because it is untuned. Another piece of advise, if you get this, fix all your boost leaks!