Understanding on fuel cut

[giterboosted]

Ok so I have a greddy profec b spec boost controller and an apexi afc neo, so I have all the adding fuel to the mix covered, how can I raise boost cut, I'm hittin it at about 14 psi on a 57 trim.

I'm not looking for astronomically high boost just a Lil more than I've got now, any ideas?

 

[jdub]

On a stock AFM, that's maxed out. (kinda surprised you're that high)

 

[giterboosted]

Dang I feel dumb, sorry it's a lex afm, shoulda said that before

 

[gaboonviper85]

you are maxing out the lex afm...good friend of mine is hitting fuel cut with his 57 upgraded ct at 15 psi so yours sounds about right. youll have to finally change to a standalone or maftpro type setup using speed density

 

[jdub]

Even with a Lex, you will max out at 16-18 psi of boost depending on OAT, the IC piping, type turbo, and DP used (plus a couple other factors). Keep in mind FC is determined by the volume of air that flows past the AFM, not the psi produced by the turbo. As a result, every car is going to be different - even those with the exact same turbo configuration.

 

[giterboosted]

Well I have a maft base model tho, never coul get it to work rite, maybe now that I have a better understanding of my engine (that was about a yer and a half ago) I'll have better luck, will my afc neo still work the same with a maft?

 

[kamikazemkiii]

With maft pro theirs no need for the neo. Sell it and get some $$

 

[giterboosted]

Base means not pro

 

[giterboosted]

Nobody? It's a base model low as you go maft, just a box with some wires to a gm maf, all I wana know is will my neo still be effective

 

[ohiosupramst]

You no longer need the neo hooked up at all. The maft pro is a piggyback just like the neo but it uses a speed density sensor which is better than a maf.

 

[ohiosupramst]

You might want look into shielding your knock sensors better than stock (40% shielded)when using maft pro just what I heard.

 

[jdub]

What do the knock sensors have to do with fuel cut?

 

[Kckazdude]

Nobody? It's a base model low as you go maft, just a box with some wires to a gm maf, all I wana know is will my neo still be effective

You will still need a way to tune with a MAF-T. All the MAF-T does is convert the signal from the larger GM MAF sensor into a signal the TCCS recognizes.

 

[giterboosted]

Thank you!!! I tried to tell ppl it's NOT maft pro it's just plain old maft, nothing special about it, ao yes it will be just fine to run the neo with the maft

 

[grimreaper]

keep the neo to fine tune the maft-t. And speed density is not better then a MAF. Whats the 40% insulation tid bit ?

 

[airhead04]

Dont let Ian see you saying I HEARD in the tech section. He will rip you a new ass. Im suprized jdub hasnt yet. lol

 

[jdub]

Im suprized jdub hasnt yet. lol

Patience weedhopper

 

[Kckazdude]

^^ Been waiting on a reply myself.

 

[TurboStreetCar]

The Base MAFT does allow some tuning, its just not very great. If you dont want speed density then go MAFT GEN2. It alows greater tunability without the need of a SAFC of any type.

If you want to raise fuel cut without going standalone run 50psi base fuel pressure and pull crazy amounts of fuel. This will raise fuel cut but also cause a more advanced timing curve. Gotta pay to play.

 

[bountykilla0118]

Ok so I have a greddy profec b spec boost controller and an apexi afc neo, so I have all the adding fuel to the mix covered, how can I raise boost cut, I'm hittin it at about 14 psi on a 57 trim.

I'm not looking for astronomically high boost just a Lil more than I've got now, any ideas?

First thing what is your setup and second do you have a wideband? Are you adding fuel with the NEO? If you are adding fuel what is your base fuel pressure when the car is warmed up to operating temps?

Once you know those little but important things you can start to play with your air/fuel ratio....

1) Adjust fuel pressure to so that the car idles well (dont worry about the a/f ratio #’s at idle to much)

2) Drive the car and watch the you a/f ratio while driving normal (normal driving should stay between 14 and 15 a/f)

3) Do a quick pull and watch your a/f ratio when flooring it (or wide open throttle WOT for short)

4) Once you have an idea of what your car is doing then make some changes. If you are running 550’s and the Lex AFM you should be around 10-10.5(a/f) with the stock tune, but that will change according to your specific setup. Typically bumping up the fuel pressure and scaling back using a piggy back with get up fuel cut up in the 20’s (in terms of psi).