1g Maft + Dejon Blow through + 680cc

[Infinity03]

Anyone have any advice on the following.

Currently i have and want to install:

680cc injectors
Dejon Upper intercooler blow through setup
greddy type s bov
maft translator
3' gm maf

My issue is that i want to avoid getting into heavy tuning that may lead the car to be down for days at a time. I would like to install the above and set the translator to the injector size and get at least stock performance out of the car. i have heard in the past that i am forced to buy an AFC to lean out the injectors. is this true? Could i set everything up as described and have a decent idle / running car? An afc is somewhat intimidating only because i have a tendancy to over analyze and expect things to be perfect

Current setup

Stock engine
Stock intake and side mount intercooler
Pocket logger ruunning MMCD
Aem Wideband ( in the box)
SBR Evo 3 16g turbo, SBRmanifold, SBR 02 sensor
3" Turbo back exhaust

Running conditions

street driving / no racing / occasional boosting

sorry for the long post :/

thanks in advance

 

[SonySlave]

With the MAF-T, you shouldn't need the S-AFC. The MAF-T can compensate for the 680s on its own. When you install the translator, make sure you read the instructions and tune the dials in the box to compensate for the 680s. It will work fine.

 

[snowborder714]

I would not trust the MAF-T to allow you to tune for 680's. The MAF-T is known to be very sporadic in it's tuning capabilities. Also, 680cc is at the very limit (or beyond) of the S-AFC's capabilities. I would recommend looking into some other form of air/fuel control than an S-AFC if you plan on keeping the 680's. Also, since you don't have a logger, I really won't trust the MAF-T to tune for the 680's since you won't be able to see how the car is reacting. I'd recommending getting a logger ASAP if you want to install the 680's. MMCd is a free one that seems to be pretty popular around here.

Also, get an AFPR since you have a 255lph fuel pump. You're overrunning your stock FPR.

 

[Infinity03]

oops - forgot to mention


i have a aem wideband - not hooked up and a pocket logger running MMCD

so what if i were to buy 550's and get rid of the 680's? i only want a max of 375 hp

 

[snowborder714]

This was taken from a post steve made in another thread:

The formula for sizing injectors is based on target HP. Brake Specific Fuel Consumption for a turbo engine ranges from .60 to .68. Maximum Injector Duty Cycle should be between 80% to 85%. 10.5 is the coversion from lbs of fuel per hour to cc per min.

size (cc) = ((HP * BSFC)/(#injectors * MaxDutyCycle)) * 10.50

So, according to that math, you would have 753cc at base pressure. So if you're shooting for 375hp, then you'd need at least 750cc or 850cc injectors to get to that goal. And they won't be able to be controlled by an S-AFC. Also, as I stated earlier, don't forget to get an AFPR.