Fueling Question

[oversteer180]

Ok I Have an ca18det with 450cc injectors, t25g, and fmic. Im getting my ecu chipped for the injectors. Will I need an safc to tune the car, as well as my ecu being chipped to run properly, or will it be fine with just the ecu chip Im about to order?

Also, I am on stock fpr, and stock 240sx fuel pump. Will my car be alright, or should I go ahead and upgrade to an afpr and high flow pump? I plan on running the stock boost and didnt know if i upgraded the fuel pump the fpr would be overun. Or If i didnt upgrade the fuel pump\fpr the car would run too lean and kill itself with the larger injectors not having an high flow enough pump going to them.....

Thanks....

[c-rad]

It depends what exactly the chip is tuned for. If its just a base tune with a correction to the K value, then yes you would need a secondary tuning device to make peak power. If the fuel/timing maps were altered any, then you may be able to pass on a SAFC.

Do NOT, and I repeat, DO NOT use the stock 240SX pump. It doesn't pump out nearly enough fuel, even for a mostly stock CA nevermind one with upgraded injectors/turbo. Stock FPR should be fine though.

[float_6969]

You'll prob need a SAFC to fine tune the fuel maps after the ECU chip.

And DEFINATLY don't run the stock fuel pump. A guy I know just burnt up a piston on his SR doing that same thing. It didn't happen right away, but it happened.

[oversteer180]

Hmm, how hard is it to set up a tune with the safc? Should I even get an ecu tune if im going to be using the safc?

[89'ClubK's]

The SAFC II isn't hard to use, it's just hard to find the correct settings. Depends on the engine. As the others stated, use a Walbro pump in order to get enough fuel. If not, the car will run lean. Bye Bye engine

[c-rad]

Hmm, how hard is it to set up a tune with the safc? Should I even get an ecu tune if im going to be using the safc?

Yes, DEFINITELY get an ECU tune. The SAFC is good for minor adjustments. In case you don't know how it works, the SAFC just lies to the ecu about the amount of air coming in. Well, the ECU uses the amount of air (throttle position, rpm and O2 voltage) to determine a total theoretical pulsewidth which is what points to specific parts of the fuel and timing maps. The lower the amount of airflow, the more timing advance the ECU gives out. As you may guess, this can cause a problem with detonation if you lean out the safc too much.

A base rom for the ECU will directly change the injector size so you can make smaller adjustments with the SAFC.

[oversteer180]

alrighty thanks c-rad