Orb

iTrader: (3)

Ok, so correct me if I'm wrong but...

After looking at the DIY FCD and then thinking about it a little, that just doesn't seem like a smart way to go.

To allow the normal fuel/air rates up until a certain point and then lie to the ECU and then have your
fuel remain at a steady rate while your airflow continues to climb just isn't good. As everyone already knows.

So, why not just lower the turbo sensor output by 20% and increase fuel pressure accordingly?


Do away with the built in FPR and get an adjustable one. Calculate the desired increase in PSI over
the normal fuel cut point and then increase fuel pressure the same to maintain the same air/fuel ratio.

It'd be a lot easier to lower the turbo pressure sensors output across the entire range and that way
it would remain linear allowing you to increase injector flow and maintain safe a/f ratio regardless of boost.
Up till you max out your injectors of course...
You could easily set the desired max boost before fuel cut with a precision pot.

I'm guessing you would have to increase fuel pressure by a greater percentage then you decreased the
sensors output to get the correct flow but there are injector flow calculators to quickly determine that.

Or am I missing something?

Regards,
Orb

walken

iTrader: (6)

increased fuel wont do it alone. you need timing retardation. best fcd - pocketlogger.com

solareon

iTrader: (1)

FCD = ghetto and asking to blow your motor
Rtek = win

www.pocketlogger.com

arghx

iTrader: (3)

From the factory the fuel delivery is determined mostly by the AFM signal, not the pressure sensor signal.

I wish the Rtek 2.1 had an adjustable fuel cut rather than eliminating it completely. In the event of crazy overboost I'd rather hit the fuel cut.

Orb

iTrader: (3)

Sounds like an o-scope would come in handy here.
Monitor the injector signal while playing with the turbo sensors output and afm signal output.

But if the turbo sensor only has a small effect on fuel then you would only need to slightly increase fuel pressure right?

Injector pulse width graph with a FCD installed would be nice.

But if fuel is mostly determined by afm signal then why such the danger in using a FCD?
And if that's true then the best way around fuel cut is with a
FCD that lowers the signal across the entire range...
Would only slightly lean out the mix across the entire rpm range...

AmviciousRav

iTrader: (5)

the safest is way to fcd a fc is to swap in a v8 cuz that's what your gonna end up doing if your playing with fcds haha

my solution for fcds are NO FCDS!!!!

get a stand alone if you want more boost and a reliable car