PFC monitoring RB25DET

[Dale FZ1]

I've been monitoring the sensor outputs on my PFC hand controller after fitting to my s.1 R33 GTSt, and just trying to assess where it's all at before spending time/effort tuning.

A couple of areas of uncertainty exist, even after doing the forum search:

Injector duty cycle max value @ 98.9%

AFM max output @ 5115 mV

Knock level max @ 29

Mods are 3" full exhaust + split dump, std airbox, FMIC, std turbo + boost, std fuel pump, exhaust pyrometer.

PFC is running unaltered maps at present, rev limiter set @ 6900rpm

The car is running much more cleanly/responsive than with the std Nissan ECU, so it's been a good thing from the start. Cruise and full throttle exhaust temps are about +30-40 deg C (max @ 740, cruise @ 630), so it's evidently running slightly leaner to generate the extra heat. I haven't yet run a fuel consumption check.

There is no audible knock, and forum search indicates this is well within safe limits.

At full throttle, high rev/load the Check engine light does flash then go off immediately with a lift-off. My concerns are about the AFM + injectors seeming to be at the end of their capabilities even though running standard boost (@ higher airflows than standard). Is this the end of the road for those components before I lean on the engine further through tuning the PFC and/or aiming for a tad more boost @ 10psi?

Is this the common experience when running these fairly typical RB25 mods?

cheers

[Sydneykid]

I've been monitoring the sensor outputs on my PFC hand controller after fitting to my s.1  R33 GTSt, and just trying to assess where it's all at before spending time/effort tuning.

A couple of areas of uncertainty exist, even after doing the forum search:

Injector duty cycle max value @ 98.9%

AFM max output @ 5115 mV

Knock level max @ 29

Mods are 3" full exhaust + split dump, std airbox, FMIC, std turbo + boost, std fuel pump, exhaust pyrometer.

PFC is running unaltered maps at present, rev limiter set @ 6900rpm

The car is running much more cleanly/responsive than with the std Nissan ECU, so it's been a good thing from the start.  Cruise and full throttle exhaust temps are about +30-40 deg C (max @ 740, cruise @ 630), so it's evidently running slightly leaner to generate the extra heat.  I haven't yet run a fuel consumption check.

There is no audible knock, and forum search indicates this is well within safe limits.

At full throttle, high rev/load the Check engine light does flash then go off immediately with a lift-off.  My concerns are about the AFM + injectors seeming to be at the end of their capabilities even though running standard boost (@ higher airflows than standard).  Is this the end of the road for those components before I lean on the engine further through tuning the PFC and/or aiming for a tad more boost @ 10psi?

Is this the common experience when running these fairly typical RB25 mods?

cheers

Without a power figure and/or A/F ratios it is a bit hard to comment on the injector sizing question. If it is rich and making less than 370bhp (220rwkw) then tuning will both increase the power and decrease the injector duty cycle.

It depends on where in the rpm range the AFM is reaching its 5.1 volts. If it is 5,000 rpm then it needs to be upgraded, if it is 6,500 rpm you can hold off.

[Dale FZ1]

No, it's at the top end of the scale - say 6200 - 6400 plus.

Initially I thought the check engine light was for knock warning, until I checked the max values and did a forum search. Then I inspected the airflow and injector duty, realising they were at the top of their scales.

Got to say I'm a little surprised at their limitations, but it makes sense to now do a dyno run even if only to establish a base to work from. Surely though, leaning off the fuel map won't pull duty cycle back that much?

I would presume that a "safe" max duty cycle to aim for would be in the 85-90% range.

[TTT]

I keep hearing 80% duty cycle as a safety rule of thumb.

[The Mafia]

ok, I can help here because I went throught the exact same scenario.

The injector duty cycle should drop to about 80% after you get it tuned.

The engine light, is infact the AFM maxing out at 6000 - 6500 rpm onwards. This is ok, I've been running it like this for about 8 months. Engine light flashes all the time on high revs showing the afm.

My knock never goes above 20 on the graph in all gears.

And remember, juast because you can't hear it knocking, doesn't mean it isn't. When you aren't playing with settings, always leave your HC on the knock graph. and remember if you give the car a quick squirt, and you want to check the knock, you've go 10 seconds before its pushed off the graph. Press I think the left or right key will pause.

I'm running 210rwkw, with your same setup.

About to upgrade to a GT30...