PFC Users with DW 740cc, I need your help

[kernel]

I have big problem setting up properly my S13 RedTop PFC with theses injectors.

I don't know what's the lag time on my set. DW told me they were using stock lag time (0.58ms, +0.00ms on PFC injectors setting)

I tried it and my idle is wayyyyy lean. I have to set lag time at +0.50ms to have a good idle with ~14.7 AFR.

I'd like to know what's your lag time for them ?

Also, when setting up the lag time, should I do it while the self learning idle ?

Should I wait till operate temps (80-90 Degres C) is reached before doing the self learning ?

Also, when i take the car for a trip, it feel sluggish, bad throttle response.

I got told that it might be the water temps correction so I set them to 1.00 at 50C+ & 80C+

I have lots of question about setting the units so if someone could take time and help me, I'd appreciate.

Thanks

[GSXRJJordan]

Yeah, the PowerFC isn't the most friendly thing to set up, especially 'cause it was designed to be fairly dead without the PowerExcel software.

Like I told another PFC user not too long ago, shoot an email or PM to Steve Shadows ([email protected]). He's a great local tuner, and has recently been doin a few PowerFC's. I'm sure he'll drop in with a few hints if he sees this post ~

[kernel]

thanks for giving me his information, I sent him an email. I hope in getting answer back from him.

If there user that work with 740cc from DW, I'd like to know whats your lag time

It would, at least, give me some setting to try and start from.

[chmercer]

DW injectors are like... uhh.. yeah. theres a reason they cost nothing

[steve shadows]

Originally Posted by chmercer

DW injectors are like... uhh.. yeah. theres a reason they cost nothing

I am currently using a set of 810cc inj i got from them (need 1000 lol) and Luke is using 555cc ones they put together for us.

They are....ok.

The problem I have noticed is because a lot of them are 're-drilled' they spray a lot more fuel all the time. SO much so that inj lag time corrections can not correct for them in some cases.

I have never had that problem with 740cc or 555cc inj from Power Enterprises or Nismo, but I have also not used a whole swarm of D-werks injectors so I can't make a totally fair assesment.

If you have a specific question about where the inj setup should be or correction, I might be able to help, Im getting re-freshed with the PFC lately even though Im kicking and screaming about using damn hand commander lately. Haltech FTW, AEM eh, PFC eh eh.

anyways hope everything works out either way.

thanks jeff- for the props : )

[mayco_86]

Thats why I only use NISMO Injectors. But DW are reasonable with the price. You get what you pay for.

[tchenku]

munkfu - what color's your injectors? this is from DeatschWerks: red = 0.7ms, purple = 0.58ms. i think in your case, your lag time is 0.7ms (if they're red).

0.7ms is what i use and i have no problems or complaints about DW injectors!

[kernel]

tchenku: I currently have the purple one, I'll try the +0.58ms lag time like you said. But do you mean +0.00ms in PFC or +0.58ms , because I read that the PFC setting at 0.00ms is 0.58ms (stock setting for 370cc injector).

Anyway I'll try the +0.58ms to see what'll happen.

Thanks

steve_shadows:

Well, I have played alot recently with the commander, it get very annoying playing with it like a gameboy.

About the setting, I know where to go in commander and know it very well. I have trouble with that units since I bought it, lol.

The bad thing is I can't get a good idle, it always bounce or it idle at 1200rpm when I come to a stop even when the car is warmed (65-80 C).

I do the self learn idle procedure plyaing with INJ lag time to get a good 14.7 AFR at 800rpm, then I wait 10 minutes, then shut down the engine, restart it and i get a crappy idle at 1200-1300rpm and richer AFR (12.5 to 13.7)

Should I do the self idle procedure with the car already warmed up ?

Also with the wrong lag time, my engine response is horrible...my car come leaann so bad that I have to rev to 2000-2500rpm to be able to start from a stop.. Even if I play with INJ Lag time it come to worse, either I get bad AFR at idle or at all rpm and worse response.

I must do all the stuff on my own, I have already some knowledge about tuning but I'm not a pro..I've done my swap by myself and all the tuning on it
(I went from a safc2 to powerfc) I have wideband in car. I spent alot of hours trying to get the right setting but it always come to a reset then redo the whole stuff...that why I came here to ask help.

There's no PowerExcel dealer nearby and I'd have to do a 8h road trip to get one..

So I hope to see someone explain me correctly what to do to be on the good way.

[s13silvia123]

obviously we all are having the same problems correcting them is not so simple to use the PFC as what others may say. tech support on these aint so much help cause its alot harder to use then the SAFC. some of us dont have a powerExcel dealer nearby as stated above. it'll be great to someone with more knowledge about the PFC most of use never expected the PFC to be this difficult to consult with. my suggestion is to help each other out and what could be the outcomes.

[johngriff]

<noobschool>

As far as the PFC Idle issue is concerned.
Advance the timing in the commander to 17-20adv around idle.
Legnthen the IACV Hose, then adjust the IACV nut in between runners 2 and 3 to correct the airflow.

Redrilled injectors flowing alot more fuel all time time, time time? lol.
High Impedance Injectors are high impedance injectors. Total cylinder/fuel volume is dynamic not static. 740cc's should be ok for idle using a style 1 injector. But they are high impedance, they are crap, crap solenoids, the lowest you will "actually' get is going to be 1.5ms.

Style 2 (SARD) is like cheating, they are so cool, way better nozzles, tighter wrap on the solenoids, giving them a great lag/response time.

In short.
You Lag time is the EXACT same as the series injector you are using, if the injector body/solenoid was originally a 370cc injector, the lag time will remain the same because they have only enlarged the pintile tip, not replaced the internal solenoid, to some "majic one".

To further correct your idle. You are probably not going to ever idle at stoic, why you are trying to do that, i dont know. Maybe preheat the cylinders at a stop light (ROFL).

12-13af/r at idle is pretty damn good, some like it in the 10's.

The PFC is hunting for idle correction using the map for 370cc injectors (DUH), you need the dataloggit to reprogram for that. Try turning idle correction off in the setup menu.

As stated above, the best way to keep control of your idle with the PFC is going to be legnth of IACV hose, Adjustment screw and Ignition timing.

Oh yeah, Idle fuel pressure can make small changes to your total fuel at idle if you are up against the wire (1.5ms)

</noobschool>

Originally Posted by s13silvia123

most of use never expected the PFC to be this difficult to consult with.

No, I believe, I posted in threads you were in multiple times, explaining that the PFC was a big pain in the ass, unless you had good previous experience, or a tuner nearby. Myself, and other forum members, all referred you to multiple various tuning options.

Tuning the PFC is well documented online. You are not cracking some secret code. It is a bitch. I did not hijack your thread to push a product, now you may see, I was honest to god, trying to help you.

[kernel]

thanks alot for explaining

About the lag time, well I tried the stock lag time and it so lean, to make it idle at ~13 AFR, i need to make a correction in fuel map up to like 150 and the throttle response is so bad..

I can't do at all the idle procedure with that kind of lag time, the car shut down on idle because it too lean. (0.00ms in PFC is 0.58ms for stock injectors I got told)

I tried alot of different lag time and it come always to the same end, bad throttle response. I know under 80C it could be the water correction that do it and tried few setting and never worked or I was totaly too rich and the engine response was finaly there.

About the idle correction in setup menu, I don't see that. It can maybe turned off with PowerExcell ? I have a PFC for red top.

Well, thanks again for the info. I knew that I still using the 370cc body with 740cc from DW but I didn't know if it still has the same lag time. I'm currently a student as mechanician so..I can't know everything. I hope my explaination are good and you understand well what I'm trying to say. It hard to help someone when you don't know what he talk about really.

[steve shadows]

make sure the

boost control option is turned off (its a japanese character)

as well as

the idle motor option which i can't remebre off the top of my head what its called.

its in the MISC menu setting.

if i get a chance to grab the commander from my friends car

ill take picutres with screen shots, also did you email me?

ill be happy to walk you through the propper correction procedures.

i dont like the % correction on the commander, its doo doo.

Actual injector change is better.

PS. 13:1 AFR is not too lean. 14.7:1 is just fine and I frequently tune turbo cars to 15.1:1 afr on 91 octane for part throttle adjustment.

Soundsl ike an issue with something else?


Another thing I have noticed is overly high fuel pressure at base

Happened with a friends car recently, the person who tuned it before me failed to check base fuel pressure, the car was getting horrible gas milage and response was stunted drastically as well as low end torque although the AFR's were in the safe zone.

FP makes a difference as well.

[johngriff]

Just to explain lag time real quick (people like steve, russ, and myself need to write a faq on these basics).

A fuel injector, is constantly supplied 12v power. When the fuel computer desires the injector to open, it grounds out the injector. So. Power comes from the car battery, to the fuel injector on one pin. The other pin, is wired to the Fuel computer/ecu (NOT SAFC).

From the time that the fuel computer grounds the injector, to the time the solenoid of the fuel injector "actually opens" is the lag time. A solenoid is like a piston inside of a shaft, that is wrapped in wire, like an electric motor or magnet (uber basic).

Depending on how many amps are being drawn, how big the solenoid, how many times it is wrapped (coiled), and the guage of the wire, will effect the time between the ecu grounding the signal wire, the solenoid actually opening.

The Fule computer calculates Lag time to keep the injector open at the right time, and for how long, compensating.

Apexi's setup is correction +/-. So, when set to 0.00ms, the PFC is calibrated for a solenoid the same as the OEM 370cc. In the case of the DW Injector, it is still a 370cc solenoid, so the lag time (correction) will remain at 0.

When purchasing (upgraded or different) injectors, make sure you have your new lag time IN WRITING. This can make/break/blow your setup.

To configure new lag time in the pfc:
0.00 = 0.58ms

370cc=0.58ms
New injector (example)=1.5ms

1.5
-0.58
---------
0.92

So you would assign injector lag time to +0.92ms to add correction for the new injector over stock.

This is a little O/T but this needs to be covered for the sake of search indexing.

[KawBoy]

Good info.. Subscribed