Hello

how does standard POWER FC (for v5/6) base fuel map compare to Standard JDM STI v5 ECU fuel map ? are they the same ? or one leaner than the other one ?

an other question, how does the PFC boost duty cycle works ? what is is all about ? (values on the right of boost presure settings)

 

Haven't done a version 5 Apexi but fuel maps from Apexi tend to be slightly on the rich side....
The values to the right of the pressure settings are the solenoid duty settings...You need to set your desired boost in the pressure setting and then adjust the duty until you get decent spool up and a nice boost profile at the boost level required...

 

as Martyn said.. also the ignition is fairly advanced depending on what fuel you are running..

 

thanks guys. I have worked a retarded ingnition (you helped me 4 month ago simon )

but still haven't fitted wideband sensor. well if it is a bit richer, it is all OK then. I will fit my wideband shortly and do proper fuel map soon

still haven't understood the boost duty cycle principle thought
I have done 4 settings. they do work. but I would like to understand this a bit more

 

I thought the name was familiar..

I'll email you

Simon

 

no I won't.. can't find your email address

Email me Simon @ JollyGreenMonster.co.uk and I'll take you through the boost control.

Simon

 

It is fairly simple , 0 - 100% or 0 to full boost if that makes it easier...
As I said before set your desired boost in the boxes to the left ie 1.30 bar , then adjust the duty cycle to the right of that box upwards until you acheive 1.30 bar with good spool and little drop off....A small overshoot is ok say .02 bar....

 

Email sent Simon

MartynJ, 0% for full boost ?
what do you mean by good spool and little drop of ? you mean you can alter how laggy the turbo will be ? by drop of you mean the duty cycle will change the way boost presure drop of on high revs ? or drop of just when desired presure is reached? (boost spike)

 

No I said 0 (No Boost) to 100% (Full Boost)....
The duty setting has a lot to do with not just how much boost you make but how fast and how stable the boost is...A duty setting to low for your desired boost will make the boost slow to build to target and may tail off at higher rpm...
A good setting will make boost nice and early and will hold boost where allowed by turbo size and actuator condition...
To be honest my advice due to your limited knowledge would be to allow a proffesional to tune it for you and leave it alone...

 

There are no professional in my country. So I have to learn
I have some tuning knowledge. but this dutycycle thing is totaly new to me. (my previous turboed car didn't have such settings : EMU + dual solenoid boost controller)
your explaination helps. even if it still doesn't explain what would happen if I would just enter 100% ! as from your explaination I understand that higher the value is faster and more stable the boost would be. now there must be a reason to lower those figures. do I smell "boost spike" ?

 

replied to your email..

 

To understand why you need to have a basic understanding of how the valve works , 100% will mean it is spilling off all the time meaning maximum boost all the time...
You only need what is reqd to make your target boost...

 

Ok, I see know.

but then, does that mean that first column where you fill boost value is informative only ? only the duty cycle will change boost value ?
I think there is still something I'm missing here to understand fully how the full system works.

 

thanks Simon for your last email.
this is all clear now. ready for a setting session

 

no problem

 

quick notes.

I have noticed that minimum boost duty cycle is 20. PFC doesn't let you go for lower values.

other thing, there is an other column value on the right of boost duty cycle. those value can go up to 255 and connot be edited (they change themself). what those values are about?

 

no point going less than 20%, as solenoid is shut... you should only get actuator pressure..

the number is to do with the closed loop control of the boost and only for reference..

Simon

 

yep, I have used 20% boost duty for my lowest boost value : 0.65 kg/cm² . I first thought 0% would be fully closed. so everything is OK

that last column number are for closed loop reference, ok. but what do they say ? do you have info on this? just curious while I'm still on that screen...

 

I noticed that when boosting to 1.1 kg/cm² I have engine check light at high revs. saying that my injector max out.

here are values :

RMP: 6500
Injector: 100%
Knock: 12
MAF: 4.42 volt
boost 1.11 kg/cm²

I use standard apexi fuel map so I'm a bit surprised. I first thought MAF sensor was reaching it maximum. But it is apparently not
howcome injectors max out ??

 

your maf will be okay for about 450bhp iirc

at 1.1bar you wouldn't be maxxing the standard injectors if mapped to the AFR which tends to be used over here in the UK. The standard map is rich..
there are two very basic relationships / ways of mapping.. rich and lots of timing.. or leaner and slightly less timing.. going leaner and less timing you can get to around 1.3bar on your car without maxing the injectors until 7500ish rpm.. however you cannot therefore just lean it off as you would need to monitor knock and sort the timing.. but this is the reason for maxing the injectors it is running rich to try and stop det.

Simon

 

that would mean that the standard apexi map is WAY MUCH RICHER than standard ECU then (as standard boost is 1.1 bar on standard ECU), hmmm I really need to plug my wideband ASAP and check those AFR value then.
I have setup safe ignition timing to cope with our low 95 octane fuel. I don't get more that 15 knock value

also, It seems my maf sensor has been changed to a nissan sensor. I will need to take this in consideration. is there a quick way to correct sensor value as it is not original sensor ?

 

how do you know it wasn't maxing out the injectors on the original

 

In fact you are right. I don't know. Just asumed that no factory ECU would go over 80% injector duty as it is suposed to be not good for injectors. so I've been surprised to discover I do max out with apexi standard fuel map at factory boost at 6500 rpm (still 1300 RPM to go to redline while injectors are already 100% )

hence why I first thought MAF sensor was responsive of it. but it says 4.42 volts only...

 

this different maf is also possibly not helping..

you need to get yourself a wideband so you can tune it knowing what the fuelling is doing

Simon

 

I have one LC1 sleeping in the box it seems I'll have to weld that bung asap !
(I was waiting to get the FC datalogit or FCtune box)

 

no need to weld boss etc..

remove original lambda sensor in top of the downpipe..

fit wideband in there..

go to ETC--> Function Select --> O2 Feedback and turn it off.. (down arrow on the symbol).

However agree it would be wise to wait for Datalogit etc..

I use datalogit, I have looked at the software of FCTune but not used it..

Simon

 

ohhhhhh !!!
didn't know that.

but now I have questions again (yeah I know I always have questions...)

- is this for temporary use only ?
- doesn't narowband sensor needed for closed loop mode (to get proper iddle)
- doesn't standard lambda location too close to turbo ? (bosch wideband sensor is very sensitive to heat and is better fixed as far as possible from turbo).

I'm might finaly order FC datalogit as I don't know when FC tune box will be available (was waiting to see how it goes while I was still looking around for witch water/meth injection to go for). Too much things in my head !

 

the narrowband is used to trim the fuelling on idle and cruise..

it is better to still have the narrowband in use but you are tuning the fuelling etc..

no it is the perfect location for it.

 

yeah I see your point . as I'm tunning fueling, I don't want the ECU to trim/correct/confuse me more than I am ! lol
when I'm happy with fueling, I'll just plugback my narrowband sensor and drive happy.

the LC1 was first meant to be permanently installed thought. but well, it is not needed, It will save his lifetime

Thanks again for your help Simon

 

yes..