Apexi PowerFC now running without MAF sensor
 

After considerable development of my MAF sensor delete project as detailed on 22b, AndyF and I have applied it to the PowerFC and successfully have it sorted and running perfectly, power graphs and results will follow as they become available but should be quite special :D It will require a little more development to work with Ecutek mapped ECUs but I intend to develop it further not least to get my own car working with it.

With the PowerFC application it runs full speed density with temperature correction, as well as adjustable retard and enrichment for high intake temperatures.

Throttle response, smoothness and consistency are all good.

You can now run any intake you like without concern for fragile or restrictive MAF sensors.

Long FMIC pipework, wild dump valves and ported shroud compressor housings will not upset anything.

Thanks go to amongst others, Andrew Carr for supply of populated circuit boards and advice.

Hopefully in the near future PowerFCs will be available mapped to speed density, slightly prolonged mapping may be required for early examples as well as the extra hardware involved.

thats good news
MAF sensors on subarus are a bit fragile and anything that sorts that out is a fullon bonus

Hmm - Having mine 'fc'd by Andy in the next few weeks, is it worth considering this ?

And would it be helpful to 'the cause' ?

Mark

is this just a software change on the power fc or is there an addon plus software change :) as would be nice to add a different induction kit to mine and get rid of the K&N

congrat's to you john and andy for that!!!:D good yin lads:D

I was considering the power FC for my evo but was warned off it by a Professional Rally Outfit. They said that it was pants and didnt have real-time mapping capabilities. However the ECU is only as good as your mapper and there are only two in Britain who i would trust implicitly. Choose your mapper very carefully as it could mean the difference between your engine running smoothly or exploding into ££££'s.

All the best mate. :)

Jono

Involves an addon box which simulates a MAF sensor based on other sensors, and then the PowerFC maps are adjusted to suit. For the PowerFC application the ECU is adjustable enough that the addon box's calibration is fixed and simple, which is why the maps are adjusted. For ECUs such as my JECS, the addon box will be the one that is mapped primarily which is why further development is required. Hope this is clear ;)

Don't know what the PowerFC is like for the Evo, but there are no issues on Subaru applications... apart from using a MAF sensor. It does have real time mapping capabilities and the manners are as good as OEM.

BTW, in many applications a MAF sensor is actually better, when you work out how to simulate one you realise how good they are in many respects apart from fragility and strange airflow patterns.

i know what ecu i'm getting next;):D

was just reading your thread on the 22b :) top stuff, will ask andy about it more when i see him on saturday.

which one then ;)

oh darn, i've went and forgot now:confused:





;):D:p

I intend getting some miles on this conversion before offering it as the standard set up with my Power FC's, just to ensure there are no hicups !
It will be a bit more expensive than a MAF based install as there are additional parts and more intensive mapping requirements, however, the gains I'm sure will be very worthwhile.
This conversion can be retrofitted to cars currently running MAF on the Apexi and will be in Scoobyshop soon.......

Thanks again to John Banks and Andrew Carr for the development work :)

Andy

Sounds very interesting. I'll keep my eye out for it in the scoobyshop.... if it's avaliable as a DIY install and map option.

Tony.

This sounds a great job done, but what are the advantages of removing the maf?
Is the engine more tractable, smoother or better 'managed' at high revs or some other benefit? Is it to remove simply the possible unreliability of the maf?
You both feel this is a good move forward, but maybe I've missed the point of the exercise, sorry if I have.
An AndyF FC is on the Xmas list for my Sti v3 hill climber, hence the question.
911

MAF sensors also have flow limits as well as giving odd readings when the inlet tract and intercooler or dump valve are modified, primarily from flow pattern disturbance or reversal. All of these are inevitable on a high power car.

For example, with a FMIC when the dump valve dumps as some do in a pulsatile manner quite a lot of trapped air at high boost backwards through the MAF the whole car can jerk, this can happen mid bend which can be a bit tricky and unsettle the car. Ported shroud compressor housings can lead to such weird airflow signals on lift off that the car becomes undriveable.

On standard cars MAFs are unbeatable because they respond better over time to changes in VE (as well as mods for the same), they give far neater transient response to allow emissions standards to be met, and they are carefully mounted to be vibration free with resonators and protective/airflow straightening screens before them, with small volumes of low boost air to recirculate through a softly and smoothly opening dump valve.

Double airflow through such a setup and you're in trouble for the reasons outlined.

I agree with John here. Up to say 330-350 bhp where you retain the std intake pipe and a known good filter, then stay with the MAF would be my advice.
As soon as you want to start freeing off the intake system, running higher boost or a big turbo then consider the benefits of the MAP based system.

Tony - It took John and I the best part of 3 days of calculations and mapping with FC Datalogit to combine the MAP convertor with the idiosyncrasys of an ECU primarily designed for MAF based loading.
The MAP based Apexi PFC's available for other models have a different method of load calculation which lends itself to the relatively simple mapping technique of running through each pressure zone (as per the link)
This hybrid set up is much more complex and as such I will only be offering the conversion package fitted and mapped.

Andy

Excellent, and thanks for all the detail.
To have the 'MAF free' version available as a retro fit to the FC would be a boon as people seem bored when 350 is found and go off looking for 400bhp.
Very interesting stuff.
911

Congrat's guys ;-)

Congrat's too... here we're waiting for a MAP based maps solutions. But on STi7 PowerFC doesn't fit. I hope you'll find a same solution for genuine ECU

Sounds like something for me to keep on hold till the future at the moment then - I'll keep an eye on developments...

Andy - I'm not sure how much power will come from my spec, but it is running a 57i induction kit and the Hybrid FMIC, so it may be a more suitable solution than the MAF - I do get a bit of a rough idle and some odd effects on throttle off occassionally, but that could be due to the current 'incorrect' mapping...

Thanks,

Mark

Great news guys, this means I will not have to wait for Apexi to bring out a D-Jetro version of the Power FC for the Scooby. Better get my Pro spec cpu version ordered then.

Andy will you be able to do this mod when you come down South ( Andy / Peanuts is trying to arrange a date at the moment ) looks like there might be 4 of us to have FC's mapped, and a couple of AVC-R's aswell.

Colin.

Not sure on the timings of an 'off the shelf' system Colin. I need to test it under the full range of conditions such as a 2hr hot traffic jam, drag racing, top speed running etc. Winter morning cold start will need to wait a bit longer ;)
With my current backlog of maf based installs, not to mention getting my new scoob sorted out for totb, I doubt that it will be available this month. Early August is looking good :)

Andy

Early August would be ok by me. Got loads still to do on my Scooby as I might have a couple of magazine shoots coming up ;)

Obvously your Scooby has got to come first for TOTB :D

Colin.

Sounds very interesting. Would you charge your full mapping cost to tweak one of you current maps for this Andy?

Oh, and YHPM.

Not sure on price yet Ben, it is time dependant. I still need to iron out all the zones that some people will no doubt use (god knows why !) such as WOT at 750 rpm in 5th and cruise at 7000 rpm !

Andy

:eek: :eek: :cuckoo:

Yes I know :D but if I don't...... they will !!

watch out for those camera's when your cruising at 7000rpm in 5th:eek: ;)

Shot in the dark
 

Hi all was this ever launched or was it merely a trial