RX794

Here's the deal, APEXi sells a map sensor upgrade for the Power FC, you can change the settings for it. Also if you wanna run more boost than the FC MAP goes to, remember that the timing will stay the same and all you gotta do is add fuel for more boost with some sort of AIC that has a MAP that can control additional injectors within the specified level of boost you wanna run.

Want2race

I just bought that exact type of unit...
It comes with a MAP sensor and a tac reader.
Then based on those two variables and your settings it add fuel fuel as rpm and boost increases... It came with a 5bar map sensor so it would work well on any turbo...

ONly downfall is I decided soon after to get a Haltec and I might aswell sell the aic... If anyone wants it drop me an email...

vosko

iTrader: (4)

i'm 99% sure the stop sensor reads upto 1bar (14.7psi) over that you have to purchase the apexi pfc boost control kit with comes with a new sensor and solenoid. that allows you to run up to 2bar of boost. i know www.srx7.com has them in stock

vosko

iTrader: (4)

the kit is $399 from www.srx7.com it comes with a 3bar map sensor and new solenoid for the pfc. you didn't have to post this topic in EVERY section

lesd

The pfc can use many boost sensors. It even has a place to put in the signal calibration ( how many volts per boost unit ).You don't need to get their boost control unit to get a better boost sender.

The maps, on the other hand, may not go up high enough.

-Les

MeLoco

I find it funny that xs told me 1 bar with stock map sensor.

MeLoco

AHMEN!!!!

newRX7fan

iTrader: (1)

>i'm 99% sure the stop sensor reads upto 1bar
>(14.7psi) over that you have to purchase the
>apexi pfc boost control kit with comes with a new
>sensor and solenoid. that allows you....

That 1% got ya. The max pressure on the PFC map is 2.4 kg/cm^2 absolute, which is 19.4 psi. That is higher than what the stock map sensor can *accurately* read, which according to the PFC manual is 17 psi.

SPOautos

The stock map sensor is good for 17psi, above that you need the Apex sensor that is good for 2.00kg/cm2 which is 29.4psi. I dont know how much the Apex sensor cost but bet that you need thiers for the Power FC to control the boost right. They seem to have made the Power FC very proprietary. If I was going to be running over 17psi I dont think I would skimp on the boost sensor that feeds the core information that you entire computer is tuned around!!!!! Especially not for a couple hundred $.

BTW - The sensor info is according to Eric Hsu, the Chief Engineer for Apex Intergration, Inc

Later,
STEPHEN

RX794

A map sensor sends information to the computer by voltage, so therefore if 2 different companies MAP sensors both read 3 bar for example, if the voltage readings on both are the same, then you CAN interchange them with one another, so brand name doesn't really mean that it's not gonna work, or that another boost sensor is bad.

lesd

I seem to recall that the PFC had a variable number you could set for the voltage gain of the PAM sensor, allowing you to pick from a wider variety.
I sold the PFC, so I don't have the manual any more.
-Les

jumprdude

Here's my $0.02 after having played around with my PowerFC, read the instructions and taken into account other credible sources, and thinking about the problem for a very brief 15 minutes or so...

These are my assumptions:
Stock MAP sensor only detects up to 1.2kg/cm2 (17psi) of boost. This has been mentioned by Eric Hsu, and is in the Commander instruction manual.
Standard PowerFC injection maps only go up to 2.0kg/cm2 absolute (or 1kg/cm3 boost), in 0.1kg/cm2 increments. This is by looking at base maps, and verified by seeing (with the Map Tracer function) which map point I am using given a certain amount of boost (please if someone could verify that this is true, and that the PFC does not do something funky like increase exponentially in the absolute pressure map tables)

Therefore, to be able to get the PowerFC to control over 1kg/cm3 of boost we need to update the MAP sensor, as well as find a way of getting the PFC maps to go above 2kg/cm2 absolute. Simply updating the MAP sensor is not enough, as it now screws up the MAP sensor to boost level calibration that the PFC uses to interpret the MAP sensor. Since Apexi sells a boost kit one can only deduce that there must be some means of getting the PFC to recognize the higher limit MAP sensor, and to switch maps and calibration accordingly. I do not see any means for doing this in the PFC commander menus so I deduce that it is either a change in the base maps, or that there is another way that the boost kit tells the PFC to switch over. (I did see an adjustment for a PIM voltage in the Commander, but I can't imagine that this is the "right" way of controlling a properly designed boost kit, all the PIM voltage adjustment is for seems to be relative base map injector adjustment based MAP sensor reading. It doesn't seem like it would change the boost level to MAP voltage calibration settings, unless the numbers indicate not injector settings but calibration offset from original).

I was told that the single inline 5 (or 3 depending on what version) pin connector beside the connector where the commander attaches is for the boost kit. Maybe by virtue of attaching the boost kit (resulting in voltage being returned on one of those pins) to the connector is what causes the PFC to switch maps? Someone care to try? And if it does switch maps, does it extend the range, or squeeze the range into the 20 cell range of the PFC? Would we have to re-map every single cell if we were to use the boost kit?

Also, why does Apexi include a solenoid with their boost kit? Is the stock one inadequate? Will it break eventually under too high of a boost level? Or does it not flow enough air to be able to reliably control boost? Or maybe its all just a marketing ploy? Is the solenoid what's controlled by the other 2 pins on the connector (3 for MAP sensor, 2 for solenoid)? If so, why did some versions only have 3 pins?

So, in my 15 minutes of thinking I have determined that there is more to this than meets the eye, and simply attaching a universal 3bar MAP sensor to the stock location using the stock wiring may not necessarily work.

lesd

From the user manual:
" [setting ] --> [ PIM volt ]
This function is used when the boost levels of a particular car exceed the measuring capacity of the existing pressure sensor. In this case a new pressure sensor must be used....."Sounds like it's for changing the sensor to me !

It shows how a new sensor can be calibrated into the pfc. They use a table of percentages. The table should allow you to add a sensor with non linear pressure to voltage response. It makes reference to getting richer when the voltage values are changed, but I don't think it is changing the fuel maps. After changing the PIM voltages, you are not changing fuel maps, but the mapping of the MAP sensor voltage to actual pressure, that number is used to calculate the map cell that will be used.

As usual, I'd say call them and ask to double check.
-Les

NYRX7

I don't mean to dig up such an old thread, and I didn't want to create a new one because I think others coming across this may have the same question...if I have a gm 3bar map sensor and a greddy profec b boost controller can I raise the boost level over 20pounds or do I need to get the power fc boost kit ?
If I have a GM 3 bar map sensor and a greddy profec B boost controller will I be able to run 20+ boost

arghx

iTrader: (3)

You or someone else needs to set the MAP sensor calibration in the Datalogit. If that's already been done you need to make sure you set the boost level high enough in the PFC so that your overboost fuel cut is higher than the boost you intend to run.

You have two options. You can effectively disable the overboost fuel cut completely. For that you would set your boost setting to 2.00 and be done with it. So go into the boost control screen of the Commander, select the first option and set it to

Pr 2.00
Sc 2.00

and then you will basically never hit fuel cut. That's the easiest way to do it, but I prefer to keep a fuel cut in the event that boost control fails in some way.

Overboost fuel cut occurs ~.25 kg/cm^2 higher than the boost setting in the boost screen of the Commander. So if you wanted to run 21psi:

first convert 21 psi to kg/cm^2. there's 14.22psi per kg/cm^2

21 / 14.22 = 1.47 . round up to 1.50 kg/cm^2 . subtract .10 from that and put that in as your boost setting. so set boost to 1.40 kg/cm^2 in the commander and you will fuel cut at 23psi. I'll spare you the complete mathematical explanation.

NYRX7

Arghx, thank you so much for your detailed help.