Power FC D'jetro, whats in the box?

[Jake1992]

Im trying to buy all of the things i need to get my car started.
94 jdm s14 zenki, 95 kouki conversion with 95 sr20det in it.
Some people say i need the map sensor, but then again searching
on google i see some people have this air temp sensor in there intake ?
Do i need it with D'Jetro ? Hows the wiring go ? it conects in white plug
( where boost kit has to go )??

thanks !

[Kingtal0n]

It is not necessary, only recommended. The problem is, if the tuner does not know or understand the relationship between air temperature and mass, you may wind up running the engine quite leaner than anticipated on a very cold day- without the OEM air temperature sensor configuration to compensate.

Generally it is used to pull a few %'s of fuel when the air temp gets hot. that means tunes are usually "too rich" for full temperature situations, and the air temp sensor pulls out the fuel to compensate as the air entering the engine begins to heat up.

also, Dont use the Power FC boost control kit, use a stand-alone boost controller such as greddy Type-S or Profec-b.

the D-jetro PFC uses a map sensor that should be used on engines that make more than 400~ horsepower. If you are making less than 400~ horsepower, you should use the L-jetro Power FC, and a Z32 maf sensor.
Unless for whatever reason you need to eliminate the maf sensor (cosmetic, intake plumbing length, etc..) then by all means use the map sensor. Map sensors are just a bit tougher to tune, and like I already mentioned, they cannot compensate for changes in air temperature without the additional sensor. A maf sensor can compensate for air temp changes.

[Edwin562]

your better off saving up and buy everything at once. the whole kit....

[jspaeth]

It is not necessary, only recommended. The problem is, if the tuner does not know or understand the relationship between air temperature and mass, you may wind up running the engine quite leaner than anticipated on a very cold day- without the OEM air temperature sensor configuration to compensate.

Generally it is used to pull a few %'s of fuel when the air temp gets hot. that means tunes are usually "too rich" for full temperature situations, and the air temp sensor pulls out the fuel to compensate as the air entering the engine begins to heat up.

also, Dont use the Power FC boost control kit, use a stand-alone boost controller such as greddy Type-S or Profec-b.


I have been running PFC D-Jetro for like 3 years now..........works perfect.

The temperature sensor that comes with the kit is VERY slow response.

I have mine installed in the cold pipe, RIGHT before the throttle body.


IF I drive the car around and don't come to a stop (so as to not allow the engine bay to heat up), the temp sensor always reads roughly equal to the outside air temperature.

Even when I floor it, and go into boost, the temperature sensor does not change. It simply does not react quickly enough.


However, I believe this is a good thing. Due to this effect, I am able to separate out 2 different effects:

1) Effect of "starting air temperature" (i.e. changes in outside air temp.)
2) Effect of "air heating up due to boost" (i.e. air temps going up transiently due to boosting the air).



Since the sensor can only do effect #1, I use the Air Temp vs. Fuel Correction Table to add/remove fuel for cold/hot weather.

I cannot directly detect effect #2, but the effect of the turbo heating up the air should be that at any given boost level/RPM level, the air is heated up a given amount. Under this small assumption, the effect of the turbo heating up the air is taken into account in the main Injection Table via datalogging/tuning of the individual cells.


Again, the net effect is that I use the air sensor reading only to trim fuel as related to changes in the "starting air temperature", i.e. the outdoor air temperature.


i find that it works very very well. You tune the car at temperature X, and then remove some fuel at higher temps and add fuel for lower temps. In practice, this can be done by using known rich values, and then scaling the numbers back to give you what you want.


The hottest temps I see (air temp) are around 35 C, so for all temps above this, I leave the value the same. This way, if the sensor heat soaks in a parking lot on a hot day, it doesn't remove any additional fuel.


If you get into this stuff, one thing that you will become conscious of (which I am) is paying attention to the temperature reading when you start the car up.

If the displayed temperature is higher than about 5-10 C over what you know the outside temp. to be, do NOT beat on the car (obviously depends how aggresive your AFRs are). If your car is tuned with 11.5-12.0 AFRs in high boost, and you boost the car when it is 10C out but the sensor is heatsoaked and reading 30C, you could be in trouble.


Basically, the air temp correction works well, but only as well as the person who is using and observing the unit. For me, my tune is very very safe on the fuel side of things, so I am not too worried about 1-2% differences in fuel. I am not sure how perfectly this works across the whole map (i.e. are the same corrections required at a new temperature needed to keep different parts of the map in check with the reference state at which the enitre map was tuned). If I had a car that was tuned more ambitiously (11.5-12.0 AFRs under boost), I would probably run 2 or 3 different maps entirely..........one for winter, one for spring/fall, and one for summer....just to be safe.


Also, I agree with you on the boost controller. I have the PFC boost control function turned off. I run an AVC-R in tandem. The AVC-R and PFC each have their own dedicated pressure sensor. The two are off by about 0.02 bar, but that is a minor effect, and likely just a minor calibration issue. As long as you tune off of the PFC sensor, it doesn't matter really.

[Jake1992]

Well guys , i bought the car with stock ecu installed and a power fc with it ...
The rumour going around is that no one could make it work with the power fc, the car has a z32 maf installed now, when i finally got my datalogit , i found out that in setting 3 there was no maf options but map so i figured its a djetro. Thats what the datalogit reads from the PFC.

So i dint buy one i just have one...

how does the temp sensor wire up ?

[jspaeth]

Well guys , i bought the car with stock ecu installed and a power fc with it ...
The rumour going around is that no one could make it work with the power fc, the car has a z32 maf installed now, when i finally got my datalogit , i found out that in setting 3 there was no maf options but map so i figured its a djetro. Thats what the datalogit reads from the PFC.

So i dint buy one i just have one...

how does the temp sensor wire up ?

Confused.......how is it D-Jetro but with a MAF installed and wired up?


Independent of that, wiring up that air temp sensor is really easy. I think there are just 2 wires, one of which is a ground, and the other which you have to had a pin to the ECU.......really not bad.

Do a search on here about it..........I did a write up a few years ago

[Jake1992]

Confused.......how is it D-Jetro but with a MAF installed and wired up?


Independent of that, wiring up that air temp sensor is really easy. I think there are just 2 wires, one of which is a ground, and the other which you have to had a pin to the ECU.......really not bad.

Do a search on here about it..........I did a write up a few years ago

Thanks , look what i wrote.
I bought the car with the stock ecu installed, and got a power fc with it. just the ecu, nothing else. Bought a commander, and datalogit.
when i replaced the stock with the Power Fc the car wouldnt start. So i kept looking to change my maf settings (thinking it was Ljetro) but there are only map options. So from that point i got to know it was a Djetro. I am getting a 3 bar halltech map sensor today , would i be able to start without air temp sensor ?

[jspaeth]

Thanks , look what i wrote.
I bought the car with the stock ecu installed, and got a power fc with it. just the ecu, nothing else. Bought a commander, and datalogit.
when i replaced the stock with the Power Fc the car wouldnt start. So i kept looking to change my maf settings (thinking it was Ljetro) but there are only map options. So from that point i got to know it was a Djetro. I am getting a 3 bar halltech map sensor today , would i be able to start without air temp sensor ?

Sorry, my bad. Not sure about that. You should be able to easily order the temp sensor from Apexi. Not sure if it will start and run properly without it.

It is also a Mazda part number.


Look up a thread I made about Power FC Intake Air Temp sensor install............

[Big Zee]

so the d-jetro kit does not come with its own air temp sensor ? just the air pressure sensor ?

[jspaeth]

so the d-jetro kit does not come with its own air temp sensor ? just the air pressure sensor ?

If you buy it brand new, it certainly should come with the temp sensor and a pressure sensor, I believe.