Rb26 Pfc Working On Rb20/rb25

[Cubes]

No more f**king around with Airflow curves, and Maf settings, as MAP sensors are universal on all cars as they only read pressure, regardless of pipe size, etc.

Any one have a djetro base map I can check out via the datalogit?

The afm pfc averages the two afm values and then derives the load value via a 32k constant. The single afm pfc's simply use a single afm value to derive load via a 16k constant.

I assume the djetro rb26 pfc runs to map sensors due to the rb26's individual throttle body's for each port. On the rb25 no doubt a single map bridged would do the trick. But why bother.. Just buy the kit.

Mafia.. Very keen to see the rb20 and rb30 back to back. The hks3037ProS would = poo on the rb20 unless you run the .6 scroll.

[paulr33]

I have the full RB26 DJETRO manual at home. I can scan it for you paul.

basically the map sensor nipples are inserted into cylinders 3 and 4 of the throttle bridge for the 26. then their loom runs to the side port on the PFC, and also splices into the ecu harness (I assume into the two AFM signal wires).

I don't know how much better or worse PFC DJETRO is than the LJETRO. like paul said once you are at target boost the maps output just hold a flat line even though the acutal volume of air going in will increase. so I guess more reliance is placed on RPM axis and maybe TPS etc.

hey if you can scan that manual that would be great. ive seen where it taps into the boost control port, i suspect this is for power source for the map sensors.

so the map sensor connect to the AFM inputs on the loom, that makes sense. ive had a look and even discussion on the datalogit forums its still a 2d map so its purely load and rpm so TPS is used to move the load axis around.

[Cubes]

Don't forget the inlet air temp sensors Mafia.. A critical part of a MAP based ECU if you want it to run half decently.

Im still under the impression load is derived purely from air temp and values received from the map sensors.

TPS.. I can't see it being useful for determining load especially on a forced induction motor.

[paulr33]

the datalogit guys disected the load axis calc and it just uses map sensor pimv instead of the afm volt and the same style CONST number calc

[WogsRus]

I know somone has propably said this somwher along the line, but there is a new PFC for R33 due out for release late december early to mid feb 2008.

My source, a good mate in Japan who works in the industry.

Apparantly all the models using the old NEC chip have been changed to use a new LG manufactured chip.

[The Mafia]

Any one have a djetro base map I can check out via the datalogit?

The afm pfc averages the two afm values and then derives the load value via a 32k constant. The single afm pfc's simply use a single afm value to derive load via a 16k constant.

I assume the djetro rb26 pfc runs to map sensors due to the rb26's individual throttle body's for each port. On the rb25 no doubt a single map bridged would do the trick. But why bother.. Just buy the kit.

Mafia.. Very keen to see the rb20 and rb30 back to back. The hks3037ProS would = poo on the rb20 unless you run the .6 scroll.

Yeah, you're right, they need two map sensors to average between the inlet runners. I forgot they'd need to put them there because of the multi throttle body design.

Surely I can just plumb both map sensors into the RB25 intake plenum and have no problems?

Regarding the HKs 30307 - His has the 0.63 HKS rear on it, and its clearly smaller than my rear. Not sure why, but interesting. Laggy as dog shit in the RB20 though, especially with the RB20 stock ECU untuned..

Don't forget the inlet air temp sensors Mafia.. A critical part of a MAP based ECU if you want it to run half decently.

Im still under the impression load is derived purely from air temp and values received from the map sensors.

TPS.. I can't see it being useful for determining load especially on a forced induction motor.

Also, I hadn't forgot about the temp sensor, as map sensors require this data heavily. Weird how the powerfc uses this data though? As they are just sending a signal into the AFM wires.? Might have to investigate this a little more. Still curious to know why it also needs to be hooked up to the Cylinder 3 and 4 wires. Sounds like a ghetto way of using map sensors.

the datalogit guys disected the load axis calc and it just uses map sensor pimv instead of the afm volt and the same style CONST number calc

Can you speak engrish?

I know somone has propably said this somwher along the line, but there is a new PFC for R33 due out for release late december early to mid feb 2008.

My source, a good mate in Japan who works in the industry.

Apparantly all the models using the old NEC chip have been changed to use a new LG manufactured chip.

Will they have a few extra features like Ignition cut and Launch control?

That would be great

[Beer Baron]

Also, I hadn't forgot about the temp sensor, as map sensors require this data heavily. Weird how the powerfc uses this data though? As they are just sending a signal into the AFM wires.? Might have to investigate this a little more. Still curious to know why it also needs to be hooked up to the Cylinder 3 and 4 wires.

they don't tap into the cylinder 3 and 4 wires. I don't know where you are getting that from. there is no such thing as cylinder 3 and 4 AFM wires. there are only two AFMS in a stock GTR. AFM1 and AFM2. the Map sensors are spliced into AFM1 and AFM2 ecu inputs.

and yes you should be fine to place the sensors elsewhere in your GTST but I'm sure there will need to be a little thought about where is the best placement in order to get a good result.

other than that it should be fine.

[WogsRus]

Hay my egrish wrocks. LOL.

Sorry i am a terrible speller, person thing.

LOL

Not sure about additional features, but i know that the other boards are looking at an upgrade to the new chips as well, but i can do a little more digging through my friend for you.

[The Mafia]

they don't tap into the cylinder 3 and 4 wires. I don't know where you are getting that from. there is no such thing as cylinder 3 and 4 AFM wires. there are only two AFMS in a stock GTR. AFM1 and AFM2. the Map sensors are spliced into AFM1 and AFM2 ecu inputs.

ahh pual said something a few posts back, but I see what you mean now. Maybe I misread?

Ok, one more question - Does the Cefiro have a different wiring loom than the RB20? Or is it exactly the same, and our new wiring scheme will work? Doing one for a mate.