Apexi Powerfc, Rb25det (r33), And Jatco 4n71b?

[b1ancardi]

Just wondering, I heard that PowerFCs do not work with autos?

I have an RB25det, with the original VL automatic transmission, the Jatco 4N71B.

Apart from strength issues of the gearbox, will I have troubles using a powerFC?

Its just that I can get one very cheap right now!!

[STATUS]

  b1ancardi said:

Just wondering, I heard that PowerFCs do not work with autos?

I have an RB25det, with the original VL automatic transmission, the Jatco 4N71B.

Apart from strength issues of the gearbox, will I have troubles using a powerFC?

Its just that I can get one very cheap right now!!

Ive done a few R33's with autos and power fc's and it works but the shift quality is reduced as is kick down sensitivity, if it is a full built box then it wont be much of an issue. The other option is to fit a 300zx ecu and nistune it which gives factory like changes.

[b1ancardi]

Just another thing to add, the 4N71B doesnt have its own ECU like the proper R33 auto boxes have.

I dont know much about gearboxes at all, but apparantly PFCs will work fine with 'mechanically' controlled autos, unlike electronically controlled ones ..... would the 4N71B be mechanically controlled? I dont even know what that means.

http://www.paulr33.com/powerfc-faq/powerfc-faq.htm#6

[b1ancardi]

okay, well apparently my ecu is a manual one anyway, and the gearbox is fine with that, so I assume an aftermarket ecu which totally replaces a manual ecu, should just keep my auto working the way it is now

[paulr33]

yeah from memory the VL jatco box is fine as it has it's own auto ecu vs the skyline auto box that relies on the normal ECU to do the work for it

i dont understand why, but i think the jatco is ok and it shouldnt flare as its own ECU tells the autobox what to do

i suspect the jatco and it's ECU has its own mapping for gear up/down logic and watches RPM, TPS etc

so it can work out when to change gear and disengages itself so it doesnt flare, and then re-enages

vs the R33 auto box

where it relies on the ECU to back out timing during gear change

ie the auto box can do the mapping for speed/RPM/TpS gear change OK, but it expects the ECU to back out timing, and it wont disengage itself

does my theory sound right?

[b1ancardi]

I just scored this for $1500

whoop whoop!

[James_03]

Yeah the r31 S3 had the first gen square pan electronic boxes with controller under the passenger seat. All vl's are mechanical.

Should be fine.

Edited May 19, 2010 by James_03

[b1ancardi]

Excellent

[b1ancardi]

Picked up my Power FC today.

It used, and already tuned to the previous car.

Does anyone know if its okay to connect to my car, just to see if its working or not? Or should I not do that?

[paulr33]

read the PFC FAQ as per my sig

plug it in, turn car to ON, but DONT start the car

then do DATA INIT as per powerfc FAQ and self idle learn procedure

be sure to read the documentation and on how to self install, set injectors (if non std), airflow meter (if non std), boost kit BEFORE starting the car

[b1ancardi]

Will I cause myself dramas if I connect the Power FC up to the VL now, just to see if its working, and then reconnect my normal ecu after?

Never played around with this kind of stuff is all.

[boostn0199]

You can hook it up and turn on the ignition and see if it turns on the hand controller and all that but unless you are suer of the afm , injector settings and all that dont start it, If you want to start it as paul said take a look at hes faq and go through hes methods of idle learning adjusting the injectors and afm settings and all that then giv it a start to see if it works.

[b1ancardi]

hmmmm .... hand controller doesnt come on...

[paulr33]

check the basics, check wiring, check ECCS, check relays