inis

i know that i will lose my hold function with the PFC. does the power FC allow you to tell the car when to shift? Is there any way for me to control when the auto will shift?

weaklink

Sort of. I mostly leave the tranny in L when driving around town, and sometimes S when I get on the freeway. I only use D for long highway cruising. Basically L limits you to 1 and 2; S = 1, 2, and 3. I find that in L you pretty much are in 2nd all the time which can carry you to +\- 70mph with the rev limiter bumped to 8K. Perfect for around town driving. Still get kickdown to 1 when you floor it and when you shift manually to S there is only 3rd left so it holds that until you shift into D which happens for me around 130 or so.

inis

wait, i must be confused, what exactly does the hold button do? what am i losing by putting on a Power FC, and is here any way to compensate for this loss?

RX794

You can actually make the auto tranny work like stock with the PFC, BUT what you have to do is use BOTH the stock, and the PFC ecu's at the same time, basically from what I understand what controls the tranny has to be hooked up to the stock ECU, and whatever controls the motor gets hooked up to the PFC, I don' t know exactly how to do it, but a few people on the forum have mentioned and done this, you just have to search for it.

inis

as far as i was aware, the auto tranny had its separate ecu, im not sure if or how it plugs into the main ecu. if anyone has more info, please post, and i will also try to search.

weaklink

blah blah blah....yes the tranny has its own ecu. yes it connects to the main ecu via a second harness. yes you will lose the hold function with the PFC. the hold function will "hold" a selected gear or gears depending on where the lever is, similar to what I described above. Also, if you are in "D" the car will start in 2nd gear for traction when it's wet. The main harness plugs into the PFC just like the stock ECU. But wait! What's this? There is no place to plug in the trans ECU to the PFC. Egads, your tranny ECU is now "stranded". Good news, your transmission will continue to function, except that the shifts will be a bit rougher. The hold light will flash continuously and you will not have the hold function. Please consult your owner's manual for info on the hold function, please consult any of the online service manuals (www.iluvmyrx7.com) for tranny ecu, hookup, and a detailed description of what signals are sent between the tranny ecu and the main ecu. You could wire the PFC in parallel as described but what a pain in the ***! You'd be better off going with a piggyback rather than piggybacking a standalone. Yes, please search as this has been discussed ad nauseum. Hope this helps.

inis

i appreciate all the help. is it this roughness that will cause the tranny to blow quickly. i dont know what to think about boosting it more than stock. alot of people told me they blew it in the first day, others said they have never had a problem, and some said to keep it out of high speeds. any info on this?

weaklink

not likely. probably it is more a combination of the extra torque, hp, and heat beating up on the **** poor design of the tranny. Did you know that the tranny is the same as the one in the MPV minivan? The only truly safe method is abstinence. Leave the car stock except for reliability mods like AST, and downpipe. My tranny blew in a few hours. So far so good after a VERY expensive rebuild (keeping fingers crossed).

inis

if i keep stock boost levels, and dont run it hard will i be ok for a while, or should i just plan a rebuild or swap right now?

weaklink

someone once said, "if it ain't broke, don't fix it." What mods do you have? If you are close to stock then don't sweat it. If wouldn't hurt to swap to a synthetic ATF.

http://www.google.com/search?hl=en&i...=synthetic+atf

...enjoy!

inis

when its all put together i will have downpipe, midpipe, catback, intake, fmic, profec b, and pulleys. and then of course the power fc.

Rx7oneluv

From what I've been told more than 300hp to the stock Auto Tranny is the way to kill it quickly. I've kind of have the same questions as u Inis, I got a downpipe and exhaust and want to go to Intake, PFC, and Non-Seq Conversion w/Efini Y-pipe on my Auto. Boost is messed up and the car is having idle problems, stalling problems with AC on, and all that good stuff to make me pull my hair out. So I too am wondering if im safe to get the PFC just for correcting some of my problems and to help my mild Mods on my car (exhaust, downpipe, intake, and Non-Seq conversion). Am I safe with the PFC with just these Mods?

inis

i talked to rx-7.com today. obviously more hp will kill it. the tranny doesnt nessecarily shift harder, but it shifts alot different because of the way the power fc works. they told me that if you put it on, just be ready to swap or rebuild soon. it will happen.

weaklink

rx7oneluv-if your car is running poorly, don't think that installing a PFC is going to fix it. Your car should be in optimum shape before you start adding power.

inis-the car will shift harder since the engine is no longer receiving the torque reduction signal from the tranny ecu.

Rx7oneluv

Well my main plan is to simplify the car and have total control over how it performs. So I figured the PFC would help me with monitoring and controling the car, once I do the Non-seq conversion.

inis

that that torque reductioin signal caused it not to drop as much power during shifts, thereby putting more force into the tranny?