First off, I know this subject is talked about OFTEN. I've read countless threads on the matter it can get a bit overwhelming. I finally bit the bullet, offloaded all my fb's and purchased a beautiful fd rx7 (my dream car). It's a 1996 japan import.
I want to start turning the car up a little. I plan on running stock turbos for a while, but id like to pick up a new intercooler setup (possibly v mount), and a high flow cat. It currently has an n1 exhaust which i plan on swapping out for a re twin dolphin tail. I have a small oil leak from the turbo area, so plan on pulling those to reseal and porting the wastegates at the same time.
From the many threads I've read, it seems like engine management is 100% necessary as a first step. I've been going back and fourth and was a bit confused on how the power fc works. When it runs the base map, does it just keep the AFR managed, or is the fuel on a boost table? Will I need custom tuning for those mods, or will a base map pretty much cover me? Will it also cover me if I eventually decide to go single turbo? Seems like finding tuners for the power fc is a challenge. Should I just bite the bullet and go haltech? Some other engine management?
Any leads on tuners in Arizona you'd trust? Thanks in advance. This forum has been unbelievably helpful. I've probably logged 100 hours of forum time learning about my car.

 

the Power FC just has a Boost vs Rpm table for fuel. for tuning a Power FC, check out FC Tweak, it really makes the Power FC tune itself
https://www.rx7club.com/3rd-generati...esome-1161545/

the Power FC can do single turbos too.

 

Even though PowerFC is popular and the FC-Tweak tool is very helpful for tuning the fuel map, the ECU strategy still lacks a few important engine failsafes and the datalogging is not as good as I would want for my car. A PowerFC will happily let the engine keep running at max power when the coolant is too hot, boost is higher than your fuel system can support, and the wideband O2 sensor is showing dangerously lean readings. Worse yet, without an extra interface box connected to a laptop, you won't have any datalogs to show what happened and will be stuck wondering why it doesn't idle well anymore.

I've heard mostly good things about Link engine management, and Haltech is popular but I dislike their datalog viewing software. For my car, my minimum requirements would be good datalogging and log viewing software (PowerFC can't log without the laptop connected, which is not acceptable to me) , realtime wideband O2 feedback (PowerFC doesn't have this), engine protection that can stop the engine from hurting itself in case of overboost, lean AFR, or dangerous coolant temperature (PowerFC doesn't have that either). I think it's also important to support a fuel pressure sensor input , oil pressure input, and oil temperature input. Bonus points if the ECU can protect the engine if any of those signals approach dangerous values. In Arizona, I would get in touch with UMS Tuning in Mesa, AZ.

 

the PFC does have protections for temps. it also has an over-boost fuel cut too, although its not the most obvious thing

the other things you point out, EGT, fuel pressure, etc are stuff you do want when power goes up, and the PFC can't really do it, which is when you'd want to look at something else.

 

I appreciate the info! The fc tweak seems like a really nice feature!

 

I think this is more what I needed to hear. With ambient temps well into the 110s, our weather is super hard on our vehicles. I reached out to UMS after researching them a bit and decided to ask them what they would recommend. I'd like to catalog and view data, but I'd really prefer to have all the tuning done by a professional. Since they'd be tuning it, I'll let them decide what platform I should use. The lack of failsafes on the PFC has me a little apprehensive. Thanks for the input!

 

a good ecu tuned really well is going to be better than a great ecu tuned badly

 

You’re better off upgrading to a Haltech. Haltech 1500 elite with plug and play wiring harness may be twice as much as the power fc route but you get soooo much more from it. Tunedbyshawn can hook you up with everything. ECU, wiring, wiring support/ trouble shooting and he’s a very well established remote tuner. You just have to plug it in and set up a meeting with him. Makes your knock sensors useless with all the other ways safeties can be implemented also offers many tuning and monitoring possibilities

 

I'm definitely going haltech. The tuner I plan on using recommended it. He uses the fc, but says the haltech just gives him a lot more control, and better limits.

 

The power FC was an absolute game changer when it came out. It is a good ECU but it is ANCIENT (26 yrs?) technology wise and so there are far superior ECUs out there that will do everything the power FC does and much more. But enough people have spoken about that. I actually came here to address the stuff that others aren't responding to.


Nope. Not in my book that is unless you are tuning the ECU as you progress in mods. The first step is to get a boost gauge/boost controller because the name of this game is Air/Fuel ratio. And other than swapping turbo(s), nothing changes the AFR as much as a change in boost levels. And with higher boost levels you will need more fuel to keep a safe AFR and this is where a tuned ECU comes into play.

Regarding the Power FC: Yes you need a custom tune as the base map was only really meant to be a great starting point to begin tuning. The base map runs rich enough to run a car at stock boost levels but also at the same time the stock ECU also runs rich enough for that. In other words, you aren't getting a benefit from the Power FC if you stick to the base map.

This is why I really came here. and the answer is:
NO TO THE HELL NO and that applies to any ECU that you are running. Tuned or not. Changing out the stock turbos for a single massively changes the AFR thus making your tune completely obsolete.

When it comes to turbos it is the CFM (Cubic feet per Meter) that matters. That is the rate the turbo (or turbos) are pushing air into the intake manifold. To help you understand, instead of turbos think of water pumps. Where a small pump (stock turbos) flows a certain amount of water (CFM) into a bucket at given pressure (in our case 10 psi for stock turbos). Now if you up the speed of the pump, the CFM will increase and so will the pressure. Makes sense right? More water flowing through the same pump = more pressure. In other words, you're upping the boost level.

Now swap the small water pump for a larger more powerful one and of course it is going to flow more water into the bucket. This is the important part: The larger pump will flow more water at the same pressure of the smaller one. I mean, it has to otherwise we would not be using the larger pump right?

Take note: We don't use flowmeters (they read CFM) we use boost sensors instead. Since a boost sensor simply provides an indication of flow and not directly reads it, we really only use 10psi as a reference point for stock turbos. Because we know our cars are factory tuned for whatever CFM is at 10 psi with the stock turbos. Naturally anything higher than 10psi indicates that the CFM is also higher; and with a higher CFM brings a change to the AFR. And this is where custom tuning comes into effect where we add fuel for the increase in CFM due to the higher pressure.

Technically speaking, when swapping out to a larger single turbo, that stock 10 psi reference along with the tune become completely useless. Because as you know given the same pressure, the CFM from the larger turbo is not the same as the same as the one from the stock turbos. In other words, when it comes to CFM 10psi from the stock units is not the same as 10 psi from a single and therefore you will need a retune to keep a safe AFR.

In my opinion, the first order of business is to control and monitor boost in order to always maintain 10psi as you add bolt-on mods (bolt-ons meaning excluding upgrades such as turbo/fuel pump/injectors/map sensor). What I mean by controlling boost is exactly that, controlling boost to the desired level by whatever means necessary (an electronic or manual boost controller and porting of the wastegate). However, if you want to be completely safe you can also throw in a wideband AFR to truly know if you are safe as you go along.