Hi guys,

left my car for the last 3-4 years whilst on with other projects but getting back to it (car was drained of fluids etc).

Currently have an Apexi but have seen more modern ecus provide better protection / features etc.

Therefore a quick question, do modern ecus make the RX7 more reliable with the built in protection etc?

I guess by reliable I mean less likely to go bang if something fails ?

Apologies if in the wrong place but more interested in FD view rather than FB / FC. Considering whether to stick with Apexi or look for something different (I have a stock port, single turbo).

Thanks

 

in theory yes, the protections should help, but if you map the Power FC correctly you can get it to do some of it.

having a cut for overboost seems to be the really important one, and the PFC has that, we see threads about that once in a while, not so much for the other stuff

 

You're going to find that geographically speaking, PowerFC tuners are limited. Most people don't want to mess with it anymore as it's significantly more involved when tuning than a modern ECU. The technology is now 30 years old, PowerFC drivers fail commonly. Newer ECU's have tons of inputs that gather more data, more accurately and can provide higher resolution. So I'd argue they can be used to make more reliable power. That said, it's plug and play, the base map is ok for basic mods, and if that's the way you intend to enjoy the car, there's nothing wrong with a powerFC. Tons of cars are running out there on PowerFC's and have been for years. I think Xaviers FC-Tweak software is really making huge gains in ease of use for the PowerFC and people who want to tune their own cars. The PowerFC mailing list is a HUGE trove of information if you want to stick with it. I'm on there and even if you don't own a powerFC it's got a lot of good info.

Another benefit of the newer ECU's is remote tuning for startup, street and dyno. Where if you have a wifi or hotspot connection you can drive/make pulls while you're tuner is watching the logs and making updates to the ECU. That's probably the biggest deal for me as no one around where I live tunes them, and the ones that are within about 700 miles have time to do it. I think some of the lack of schedule availability boils down to the shop just not wanting to deal with a powerFC. If you called them up and told them you had their ECU of choice and it takes less time to tune, they'd probably fit you right in. Some shops have told me it takes 6+ hours to tune a powerFC accurately the way they tune, where as a microtech adaptronic or haltech could be in and out in an hour assuming no surprises.

Just my experience. YMMV and everyone has their take on it too.

 

The big thing that's really changed in the past 20 years or so is getting a better understanding of tuning. Really an RX-7 engine can be tuned to be VERY reliable with good power at this point.

The PowerFC is tried, tested, and works awesome for cars that have stock twins. If you're going single turbo, going with a different ECU may be a good idea, especially if you are chasing big numbers. But, the PowerFC really has near-OEM reliability all things considered. I've seen a number of people stranded with aftermarket ECU's - "oh, I need to re-flash it", "it didn't like the crank pickup" - little things like that. My PFC hasn't let me down in the 15 or so years it's been on my car.

Newer ECU's like the Haltech can do some cool engine protection strategies. They also need to be set up and implemented properly. Also, if the tune isn't good, you can still cause engine damage - still a case of garbage in, garbage out.

Really we are in a golden age as far as engine reliability is concerned. Better apex seals, better understanding of tuning, cheap wide bands - this all contributes to cars going for a VERY long time.

All that said, a twin turbo car or single turbo around 400hp I would probably go PFC. Going for big power/big single, go Haltech. If you want to really monkey with the tune and settings and get your hands dirty on the ECU the Haltech may be a better option.

Dale

 

It depends where you are starting from. From a full single turbo build, you have a lot more capabilities with a newer ECU. All the additional features do take time to get working. Tuners charge by the hour or they give you some kind of package deal which assumes some number of hours. They're not going to be able to implement everything unless you pay them a lot of money, or you accept less customization, or they just lose money on the job. Some of the "quality of life" features of the newer ECU's, such as electronic throttle control, full time closed loop wideband, maybe traction control, etc require the tuner to have experience and understanding of that feature.

If you have enough personal tuning know-how to implement the newer ECU's, or you have a tuner who knows the ECU and knows rotaries, then it's a benefit. If you buy the ECU and the tuner is unfamiliar with rotaries, or you attempt to tune it yourself and get in over your head, it's not an advantage. A well tuned Power FC will do better than the latest AEM, Haltech, that is not tuned well.

For the most mildly modified cars (1 or 2 mods maybe) I've argued in the past that the stock ECU is the most reliable due to being designed for a broad range of driving conditions (altitude and weather changes, poor fuel quality, etc). The hesitation issue that can be found on some stock ECU FD's is a downside, although my '95 had it show up only rarely.

However no matter what ECU you have, old car stuff is going to come up. The body electrical systems degrade, the interior degrades, all the rubber on the car degrades, etc.

 

I've never had a Power FC, but I've had three generations of AEM ECUs on my car. The most modern generation is a little easier to tune, but IMHO the main advantages for our cars are better datalogging and has more protections. More protections includes rev limiters if oil or coolant is too hot (or too cold), rev limiter if O2 is too lean, or if boost is too high, or if oil pressure is too low. Boost control is more flexible so you can avoid overboosting in the first place by decreasing the base duty cycle in 4th/5th gear, or when air temp is cold, similar to what modern OEM computers are doing. Previous generations already had the ability to do cool things like boost-by-gear or boost-by-ethanol-content, the latest generation can also modify the boost target if the measured fuel pressure goes lower than it should (taking fuel pressure vs boost pressure into account).

I think it's also important that the datalogging is so much better in the recent generations. You can save a lot of data for yourself to review, or email it to a tuner who is familiar with the system and they're less likely to complain that your log is missing that one channel they wanted to see. When I have the laptop connected, I'm logging over 150 channels at over 20 samples per second which is plenty fast for most things you want to do. When the laptop isn't connected, the ECU is logging 35 channels to a USB flash drive any time the engine is running.

I'm a member of the Power FC Tuning email list and I agree the recent tuning software looks great. If you've already got a Power FC and the car runs well, you could probably spend a new ECU's worth of money on replacing other old parts (fuel pump, filter, injectors, coils). If you're the kind of person who would enjoy geeking out on data logs, a newer system might be the way to go and you might be able to sell your Power FC while people are still buying them. If you're interested in learning about tuning to do it yourself, HP Academy has a lot of good video lessons available at reasonable prices.