dguy

iTrader: (8)

Yeah I don't have any experience with a 16 bit ECU. I'm sure they fixed most of the issues.

Valkyrie

Using overshoot in order to cut down on turbo lag seems like really bad engineering.

SA3R

Well I tend to agree with Arghx- my car has a bone stock engine, with stock ECU. No real power adders. I have an aftermarket rear muffler under the rear bumper, and a revised oil PCV system with catch can and also a cold air intake that feeds cold air to the airbox and the intercooler has its own cold air scoop separately (like the 99-2000 cars)

My boost pattern has always been 10-8-10 then holding 8 (from memory) to redline. Boost comes on at 2800rpm. Stock twins.

A few times I have noted that the car at wide open throttle, highway, 2nd gear will show what I think is 11psi right before the secondary dip. My boost gauge is on the pillar and slightly angled, so its possible the needle peaked 12 but because of my viewing angle and the fact that 2nd gear in an automatic car runs out to 168kmh (insta-jail / loss of licence speed if you're caught doing that here in Australia on a public road) I'm not 100% if its 11 or 12psi its actually just touching at the transition point with the secondary coming online.

I also know that if I lock the transmission into 1st gear and just put my foot all the way down, both turbos are actually online and the turbo control valve is opening at around 3000rpm and it is NOT following the 10-8-10 pattern in first gear. This is verified with a gopro looking at the flapper valve which in 1st gear is just open and allowing both turbos to feed into near instantaneously, at the same time.
My logic was the same- 1st is short and engine speed rises so rapidly, there's no time for the 10-8-10 pattern to happen as the solenoids and lag time of the system is too slow. So she just opens the valve and its all-in boost during 1st, possibly only controlled by wastegate operation.
"non-sequential 1st gear".

The system is old, but it is more complex in its logic than many people want to believe. Whoever the hell came up with the programming, orifice sizing, logic.. That guy or group of guys were inhumanely bright for their time.

ninesixtwo

iTrader: (9)

ECU reflashes and PFC in Japan have gone further on rotary platform than anyone on this forum. The issues lie elsewhere. My turn to await the hate

dguy

iTrader: (8)

Do that with a PFC or reflash.

BLUE TII

iTrader: (9)

I'm not endorsing it or saying it was the right way, but the Japanese are so PFC crazy they actually did make a 4 rotor and run it off of two PFCs waaay waaay back.

I couldn't find a pic of the car when it was done in a quick yahoo.co.jp search (it was), but here you go for giggles.

ninesixtwo

iTrader: (9)

^^ Not sure what that abomination is

Done over a decade ago on Scoot's slide throttle car. Car still runs and is actually the only 4 rotor FD I've been in. This may be the 2 PFC car Blue TII is thinking of. EST Fukuyama also had a 3x PFC cosmo track 20B.


A little more relatable to the average FD owner though... How many 600+ WHP pump gas 2 rotor cars do you know of?

Valkyrie

Dafuk?

I assume it's naturally aspirated because that would be a plumbing and tuning nightmare if it was turbocharged.

BLUE TII

iTrader: (9)

I was hoping it was turbo and side port because that is the only reason I can see to keep the stock intake manifolds.

This one is obviously turbo.


Not seeing a plumbing issue.

Valkyrie

That car is going to have....issues....with cooling.

I am surprised they managed fit all that piping in there.

I wonder if they're using a 20B intermediate plate. Would the eccentric shaft need to be three-piece?

dguy

iTrader: (8)

Jesus. I applaud the fact that they could jimmy something together to run their 4 rotors out of some hamstrung tech but come on guys :P

The PFC has 3 ignition outs and 4 injector drivers. If you want to start throwing multiple boxes at a situation all the while comparing it to a single PFC or reflash I'm going to have to start calling every other ECU in the world a piece cause I could technically get a laptop and infinity Labjacks and write some half baked Matlab code to run a car and be infinitely expandable. Be reasonable.

ninesixtwo

iTrader: (9)

Second set of crank triggers mounted 180 degrees apart from the original ones makes it relatively simple to run a flat-plane 4 rotor on 2x PFCs It works, and it works well. There's nothing ghetto about the Scoot FD by any measure.

What's unreasonable? I don't think I said that the PFC is superior tech, merely that it isn't the root of the FD's reputation for being fragile and temperamental. Seen too many reliable big power circuit cars running PFC or Vpro (or both) for me to believe that. If your tune is off, engine is soft, turbo is mismatched, fuel supply is bad (mechanically or otherwise), charge temps too high or any other similar malady, the longest feature list in the world won't help you forever.

FWIW the EST Fukuyama car ditched the PFCs for an M800 iirc

dguy

iTrader: (8)

If it can't be understood that throwing 2 boxes at a problem to find a solution that carries zero failsafe or communication between the two units then I think the conversation is kind of a non starter.

ninesixtwo

iTrader: (9)

Get some sleep and try again when you can form a complete thought

dguy

iTrader: (8)

Oh. So you're just trying to be a toolbag and aren't really interested in conversing on the validity of my 'Old ECUs and locked down reflashes/black boxes gave the FD a bad name' comment. Ok.

ninesixtwo

iTrader: (9)

Grow up. You're the one that's now twice declared the discussion over and thrown insults after I showed a video of PFC running a 4 rotor as you challenged. You haven't made a single counterpoint, and in fact your last comment was utterly nonsensical.

dguy

iTrader: (8)

Actually it'd be a barbed response after a patronizing comment. If you want to get holier than thou at least hold yourself up to the same standards.

With regards to counterpoints RE a PFC running Defined's 4 rotor and using a PFC (or a reflash, lets not forget this comment is what put a bee in your bonnet) I give you this example:

You're given the car complete with everything you could shake a stick at, wiring, your dual triggers if needed, et cetera EXCEPT the ecu. You then have a choice between 2 cardboard boxes. One box contains a singular M800 (or really any other 6+ ignition out 8 injector driver ecu). The other box contains a singular PFC. All you need to do is make the car go. Which one would be able to control such a beast?

It's almost like you're taking it personally that I think that the equipment some Japanese dudes back in the 90s is archaic. If you have a car that runs with the PFC well, cool. If you've seen some very well respected and knowledgable tuning houses make badass circuit cars, cool. It doesn't change the fact that the ECU is lacking in an insane amount of feature sets and safety schemes that would most likely have saved many hack-job tuners or would have allowed the badasses to make even greater cars. Their migration to an M800 as an perfect example.

You don't see me getting my panties in a twist because someone says that my 13b is technologically inferior to an EcoBoost.

arghx

iTrader: (3)

I deal with engine controls in my day job, as I am basically an OEM tuner. I think it's important we understand the difference between a controller and the controls.

The controller is the box with wires connected to it. It's the injector drivers, analog inputs and outputs, signal processing, etc.

The controls are the instructions inside the software. It's the "when this happens, do that." That sounds obvious, but the distinction is important.

Clearly, the Mazda 8 bit and 16 bit stock ECUs are inferior to any stock ECU today in terms of the controller, and certainly inferior to the top of the line aftermarket ECUs available today. The box itself, which connects to all the wires and such, it's not good. The PFC itself is old in terms of the box, in terms of the controls. It has a lot of inputs and outputs to drive all the stock signals.

So the Power FC as a controller is outdated, but it has all the inputs and outputs to control all the stock hardware on an FD (emission solenoids for example, A/C clutch control, etc). But it can't for example control an electronic throttle, or a direct injection pump, or an electronic wastegate.


However, the control strategies of the stock ECU as we've established are very sophisticated in certain areas. We know it has gear based logic for boost control and sequential turbo control, which is impressive for the late 80s/early 90s. It has different modes to control all the emissions equipment and injector staging. The Power FC, too, has logic to control the stock emissions equipment and sequential system, although it may not be able to control it as well as stock.

If you buy a higher end racing controller like an AEM Infinity, it has a lot of inputs and outputs, a much superior processor, can control electronic throttle, etc. But it doesn't come out of the box with a bunch of maps and logic to control the sequential turbos in a gear-based manner, or to switch on and off the air pump solenoids according to engine temperature. So for the application, some of the AEM or Motec or whatever just isn't as good of controls.

You can have really good instructions inside the ECU for the application (stock ECU) but a really crappy controller as a box with a processor (stock ECU). You can have a bunch of general maps and tables and sophisticated logic, but it's universal/not specific to the application, packaged with a high end controller box, like a Motec or an AEM Infinity.

ninesixtwo

iTrader: (9)

You said:

"If it can't be understood that throwing 2 boxes at a problem to find a solution that carries zero failsafe or communication between the two units"

If what exactly can't be understood? Makes no sense.



That car was built in 2001 or 2002. The M800 was not in the picture, M8 would have been the other consideration. It's just as antiquated and would have also required expansion boxes. Would it be nice to have all management in one box? Sure, but running dual ECUs has been done by OEs. Sometimes it's an appropriate solution.

I'm not taking anything personally, none of the cars I have in mind are my own. I don't even run a PFC - I switched to ProEFI and a MoTeC PDM. Your own statement reflects exactly what I am trying to say:

"It doesn't change the fact that the ECU is lacking in an insane amount of feature sets and safety schemes that would most likely have saved many hack-job tuners"

PFC on a poorly set up or poorly tuned car won't last, but if you have the same clown install and set up an F88 it won't make a difference in the long run. However, a PFC on a well set up and well tuned car can be very reliable. Which brings me back full circle to your original statement that the PFC is responsible for much of the FDs negative reputation. Do you have any specific issues or experience where a PFC has been solely responsible for an engine popping? Please share if so, I've been genuinely waiting for you to offer this information up instead of insults.

Ecoboost? lol. I'm painfully aware of the advances in control strategies and combustion chamber optimization that OEs have made since the advent of DI. That's neither here nor there, it's just another dodge in an attempt to paint me as some butthurt fanboy.

j9fd3s

iTrader: (3)

it is, that car was built in 2001 and is still running.

if you want other examples, Racing Beat went 238mph a bonneville with mechanical injection and a distributor, and Mercedes was making 600 hp in the mid 1930's with carburetors...