Raevik

I called Mazda corporate and discussed the information I'd read here.

Here's what I asked them:

Is it true that there was a last minute EPA regulation hitch that caused Mazda to reprogram the ECU to run richer, and thereby decrease horsepower and fuel economy?

Here was the response:

The variance in horsepower from the original 250 to the current 238 was simply the product of a technical miscommunication between the engineering department in Japan and local publications. There was no ECU reprogramming and the car functions entirely as intended.

This response came from a senior technical advisor at Mazda corporate who I was transferred to when I asked a technical question.

Interesting, isn't it?

rotarymagic

What a joke.

I wonder, did they translate the 238 in Japanese to the 250 in English miscorrectly?

Raevik

Not sure. When he told me that, there wasn't much I could say.

It's stated as fact on these boards, but when push came to shove, I really didn't have another source to draw on to argue with him.

Where did the story about this remapping of the ECM come from? Is it founded in anything other than forum-speak?

Haze

One of the early Mars probes that was sent to map the planet before the current probes arrived almost crashed because the an engineer made a mistake with his calcualtions between inches and Metric. Engineers do make mistakes and this could have been one.

Of course this is the THIRD thing that I have heard hi up Mazda technicians say as reported on this forum. I think that it is just spin doctoring.

93rdcurrent

If Mazda were to admit anything there would be instant grounds for all of us to jump on them for. MPG issue is huge. Don't expect any auto manufacturer to admit something that would cause them to loose money unless they couldn't possibly avoid it. Look at the Ford/Firestone recalls. How many vehicles did that problem happen to and no admition that they knew what was going on. There were lives at stake. We just have our poor wallets and the enviromental issues to consider. Mazda will either take their time or not admit anything ever. Unless we make a big enough issue out of it directly to them. Oops found myself on the soapbox again... sorry I'll shut up now...:o

zoom44

this is what they were saying ahwile ago:

zoom44

this is what they said in the letter:

zoom44

this is what they said in the letter

zoom44

and this is what dan from rotarynews.com told us after his talks with mazda:

Since thigs are out in the open now, I won't have to explain this to a thousand people at SevenStock. I guess we should have just play the 20 questions game from the start.

To reiterate: 3 know faults on the Dyno cause the car to go into Safe Mode. This is not a guess, it is a fact, and can be verified by someone with a code reader (how's that project coming along, anyhow?). You can also verify this by seeing the upper end of the dyno "spazz out" ... and look at the AF readings.

Now as to the why on the power reduction: Cat Core temp... By federal law, emmission equipment has to last for 100,000 miles. At the rotary's high exhaust temperature, the cat will destroy itself. (any previous RX-7 owner can tell you cheap cats will be destroyed by the rotary's hot-hot-hot exhaust in a matter of months... causing a neato flaming/shooting of little peices of converter material out the tail pipes... Happend on both my 1st gen (12a) and 2nd gen (13b) )

So there is hope: The engine is able to produce the orig promised HP, at the cost of cat longevity. Or, if anyone know a good chemical engineer with specialization in thermal calalistic reactions, have them see if there is anything they can recommed for a long-life, high-flow cat that can last under the extreme heat of a rotary's exhaust.

Haze

Yup, that would encompass the things that I've heard here.

Just out of curiosity, and I am SURE that this is a stupid question, but wouldn't mounting the catalytic converter further back in the Exhaust system alleviate the overheating issue in the cat? Sorry to be so dumb, there has to be some thermal loss in the exhaust temp from travelling through the exhaust. Please tell me why I am stupid.

Reeko

Not stupid.
This came up before. The CAT is mounted close, so that it meets the Cali emissions test which requires the cat heat up very quickly. (I don't know the details).
Basically, the Cali rules require the vehicle to meet emissions with in a couple of minutes from a cold start. This forces the automaker to move the cat furthur forward so that it reaches operating temps in the time required.

Haze

Thanks! That's interesting. I often forget the effect that California emissions standards can have on manufacturers.

MazdaManiac

iTrader: (3)

I think the most compelling argument for the reality of the PCM retune is the simple fact that the power can be recovered by simply getting the air-fuel ratios back into optimal range.
That is what Canzoomer's box does as well as my E-Manage installation.

There is no other more sensible explanation that I have seen for why the A/F ratios are so off the mark in a stock RX-8.

BTW - you do know what "llathos" means in Greek, right?

Baller

Together they dragged the rogue out of the street and between two small buildings. Llathos stretched her out flat and face up. He then knelt next to her shoulder and placed his hands gently on her cheeks. As he chanted to himself, he began to feel her life essence. He followed its pattern, the slow ebb and flow of her breathing, the light thumping of her heart. Her spirit was at once at piece and violently disturbed.

He began to probe through her with his mind. The problem was in her head. She had been hit hard and her skull seemed to be dented where something had run into her. First, he concentrated on pushing the dent back out. Gently, gently, he didn't want to do too much too fast. If he wasn't perfect in his maneuvers, he would kill her faster than she would have died normally.

MazdaManiac

iTrader: (3)

"Llathos" means "wrong" or "incorrect" in Greek.

I don't know what all that romance novel stuff is all about.

93rdcurrent

It sounds like Anne Rice to me. Could be wrong but then I have read so many of her novels that I could have seen that passage and not even remember. Oh well...

Nubo

Can someone explain why exhaust from a rotary engine would be any hotter than a piston engine's? Air + Gasoline. From where comes the extra heat?

ChrisW

It is clear that the ECU is limiting the engine output at high revs (very rich mixture) and the explanation about catalyst temperature seems completely plausible. The question is, at what point did Mazda know about this problem and do the change to the ECU?

Mazda are saying it wasn't a last minute change. OK, there were prototypes that had different ECU's, but this is reasonable, as prototypes don't have to pass emissions. There wasn't a "remapping" as the US cars were never going to get the prototype's ECU anyway. I believe the ECU was finalized in plenty of time for first US production, because Mazda will have known about US emissions reqirements for a long time and they have also known about the catalyst longevity problems for a long time (someone posted a link to a paper they published on this phenomenon that dated from 2001).

So how did Mazda get the horsepower wrong? I don't believe for a moment that it was a just a typo, but surely we have to allow them their face-saving story here? It's history now and they did compensate people.

guy321

I believe it's from increased friction. There's more surface area between moving parts in the rotary engine than in the piston engine. So it takes more kenetic energy to burn fuel, hence more heat (and poor mileage, compared to displacement in piston engines).

jdaled

More friction would cause more heat in the rotor housings, but not necessarily the exhaust. A normal piston engine in a car only has one combustion per two "rise and fall" cycles fo the piston, (one for combustion, one for exhaust)... it's more complicated than than, but that's the nutshell version. However, in a rotary, there are three combustions per rotation, and at the same time as each combustion is happening on one side of the rotor, the exhaust is being pushed out from the next side, and fuel/air is being brought in on the third side. So, constant fire with no downtime in between means more heat.

Well, there's my take on it anyways.

Sea Ray

Does anyone know exactly what the port campaign involved? I had assumed it was the reflash for the first few shippments to get the new pgm. I have also heard that this is where the options such as apperance pkg, spoiler, spare, etc, are installed? Do the very newest vin #'s still have a port campaign sticker under the hood?

shebam

Never noticed it on mine (delivered 7/21). Where?

Sea Ray

Under the front right side. Mine was brought in about the same time although I bought it first of Dec. I may take a pic of it and post it, but that will be Sunday after a trip to the sunshine state

ggreen29

My take is that in a piston engine, after exhaust the piston draws in relatively cool air during intake, which cools everything slightly. Then there's compression, which allows another slight heat rest relative to ignition & exhaust.

With a rotor, intake always occurs in the same part of the engine, compression & ignition always occur in another part of the engine, and exhaust is always occuring in the final third (so to speak) of the engine. There's no rest for that portion of the engine.

ChrisW

I remember reading the threads about this at the time, and it seemed that the only port campaign sticker that was common to all cars was the one related to the dipstick - the wrong ones were originally fitted and these had to be replaced in the port. If the ECU was reflashed in port (and I don't think we've any reason to believe that it was) there was no sticker for it.