Rotor #2 failures/misfires?
 

It seems to me that almost all of the misfire complaints are for rotor #2.
I also have noted that almost all of the failures on both the Renesis and the REW are in rotor #2.
This might be a cooling issue (the coolant has already passed by rotor #1 on its way to rotor#2) or an oiling issue (though the oil seems to go the other way AFAIK) that lead to a greater likelihood of detonation in rotor #2.
I don't think it is a fuel starvation issue since the fuel rails are center-fed and have no return, or a breathing issue since the intake manifold is pretty much symmetrical.
On the exhaust side, #2 is the closest to the end of the line, so the residual temps should be lower.

I've begun adding a few milliseconds to the injector pulse on just rotor #2. I'll see how much more rich I can go before it begins to adversely affect power. The added fuel might have a quenching effect.

Ideas?

No ideas...but it's common from time to time to see aftermarket companies advertising their intake manifolds to be engineered to even flow and temps between the front and rear rotor in and effort to stabilize number 2.

I've always wondered how much those are gimmicks, and how much good they really do...and as you state above, the Renesis intake manifold is "pretty much symmetrical".

edit: actually probably way far fetched and complicated - but I always wondered how difficult it would be to run a separate coolant line into the second rotor - basically a feed for each that could collect after the engine on the way back to the radiator - probably more trouble, complication and machining than it is worth for an experiment. And also because the cooling of the rotors is through oil in the eccentric shaft...maybe have more injection into the rear rotor through the eccentric shaft...I don't know just rambling and throwing stuff out there...

Bah...this is why we need each rotor/housing as a standalone unit that can "lego" to another one's eshaft...snap together for more power! haa haa

One can dream cant they...and no one said that dreams had to be well thought out...

would be interesting to monitor a/f and egt from each rotor --like recips do their banks. OD

You could do it, but the sensors wouldn't live very long.
Independent EGT probes would be more up to the task, but you would have to know what you are looking at for the data to be useful.

back when I had misfires it occured at various times on both, but that was a long time ago

Were your misfires tied to any particular engine fault or condition?
Remember, it is "normal" to have rotor misfires (as per Mazda).

I have yet to drive an '8 in which I can't trigger a #2 misfire. (Except the current motor in mine, but I haven't really tried as yet.)

Really ? .... hmm ...

I never have one ..... am I having a problem ? :Eyecrazy:

Let me drive your car. I can demonstrate.

You could,whenever you visit New york :)

Man if you guys come to New York, I'll show up to watch... and take pictures.

I had misfire codes while breaking in my engine the fast, hard way

that was two years ago and I've never had any since, can't recall any specifics other than it was during sustained high rpm operation, that's all since I can barely remember last week ...

Your doing better than me...I cant even remember my first name half the time...

I had the same issue, misfiring at rotor 2. The problem was resolved after replacing the MAF sensor.

I've only gotten my 8 to deotante once, and it was rotor #2.
This is interesting. My guess would that rotor 2 is hotter than rotor 1, especially since the coolant flows 1-2. It would be a neat idea to try to make a T in the coolant feed hose and flow it into the rotor #2 housing. But the coolant flows internally from one housing to the other right? So you would have to block up the internal passage that connects them and make a feed/return circut for each housing. Could get complicated. But if coolant doesn't flow internally between the housings (which I think it does) it would be extremely easy mainly because each housing already has their own feed and return connctions, so all you need is a T fitting.

substained high rpm with partial throttle then full thottle will do it.
OD

We need lego housings!!!

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yup -- ive gotten "cylinder 2 mifires" always at high RPM spurts. Seems most of mine happened when I'd cruise at 90-100mph on the highway.

I got in mine pobaly too. And I don't know why, my car is now much slower than not a long time ago.. Misfires can be cause of that??

what model and what year is your car?

the rear rotor does run a bit hotter, because its cooled last. if you do a bit of searching on rx7 club howard coleman (among a couple of others) have egt and wb data of the fd's. they run a little leaner in the rear due to the intake design.

leaner + hotter = boom

since its there by design, its a tuning limitation, and being aware of it, is step one

fixes of course would be running the rear rotor a tad richer for the cooling, colder oil, colder coolant, etc etc

EU version, 231 HP , model 2004.

Really .... I do alot of high rpm shifts still no cel (not even pending)

Yikes ...

Now Im wondering what my engine will be like, when I tear it apart at around 60K miles ... (now 29.5, 30.5K miles to go !)

I was curious if anyone would bite on that idea I threw out there...

The coolant does flow internally from one housing to the next. I have thought the same as you. Block off the water passage - specifically in the intermediate plate - and do like a 45 degree bend (something not as radical as 90 degrees) leading out of the intermediate plate. At the same time, lead another line into the same intermediate plate for the second housing. Then reconnect down stream after the engine.

Or less invasive would be to run an auxillary water line and tap into the intermediate plate and get some cooler water into the second housing. But whether or not that would work I'm not sure. You'd probably have to run some pressure and temp sensors throughout the coolant system to have a clue.

Very true on the OEM or a turbo header, but I'd think you could get away with independant WBO2 sensors on a NA aftermarket tubular header as it would just mean inserting the new bungs up a few inches from the normal location in the collector.

http://www.japanparts.com/images/Ima...base=1&no=1762

...if anyone wants to give me about $2k, i'd gladly research it :lol2: