2012 Mazda RX-9 ???

[old greg]

Originally Posted by Dimman

5k with a good muffler would probably be fine.

Not to mention that if you're only going to run it at a single RPM, you can tune the engine mounts and muffler/resonator specifically for the frequencies produced at that particular rpm.

A rotary would package really well with a YASA-style generator mounted directly to the eccentric shaft and end plate. I want to do it myself, just to bask in the awesomeness.

[NastyNate]

Give me rx7 styling and go with piston ease of maintence and Im in. Othan a turbo'd e46 m3 an rx7 is one of the few cars I would ditch my miata for. And even then it would be a very tough call

[Dimman]

Picked up a book on 2-stroke tuning to see how much more advanced they were in their exhaust tuning. Then I realized they are practically at full overlap for their whole events. D'oh. Is interesting to see how much of a change pulse tuning can make on them, though.

Buuuuut... I found out that some use a power valve that basically alters the height or shape of their ports. Since a rotary is essentially a 2-stroke except with a fairy-pushed couple of triangles rather than natural and godly pistons, I figured why don't they use something like this, too?

If they used one on either side (or top/bottom, whatever...) of their ports they could effectively change their advance and retard like cam phasers, AND have control over duration. However this looks more likely to apply to a peripheral port setup, and the Renesis is side ported (? in the end-piece separating parts, not the barrels) for emissions, I believe?

But if it was an overlap thing for emissions, and if they can control it they can go back to the more flow-friendly peripheral porting maybe? But maybe peripheral porting is worse for apex sealing?

Any reason this isn't used? Or maybe it has been used in the past? Reliability and complexity are the first strikes against it, off the top of my head...

[old greg]

Originally Posted by Dimman

Reliability and complexity are the first strikes against it, off the top of my head...

As opposed to laser spark plugs?

Actually, I would think it would be harder to do properly with a peripheral port because of the curved surface and the water jacket. Interestingly though, I've heard that N/A rotaries respond quite well to headers with expansion chambers.

[Dimman]

Originally Posted by old greg

As opposed to laser spark plugs?

Actually, I would think it would be harder to do properly with a peripheral port because of the curved surface and the water jacket. Interestingly though, I've heard that N/A rotaries respond quite well to headers with expansion chambers.

The expansion chamber doesn't surprise me a bit. At the drag strip there was a ported to the nuts 12A car and it had the typical 2-stroke ping-ping exhaust sound.

One of my old co-workers was a rotary eccentric (see what I did there?). He would spout off all about how awesome they were all the time. Yet in the 3 years I worked with him he went through 5 FB's 12A and 13Bs and blew up an FD. I've handled more rotary guts helping him rebuild them than is probably healthy.

Him: "There's nothing wrong with them once you dowel pin the barrels, replace the apex seals, ditch the emissions equipment, add oil to your gas, and rebuild them every 60,000km because there is no indication from the apex seals about when they will die and seize your motor..."

Me: "Uh, right. What killed this one?"

Him: "I won't know until I take it apart."


I still envy their packaging, though...

[Tbomb 25]

Originally Posted by merlin2111

I like the sound of this.

Me 2....i grew up in a rotary...but i gotta say a lighter miata skyactive turbo has me drooling...

[blofeld42]

http://carscoop.blogspot.com/2012/11...rx-7-will.html

RX-7 fans will nevertheless be delighted to hear that the Hiroshima-based carmaker’s chief of sports car division Nobuhiro Yamamoto told The Motor Report during the launch of the revamped MX-5 roadster in Australia that the RX-7 is set to return in 2017.
...
He added that the 16X motor is capable of producing 295HP (300PS, 220 Kw) – and that’s in normally aspirated form. Since his priorities are instant throttle response and linear power delivery, turbocharging is not very high in his agenda.

Yamamoto didn’t completely rule it out, though: “At this time, it has not been determined. Maybe later in life it will be turbo, but to start with maybe not”.
...
Built on a modified version of the next-generation MX-5 platform, the 2017 RX-7 “would definitely be lighter” than the third-generation model and “probably around the weight of the Toyota 86”, which means about 1,250 kg (2,750 pounds).

[serialk11r]

This should go in other cars section @Guff

A little disappointing specs at a glance, 295hp is about the exact same per displacement horsepower as the Renesis, so that means it's not going to hit 9000rpm like before because its efficiency has definitely gone up :/ Hopefully it's not too hard to unlock some more rpms. Seems like it'll be a pretty interesting motor though, solid state laser plugs? 4+ ignition points maybe? :slobber: Since they're taking their time, I hope they come with variable geometry ports too.

Weight is also a little disappointing considering that the rotary motor should be shaving some weight off, and that it's a 2 seater, which should shave more weight off. Hopefully by around the weight of the Toyota 86 they mean slightly less than the stripped down base version :P

[Wolfking]

2017!...So we've some time then?

[Guff]

Originally Posted by serialk11r

This should go in other cars section @Guff

What am I? Your personal butler?

Is my name in big, red letters or something? Am I supposed to be some sort of janitor? Why do you call me do your dirty work? You make it seem as if I am supposed to moderate the content on this website or something.

The nerve of some people...

[serialk11r]

Originally Posted by Guff

What am I? Your personal butler?

Is my name in big, red letters or something? Am I supposed to be some sort of janitor? Why do you call me do your dirty work? You make it seem as if I am supposed to moderate the content on this website or something.

The nerve of some people...

We all know that your job is to thank all the posts rather than moderate, it's just that your name *does* happen to be in red letters.

[bestwheelbase]

Photo from the article:



Holy shit that looks rad.

Oh wait that's a car from 1991.

The love affair will never end.

[White Shadow]

Originally Posted by bestwheelbase

Photo from the article:



Holy shit that looks rad.

Oh wait that's a car from 1991.

The love affair will never end.

All kidding aside, I always thought that generation still looks as good today as it did back in the early 90s. Other than the pop-up headlights, that body style looks very modern. How many other cars from 20 years ago can we say that about?

[dem00n]

So we have the twins to blame for this? The way the article is written, that's what it seems like or am i the only one seeing this?

Anyways, its good to see Mazda is thinking about the car guys. Hopefully this will convince Honda to make a set date for something special.