U. N. O.

i am seeking opinions on the diference btw piston cars and rotors...
Thinking about it, it is hard to find many pros for the rotor engines, and i guess it is an important part to make my decition on a buyback or not.
As of right now i stand iin the point of view that there must be a reason why mazda is the only company to persue this technology with sooo many other car makers out there, whys is it that no one else wants to mess around with rotors?
The 8 being my very first rotor car, i must admit that i am exited for it. i like to be diferente and having a non-piston car gives me that sence since 99.5 % of the cars i see on the road are pistons. But at what cost, is it really better? so far this engine has proposted to me with to pros, one being real quiet for the 'power' it generates and the 2 is just that is diferent (a psycological matter) but thats it a major turn off is that consuming 1.3 liters, it gives out CRAZY horrible mpg. And there is people who wish to have a 3 rotoe 2.0 displacement in the 8 what kind of mileage will you get? 10? .. the other major con is that it gets hot as hell, it like having a personal heater without turning on tha heater. 3 the poor power output for gas consumption.. less than 200 at the wheels.
so with all said what are really the good things to look for in the 'renesis' engine or a rotor engine .
Why doesn't other companies try to develop this type of engine, are they really reliable? what about cutting up with future technologies such us fuel cell systems? is mazda going to develop the rotor engine into that new era all by itself? i guess i really am new to the rotor engine world.! really shifting towards a piston one (sti?)
Thanks for you input in advance, this might help me understand a little better the dynamics of this engine and pershaps even to keep it..

DonG35Miata

Gotta reply to this one.

When I first asked my grandfather, a fellow car nut, about the rotary, he said "They say it is the engine of the future. And it is, because it is not here yet!" The latter sentence referred to the fact that only Mazda had the rotary and it was in a much inferior position to piston engines in the marketplace. This was in the early 1980s. He also related they had a lot of pep but burned a lot of gas. Similar to today- not a whole lot of change in 20 years.

I think in 24 months the rotary will be gone from the USA as a gasoline engine, never to return. Too many drawbacks- heat, poor fuel economy, low torque, missing power, lots of seeming production line variations in terms of wildly fluctuating mpg/power among board member vehicles, as well as PR problems for Mazda and all the issues reported on this board. But mostly, I think it will be dead because of the power and torque produced in relation to the gas burned. NOT ACCEPTABLE. As much as I like the rotary, I don't see the point of it at all anymore. "It's smooth, has few moving parts and sounds cool" and "only Japanese engine to win LeMans" doesn't cut it. From an engineering and efficiency standpoint it is a bad answer for a passenger car.

Back to my grandfather's statement. The rotary COULD have a bright future- as a hydrogen engine. Piston engines detonate when burning hydrogen. Conversely, rotaries run very well on hydrogen, and Mazda has demonstrated this.

Our fossil fuels WILL run out someday. We can make ethanol, or electolysize (sp?) hydrogen from seawater using electricity from nuclear power. If we start burning hydrogen (I want an internal combustion engine, none of this fuel cell crap!) Mazda will be WAY ahead of the game. The engine of the future: the hydrogen-burning rotary. From Mazda. A good reason for them to continue pursuing it, and probably part of the reason they do.

U. N. O.

if so then why bother and go thru this all embarresement with the 8 ? if future comes in the way you say, people will look back and remember this times, what will it make it better in the future, their word? again?
and so you say that right now pistons are the way to go, right? .. maybe we should do a poll too, pistons or rotor

DonG35Miata

I have been asking myself that question for a month now. Why ARE they going through all this embarassment? They had to have a clue as to the fuel consumption.

Because it won't be what they say, but how the product performs. That is what the problem is now- product performance in the real world. If they can make a rotary burn hydrogen and produce more power than a fuel cell, as well provide a driving experience akin to what people will have now, then they will have a winner. Who knows how far in the future this could be.

Hercules

I have to be honest, that when I first started looking for a car, I had no intention of buying another Mazda, nor did I have much knowledge about rotaries. I really didn't care.

However now being a bit more read about the car, the engine, and the reason it exists and if things play out properly... will continue to, I can give you a few words on this.

First DonG35 is right about one thing, it *is* the engine of the future. But for sports cars, and also for hydrogen (as mentioned). Mazda themselves have admitted that the rotary is not suitable for passenger cars and more suited to sports cars. As well it should be.

First, it's smooth. You can rev the hell out of it and it LOVES it. That's part of my fun in a sports car. Second, it's very *lightweight*. If you look at cars like the McLaren F1, the Ferrari Enzo, they are KILLING for mere pounds of weight. The RX-8 saves lots of weight by using a rotary instead of a traditional piston engine.

It's also small. The RX-8 engine itself is about the size of a beer keg. In fact it's so light, you can likely carry it yourself (provided you're able bodied enough to carry a keg!). Piston engines with similar power output cannot compare.

Now the torque issue... okay I admit, it's not a torquey engine. It's only in America that people obsess with the 'off the line' power and torquieness of the motor. However when you're saving so much weight, the torque becomes a non issue. You *do* have to wind out the gearbox to get the power out of the motor but even then, the car is very powerful.

In the end, look at it this way. A 1.3L (or even 2.6L if you're so inclined) produces ~240 horsepower. Nissan needed a 3.5L engine to make this power. BMW uses a heavier I6 to produce power like this. That's the beauty of the rotary. You add another rotor or increase the width, and you have gobs more power. At the price point of the RX-8 I think, that it wasn't feasible to do that because where the RX-8 is positioned in respect to other cars. It would have been nice to have 280 horsepower, but then it would also cost more money.

So to be frank... if you don't 'get' rotaries, or don't like them, you likely never will. But I'm having a blast driving a car that has a rotary engine, as are many others. And in the end, isn't that all that matters?

mikeb

do either of you own a rx8

bwayout

Maybe someone can point me in the right direction -- but why do rotary engines come out producing a much poorer MPG than a piston engine?

I'm not a scientist or enginer, but I would have thought that with a rotary engine being such an elegantly simple, more powerful and smaller machine that it would easly do much better than the average 4 pistoned engine?

U. N. O.

yes. preorder mine in fact, the second one to get the car in my area.

Elara

Only Don doesn't.

RXhusker

I think I would do a little more research and board searching before I spent too much time listening to Don "Occam's Razor" G35Miata.

Every car -- every engine has strengths and weaknesses. The rotary has many strengths for a sports car -- as highlighted by Herc. It also has a few weaknesses but I would not list Torque, missing HP, etc amoung them. Buger has posted many great thoughts on torque, hp etc. if you search or I would suggest a great article Paul Yaw has written Torque vs. Horsepower .

You will notice that Mazda is not putting the Renesis in the 6 or the Tribute or the MPV. It is however in sports cars (maybe even the Miata as an option). It's amazing that for such a poor engine the experts have named it the "International Engine of the Year 2003"

U. N. O.

true, nissan takes 3.5 liters but thats where my question is, their mpg is better. consuming waaay more they produce more power ofcouse but consume less..
engine is lighter and smaller, you add 3 one or increase the width then waht will we get 15 mpg at the sticker and 10 when in practical use?. and you last point is that a 280 hp rotary would cost a lot more, so pistons are more affordable. so what if the engine is smaller/lighter the question remains, does it perform equal, superior, or inferior than a piston? i guess the technology/time is not right for this type of engine just yet..

DonG35Miata

Need I remind you, RXhusker: The Occam's Razor theory was correct and I was right. The Renesis was down on power simply because it was not a 247 hp engine. The simplest explanation was the correct one.

Do you want to make a bet based on my 24 month prediction? I have paypal and we can settle up that way. Hercules is a good guy and he can moderate and hold us both to the bet, and we are betting on September 11, 2003. It is easy to remember September 11th. If Mazda will be selling a 2006 model year rotary-powered car in September 2005, I will pay you $50. If they are not selling any more rotaries for the 2006 model year, you will pay me $50. Do you accept the wager?

U. N. O.

perhaps because of the poor and missleading information release by the company? becuse i am sure if they take an engine right now from one of our cars, they would probably think twice about that award , don't you think? if it is an award because of all the engeneering behinde it and all the time involved and the size and the wight, etc, etc. yes it deserves it but what about what real people really cares about, performance/price/usability(mpg) in comparison to other cars in the class. I guess mazda shoot up high and it ended being in a harder fall

RX8-TX

I guess one of the reasons is its cycle rate...idle speeds are higher than a regular piston (recipro.) engine.

mikeb

good point

mikeb

good point rxhuster

R32

What would be considered more efficient?

A 1.5L 3-rotor?
Or 1.5L 2-rotor?

3 small rotors or 2 larger ones?

RX8-TX

Not only American's are obsessed with off-the-line performance. The Lotus Elise 135 has a 135bhp & 126lb-ft engine...how fast is it off the line? its in the mid 5s....of course its waaaaay lighter...1700lbs and its only an inline-4 1.8...climb up to the Elise 190 and you got yourself a rocket with rubber landing gear (I meant tires. :D )

And its not the best example, but the one I had more at hand.
Ohhh, yes, going back to the topic....I don't think an engine ca be so flawed and yet get an award of any kind. I am pretty confident that the engine has to be an enormous improvement over the previous iterations; although this is my first rotary. :D

RXhusker

Dang Don you really are deluded The Renesis engine is 247 H.P. (as J-SPEC configured) -- the US ECU map is currently limiting power output to 238 HP. That is not the rotary engine -- it is the emissions control system limiting top end power. Your x-files'esq Occam's Theory (poorly applied I might add) could just as easily be interpreted to show that the J-SPEC RX-8 makes 247 so the simplest path of logic would point to the differences between set-up and point to the ECU changes for the North American and Euro markets. By the way, Occam's Theory can not be "correct" or "incorrect", your hypothesis attempting to apply Occam's Theory may only be proven to be correct, or as in this case incorrect.

I don't practice betting or gambling, but feel free to check in in 2006 -- Yes, I am 100% confident the 2006 RX's will be hitting the highways and byways.

U. N. O.

and another question that will help and i am sure it has asked before. IF and only IF our cars/engines are the way they are because of ecu re-do because of epa/usa espec, thats this mean that japan spec cars are to 247 hp? and under what consumption of gas? (mpg)

RXhusker

I guess if you take the time to read the criteria used and how the judges scored each entry you will realize that your "what real people care about" areas are those that they used for consideration of the award.

I really think people can become jaded reading these forums -- go to any other board for any other car and you will find at least as many issues, problems, malcontents and conspiracy theorists as for the 8. Check out the Z boards, Audi boards, BMW etc., etc. You would think that all of these cars stink and have the worst quality control in the world.

The RX-8 is a great car using many criteria and it has it's downsides (like all cars). I love to drive it everyday and it has surpassed my expectations in terms of quality, performance, comfort, etc.

revhappy

I've got to concur with Don on this one. The benefits of the rotory do not exceed their costs IMHO. Sure, it is smaller and lighter with a pistion engine with comparable power. This works real well in a racing environment (to a point...I guess if u went through a tank every lap that could be a problem!!!), but in the real world with power limitations due to poor fuel economy and high emissions, its advantages are lost. While the Honda engines are not quite as small, they can produce more power, have better torque curves, have better reliability and have much better fuel consumption and less emissions.

In reality, the only way the rotory can compete is in a small 2X2, 2 seater or a roadster. However, Mazda refuses to commit to this design and instead chooses a model (true four seater, semi- luxury) that its not suited for.

The rotory does have the intangible qualities to rotorheads, but its not enough to persuade the common man.

DonG35Miata

LOL I am deluded? Denial isn't a river in Egypt, you know...

THE RENESIS DOES NOT MAKE THE 247 HP AS WAS ADVERTISED IN THE USA. It can be 247 hp J-SPEC or 900 hp Mars-Spec and it does not matter. We are talking US engines here. Spin it all you want. I don't care if it is an ECU, or exhaust, or phases of the moon. The engine does not make 247 hp. Most people on here don't even think it is making the 238 hp number you gave.

Boy am I sorry I posted again. I do see some evidence of some lucid thought here, but not much!

Didn't think you would take my bet. See you in 2006 though. I'll be back to make my victory post. Just put it in my Palm Pilot schedule.

U. N. O.

i feel that maybe but unless something serious is done about it, it will die eventually, just as it did with the rx-7s maybe 2006 will be the last year, that will make the cicle of 3 years in the market... meanwhile, pistons will get better and better it seems.. the thoought of a 2.5L 4cilinder, tubot at low psi can generate 300 hp is very compromising and to avera 18-20 in city driving!

zoom44

we have to wait for wakeech i think for a complete explanation on the fuel consumption issue. i don't keep that stuff in a part of my brain i can easily access not do i feel like doing the search.
but my quick found piece of flotsam remembers talk about the amount of time spent engineering piston engines by every company in the world that produes them vs. the amount of time spent by basically just mazda over the last 40-50 years. plus the piston engines with their amazing amount of moving parts have more "adjustability" to play with. with rotories it is basically 4 adjustments: displacement, size of ports, shape of ports and placement of ports. those can get very tricky and take alot more time and study to achieve the desired effect.