By on January 7, 2010
Poor Felix... (courtesy:citroenet.org.uk)
A few weeks ago, I wrote about Mazda’s new RX-7, scheduled for release in 2011. Well, that now looks unlikely. In fact, Mazda have put the release date as unknown, ushering the wankel warrior into the dreaded category known as development hell. Autocar reports that the development of Mazda’s new RX-7 is plagued with problems. The RX-8 had problems with fuel economy and high oil consumption and the Mazda engineers are no closer to solving them with the new RX-7. They could solve the problem by adding direct injection, but that’ll drive them into another problem. The DI components would make the RX-7′s engine weigh more than the current 13B motor, an outcome that would be in direct conflict with Mazda’s vision of cutting 100kg from all its cars in the next five years. Other problems, include lack of mid-range torque and trying to get the current engine to reach their target for maximum revs. Couple these problems with Mazda’s sales dropping 19% and the prognosis doesn’t look good.
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43 Comments on “Perennial Wankel Woes Holding Up New RX-7...”


  • avatar
    SecretAznMan

    Sounds like it’s time to forget RX and think MX.  Just make a good rear wheel drive sports coupe with a conventional engine.  Let’s see an MX-7 instead.

    • 0 avatar
      no_slushbox

      Exactly, the Miata is just a shortened RX-8 with no roof. They have the same platform and suspension. The Miata handles brilliantly with a piston engine, but people cry that the 500 pound heavier RX-8 would have its balance ruined by the Miata’s piston engine. I, for one, could live with a more reliable, much more fuel efficient RX-8 that “only” handled as well as a Miata.

      I’ve driven the NC Miata and I’ve driven the RX-8, and the Miata drives better. Sure some of that is because of a lower overall weight, but I never thought: damn, this Miata sure is nose heavy with its piston engine. Not only did the RX-8 handle worse, but it felt gutless compared to the piston powered Miata.

      RX-8 sales would increase dramatically if the 170 HP engine from the Miata was put in it (easy, they share a platform) and it became an MX-8. Not to mention that Mazda could put the 2.3 liter direct injection turbo in the RX-8 right now. Like Legos. Instead of bankrupting itself trying in vain to fix the rotary’s multiple flaws.

      Mazda completely mind f*cks anyone that wants a rear wheel drive manual transmission daily driver, it puts the impractical (gas guzzling, unreliable) engine in the practical (hard-top, 4-seat) car and the practical (bulletproof, fuel efficient, but relatively powerful) engine in the impractical (convertible, 2-seat) car.

    • 0 avatar
      James2

      @no_slushbox
       
      Every car company has its “this is how we do it” way and the Wankel is Mazda’s. Although limited to one model, they must feel the rotary is what defines Mazda’s zoom-zoom image –and are prepared (they must be) to sacrifice logic/common sense/whatever to feed their Wankel god.
       
      Otoh, I don’t think RX-8 sales would improve by decreasing rated horsepower. Instead, for the RX-8 (or -7 or…) Mazda should revive the sweet, K-series V-6 and apply all the new technology (VVT, DI, etc.).

    • 0 avatar
      no_slushbox

      People don’t buy the RX-8 for power, I think it would do well with a slightly less powerful but much more reliable and fuel efficient engine.  But, like I said, the MazdaSpeed3′s 263 HP, 280 lb/ft direct injection turbo could be the optional engine.  It’s the same basic engine as the Miata’s, so it would fit well, and it’s significantly more fuel efficient than the less powerful (232 HP, 159 lb/ft) rotary.  And the MZR 2.3 DISI Turbo is not living up its potential in the MazdaSpeed 3 because of cost considerations and FWD limitations; it could do above 300 HP in an MX-8.

      We’ll have to see if Mazda is run by the kind of stubborn idiots that are usually associated only with Detroit auto companies, or if it is smart enough to give up on the hopelessly flawed rotary and focus on the great cars that it could be making now.  Toyota is making a mistake trying to bastardize the Impreza into a RWD ae86 successor; Toyota will be able to buy the best small RWD platform on the market from a liquidated Mazda soon if Mazda doesn’t stop chasing fairies.

  • avatar
    Redshift

    The longer is takes Mazda to get a new RX car out, the longer I get to keep my RX8 (and 7) before it comes time to upgrade.

  • avatar
    Paul Niedermeyer

    Time to put the rotary in the museum of almost good ideas that almost was good enough if you kept throwing almost enough money at it.

  • avatar
    gslippy

    If rotary-powered cars featured outstanding performance in some category, any category – attributable to the engine – Mazda’s persistence with it would be laudable.
     
    Instead, it just seems laughable and quixotic.  Being able to claim the most HP for the lightest engine doesn’t matter to anyone.  Lots of sporty cars offer good weight balance and handling, too, so what alleged benefit does the rotary offer?  Fuel economy and longevity are not on the list.

    I think it’s time to archive the rotary; Mazda’s done a great job with it, but the demands of modern vehicles have outpaced its development.

    • 0 avatar
      no_slushbox

      The only application where the rotary makes any sense is in sports bikes.  In a <400 pound vehicle every bit of engine weight starts to matter.  And sports bikes aren’t expected to be reliable or fuel efficient (hell, they don’t even have to comply with CAFE).  Yet no motorcycle maker, not even those as well financed as Honda or BMW, is wasting its time with the rotary.  Suzuki tried for a short while and gave up.

      You would think that would be a wakeup call to Mazda, but maybe Mazda wants to die.  I guess I should be thankful that Miatas are so well made, the current ones might have to last.

  • avatar
    seabrjim

    I will keep my miata, It handles as good with the right tires, springs and a strut brace. It also gets at least 300 miles from every tank no matter how I drive it. Thats right, the tops goes down too! Even with 15,000 mile oil changes( Mobil 1 with a fresh filter at 5,000 and, 10, 000 miles) it uses no oil.

  • avatar
    tced2

    The rotary engine has several stories around it.  
    The first  is the reason Ford ended up with a significant stake in Mazda was that the rotary engine did not get good gas economy – and in the first gas crisis (1974) – Mazda’s vehicles didn’t sell well because they had wankel engines – Ford came in to save Mazda.  
    The second is the affair of GM buying the North America rights to the wankel and spending (a lot) of money on fuel economy, durability, and emissions issues – and eventually giving up not solving the problems.  
    The third is that the AMC Pacer was designed for the (never-to-exist) GM wankel engine – so the AMC straight six was wedged into the engine bay with a resultant huge transmission hump in the passenger compartment.

    • 0 avatar
      Robert.Walter

      Actually, I think it was Sumitomo Bank who came to the rescue of Mazda, and then when they looked at how to restructure it, they too realized that Mazda was “too big to be small, and too small to be big” and began shopping their equity … For different reasons, they couldn’t find a “Japanese Solution” (alway the preferred way), and in the end, Ford made the investment, and later increased it, and later decreased it, but along the way, found good synergies …

    • 0 avatar
      MadHungarian

      Definitely true  that the Pacer was originally designed for a rotary.  Also, GM threatened to produce a rotary Corvette on and off for a while in the 70′s. 

  • avatar
    Matt51

    The sad thing is – the Mazda rotary, the most advanced in the world – is the ideal small helicopter engine, whether manned or unmanned. More reliable than a piston engine, matching a gas turbine. A 300-500 hp gas turbine costs anywhere from $200,000 to $500,000.  Sometimes the initial cost is low (they give the engine away) but then they make up for it on hot section overhauls.  Same performance as a gas turbine, but 5-10% of the cost.

    • 0 avatar
      Robert.Walter

      If this is true, and I’m not saying it isn’t, then how come it has not found favour with military applications which are not emissions sensitive?  What about use as a power-source, running in the optimum range, for a HEV?

      BTW, at least at one point, Mazda was touting their rotary as being an optimum configuration (yes, all OEM’s seem to say this that one would think Max Bob Lutz writes all these things) for burning H2.

    • 0 avatar
      MikeInCanada

      In the late 1980s the John Deere company made a series of industrial wankel rotary engines of varying sizes. My understanding is that John Deere purchased Curtiss-Wright’s rotary engine program, did some development of their own, then sold the rights to RPI (Rotary Power International) – which subsequently went TU.

    • 0 avatar
      fincar1

      In fact the Mazda rotary specialist in this area a few years ago was spending quite a bit of time on converting RX7 mills to aero engines.

  • avatar
    TrailerTrash

    We praise other manufacturers for keeping the R&D going inspite of cost.
    We bash American manufacturers for giving up on tech early while others stayed the course and then profited when the markets opened.
    Well, we should praise Mazda for this philosophy.
    Perhaps there is a reason the rotary is still in play…hydro power?
    Personally, I would love to see them borrow  from Ford and drop in the upcoming 4 twin turbo.
    Any turbo!

  • avatar

    I would love to have an RX-8 as it is with a normal piston engine. I really like the sports car with the useful back seat and 4 doors. (I drove one for a week when I was writing about it in ’04.) Yeah, the dynamics might suffer slightly from the heavier engine, but it’s so good that it would probably still be damn good. It’s a light lighter than the 3 series, which to me is a big plus.

  • avatar
    ihatetrees

    I used to think that design elegance combined with advances in metallurgy and electronics would make rotaries viable.  While somewhat true, those advances have also aided piston engines to the point where rotaries have lost (relative) ground (especially since many new car customers think they have a right to ignore maintenance).
     
    Don’t get me wrong. For the money, an RX8 (with a manual) is wicked fun and a great value.  Perhaps a DSG would make the car more appealing to the clutch-phobic and cupholder loving demographics.
    I’d like to see Mazda keep it, but my bet is that beancounters will end this car.

  • avatar
    Russycle

    I got in to a small flame war the other day with a guy who thought rotaries were the ideal engine for small, fuel-efficient cars.  Wish I had some of what he was smoking.

  • avatar
    davejay

    Hm. I wonder if using a rotary in a car like the volt would make sense:

    1. the small size and weight savings would help offset the battery size and weight

    2. the simplicity and reliability would be a better match for the low-maintenance, high-reliability nature of electrics

    3. the smoothness of operation would make driving in “extended range mode” more palatable, and the starting/stopping of the engine much less noticeable

    4. perhaps the ability to run the engine more or less at a constant speed might allow changes to the design that improve fuel efficiency

    5. the issue of low torque would cease to be an issue
     

    • 0 avatar
      chaparral66

      1.  Rotaries really are not lighter as a whole than a piston engine.  Look at Mazda’s experience in LMP2, they were able to replace the rotary with a much lighter piston engine.  I think they generally are lighter, but the difference is pretty small.
       
      2.  Rotaries are “high-reliability”?  They are simpler, but more reliable?
       
      3. This is a pretty good point
       
      4.  They will never be as efficient as a piston engine.  So why would you try and make a very fuel efficient car and a less efficient engine?
       
      5.  Yes, the low torque would cease to be an issue.

  • avatar
    poohbah

    I too love the fact Mazda is still trying to perfect the rotary as well as hate the fact they are failing.

  • avatar
    Detroit-Iron

    I read that rotary is good for hydrogen engines but I can’t remember why.

    • 0 avatar
      chaparral66

      It is less about being good for hydrogen, than being hydrogen being bad for piston engines.
       
      Hydrogen has effetively a very low octane number, so the compression ratio needs to be fairly low.  Since rotaries can not run as high of a compression ratio as a piston engine, this makes the rotaries performance on hydrogen closer to that of a piston engine.  Also, the increased flame speed of hydrogen helps the rotary since that can be a limiting a factor.  Niether of these issues make it better than a piston engine if both are using hydrogen, it just makes the makes the rotary closer to a piston engine.

  • avatar
    thesal

    I think a clear sign to give up on rotary is when the little brother (mazdaspeed3) outguns and likely outperforms on a track when compared to the “halo car” for a whole lot less money new.

  • avatar
    Jerome10

    Mazda needs to not worry so damn much about the fuel economy….especially if this car is a new RX-7.  Rotary heads don’t get 2 craps about the fuel economy.  Give it the power and you’re set.
     
    And for those talking about how great the Miata is with a piston engine….that’s the car that should have the rotary.
     
    This is Mazda’s soul.  Rotary = Mazda.  Doesn’t matter if maybe it no longer quite makes sense.  Straight 6′s probably don’t really make sense any more either, but its what makes BMWs BMWs.  Pushrod V8s probably don’t make sense either.  But would a Corvette be a Corvette without one?  Porsche and a Flat 6? Same thing here.
     
    I hope they make it work.  I’ve been dying for a 2 door, true rotary coupe from Mazda.  The RX-8 is great, but I don’t want the whole half sedan/half coupe thing.  Give me a drop dead gorgeous, fantastic driving, rotary powered sports car.  Instead the RX-8 appeals to no Rotary sports car drivers and also doesn’t appeal to families because wifey doesn’t check the oil.

    • 0 avatar
      tced2

      But there are folks in the District of Control who dictate fuel economy.  If you don’t meet the specs there is a big fine (the customer ends up paying).  The RX-7 would end up being much more expensive.

    • 0 avatar
      no_slushbox

      The BMW I6 makes a lot of sense.   BMW doesn’t make large FWD cars so it doesn’t need a modular V6 that can easily go longitudinal or transverse.  And it means that various cam timing and phasing technologies only need to be applied to half the number of camshafts.

      But, speaking of Porsche: what used to really identify Porsche was air cooled engines.  Yet Porsche stopped making air cooled engines and the earth did not stop rotating.  Porsche has been as successful as ever and made its best car ever, the Cayman.

      And the problem with the rotary isn’t that people didn’t change the oil, it’s that they didn’t top it off every 100 miles like some oil burning POS.  Blaming customers and oil is a good sign that a company made a crap engine.

  • avatar
    Morea

    >>Yet no motorcycle maker, not even those as well financed as Honda or BMW, is wasting its time with the rotary. Suzuki tried for a short while and gave up.<<

    In the 1980s the Norton motorcycle company had some success with rotary engined motorcycles for both street and track use:

    http://en.wikipedia.org/wiki/Norton_Motorcycle_Company#Wankel_engine

  • avatar
    Bunter1

    Let’s keep in mind that the Otto cycle engine has had hundreds of companies refining it for 150 years.  Only a handful have been working on the Wankel (off and on) for the 40-50 years.
    I’m glad somebody is continuing to develop this engine, I doubt it is close to it’s true potential yet.

    Bunter

  • avatar
    mtymsi

    I believe Mazda thinks the rotary engine is a market differentiator when in reality both Mazda buyers and potential buyers don’t even consider it because all the mainstream models are conventional engines. It is obvious that Mazda is unable to develop the rotary to the point that it is a viable offering. Equally obvious is Mazda doesn’t have the money to continue this frivolous pursuit. Mazda needs to forget about rotary engines and move forward. They also need to replace their design staff responsible for the fugly current 3 and 6 models. At the rate they’re going the end is in sight.

  • avatar
    ccd2

    If I were a betting man, I would bet that the 2010 model is the last one for the RX-8.  Mazda has been selling less than 200 per month nationwide.  Mazda made a number of changes to the car in ’09 which should improve reliability.  But improving reliability does not mean that the public impression that the car is unreliable will change.  Even if reliabilty has been improved, the gas mileage torque and hp have remained pretty much unchanged since the car was introduced in 2004. 

    After 7 years with minimal changes, Mazda needs to do something and I doubt there is much Mazda could do to change the generally negative public perception of the wankel.  Especially given Mazda’s fiancial position and these economic times, I expect the RX-8 to fade into the sunset after this year.  We may be teased with rumors of a new RX-7 in the future, but I doubt a new RX-7 will ever materialize.

  • avatar
    ccd2

    I’ll add one last comment.  After reading the comments here and elsewhere and giving it some thought, Mazda is wasting its time introducing any new car with the current R2 engine.  They need a way to address the shortcoming of the Renesis II engine or let it die.  That means perfecting the new wankel, making is a hybrid, adding hydrogen or SOMETHING that addresses torque, hp and gas mileage to the public’s satisfaction.

    The other point is that people are tired of teasers from Mazda concerning the new RX-7.  The future car garners relatively few comments here and elsewhere because people are tired of idle speculation with little to no concrete info.  It’s put up or shut up time.

  • avatar
    Matt51

    A 300 hp Mazda rotary can run reliably all day at 300 hp. Normally a 300 hp piston engine runs very little time at 300 hp. The Mazda rotary has proven itself more reliable than piston engines in small airplanes. If we look at Robinson trying to sell its first turbine helicopter using a 300 hp Allison gas turbine, it would be far more affordable, and just as reliable, using the Mazda rotary. I would love to see a small helicopter manufacturer pair up with Mazda, or see Mazda enter aerospace, as Honda has done.

    • 0 avatar
      ccd2

      And that may be the future of the wankel IF it has any future at all.  Think of it.  This is a website for car people.  A new wankel based car has the potential to be one of the more interesting car introductions in any year and nobody cares.

  • avatar
    Matt51

    Someone is selling two Suzuki Hayabusa engines tied together into a V8 for $30,000. This gives 400 hp at 200 lb weight. 2 hp per lb. My guess is the new Mazda Renesis will match this, because they have new advancements, including the “block” or three side plates, will be made of aluminum instead of cast iron.  I would guess the engine alone could be purchased from Mazda for about $10,000.  The 300 hp at 200 lb matches the Allison (RR) model 250 gas turbine, but at better fuel economy. Running these 400 hp engines at 300 hp should give good life for flight applications. 300 hp at 200 lb is important, as this is large enough to allow for a safe (1200 lb) helicopter of adequate size.
    So for the first time, piston and rotary engines now are matching the gas turbine, but at much lower cost. This is going to be revolutionary in terms of low cost flight. There is no such animal as a “low cost gas turbine”.  Just the difference in cost for the hot section overhaul is going to be astonishing. You could throw away the Mazda engine and put in  a new one for $10,000, as opposed to a $200,000 hot section overhaul of a  turbine.
    Another advantage of the Mazda engine is it turns at lower rpm than the gas turbine, so you need less reduction gearing in the helicopter.

  • avatar
    RotaryMan91

    Wow! I can see that there a lot of “non-rotor heads” responding to the possibility of Mazda cancelling the new RX-7.

    First of all, the rotary’s day is not over as far as its ability to perform as well or even better then a piston engine. It is today as good as it has ever been. Yes, there are some problems with getting the emissions correct and fuel mileage right. But, those are problems the Mazda engineers can work out just as they did upon the debut of the RX-7 to America in 1979.

    The rotary has proven itself a powerhouse in many applications, but specifically on and off of the track. Mazda’s rotary has been penalized so many times in racing because they are simply, “too fast for the competition”. But even when adding weight to these rotary cars, they still went out and became the first sport car ever to reach 100 racing victories faster then any other sports car in history. Their endurance is unprecedented. All this racing performance has and continues to translate to its production cars with of course the RX-7 and RX-8. The RX-8 may not have the performance of the beloved RX-7, but it is still no slouch.

    It is true that we “rotor heads” have long been disappointed with Mazda for not putting the engineering over the years into developing either a very powerful 2 rotor rotary or a 3-rotor rotary. Mazda seems to have gone with light weight and less HP concept in competing with the likes of Datsun/Nissan, Toyota, and Porsche over the years. In racing, the rotaries blew away the aforementioned other cars as well as the ‘American muscle’ with championship after championship. On the street, they were as good or somewhat off their competition except when it came to the 3rd generation RX-7. With 255hp, 0 to 60 in the mid 4 seconds and a top speed of 161mph, every rotor head felt that Mazda might be getting ready to move the RX-7 into the “super sports car” category. But no further development was made due to the public’s lack of interest at the time for not only the 3rd generation RX-7, but sports cars like the Supra, 300ZX and others. The SUV and sports sedan craze was taking over the public interest at the time.

    The rotary engine is not ready for the “scrap heap” or as one of you put it, retirement to the museum. If you truly knew the history behind this wonderful engine especially in all of its forms (2-rotor, 3-rotor and 4-rotor), a lot of you would change your mines about it. It was Mazda’s 700+hp prototype sports car that was the first Japanese manufacturer to win the infamous 24 hours of Le Mans in 1991 by several laps over the likes of Porsche, Mercedes and Jaguar. Today, it is the RX-8′s in GT racing using the 3-rotor engine (410hp)that is once again, has the competition crying foul because the cars are powerful and out handle the others so much better.

    I would love to see Mazda offer a Special Edition Miata with a 20B rotary, designated MX-5R; with the “R” standing for “rotary”. Base hp for a 3-rotor is 310 regular aspirated.

    Thank God that the Mazda engineers over the years have not been detoured by the nay sayers as I have read here. Chevrolet and Mercedes couldn’t produce a viable rotary engine car. But Mazda did and put it on the map as both a production and racing applications. Remember, that it was the RX-7 that was the first that saved the Mazda Company from bankruptcy. And yes later the Miata did the same thing. But no RX-7 would have originally meant ‘no’ company to create a Miata for a second salvation.

    I hope Mazda hangs in there and starts an even more serious development into not only the 2-rotor engine, but the 3 and 4 rotors as well; and yes, come out with that 4th generation RX-7 with at least 300hp.

  • avatar

    I get the confusion from some people. The MX-5 is such a joy to drive. It begs the question why work so hard on a engine, whos research only benifits one model in your lineup. I have a ’88 RX-7 and I love it. It’s old, but i love the way it sounds and drives. Some people might just buy em for the fascination in the motor, that’s what first drew my interest, plus I just love the 80s sportscar look.

    I want the rotory to live on, and I think there are two main things mazda needs to do to make it happen.

    1. Find another venue to profit off of the tech, a single car model is not going to cut it, especially not now, rotory’s are for sportscars, if your thinking practicality and back seats why the hell are you thinking an engine that, if it’s lucky gets 18 miles to the gallon. I’ve read a few articles, and posts about them being used in small aircraft. Sounds like a good place to start. Then your development costs see a larger market of return.

    2. Maybe it’s cost, trying to keep the price down? Or wieght. But Mazda needs to reunite the rotary and the turbo. The rotary engine was born starving for forced induction. A belt driven supercharger might be better still, alleviating even more of that low end grunt issue. Without it’s turbo, the everymans rotary just falls into mediocrity in the current environment of engines, with piston motors seeing the benifits of being researched by every car company and rotaries just having 1.


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