hornbm

iTrader: (1)

Well I know this topic has been beated to death....

But did anyone else notice that in the Road and Track RX-8 insert, under the mazdaspeed section, it says "look for this car to come with a 300 plus bhp turbocharged rotary"

Hercules

Still speculation. I read an article from the lead rotary engineer at Mazda who said that he'd preferably like to increase rotor width and find more weight saving methods instead of using forced inductuion and related plumbing.

RX-8 Zoomster

Herc,

Honestly, I would prefer the forced induction & plumbing. That will enable us that are buying the RX-8 now to mod our cars later. I'd rather do that than having to worry about dropping in a new engine $$$ or trading our cars in for the MPS version.

Add the parts mod along with aero kit, spoiler, etc, and you almost have an identical Mazdaspeed version of the RX-8.

Don't know how much each option would weigh, but I would think a wider rotor (engine) would weigh more than the turbo parts. Anybody have an idea?

lefuton

since we're paper engineering i would have to totally guess at 10mm wider rotors would weigh less than 2 turbines + plumbling. unless you're talking about like 200mm wide rotors or something...

Hercules

This is not to mention of course, that Mazda has had a bad history with rotaries and turbos and even if they can get it working 100% without a problem, the 'idea' of marketing a car that was terrible in this regard due just to the turbo and overheating causes a severe problem.

It's smarter to go naturally aspirated, because first; turbos can be installed aftermarket. There is no throttle response better than a naturally aspirated car, I don't care how non-laggy the FI is. And lastly, since Mazda has had a shaky history doing this in the past it's a lot easier to sell the car.

And that's what Mazda is doing... while we may all love the car for its performance price and looks, Mazda is out to make money. It's a business. And any good business knows that the best way to make money is to offer a product that appeals to the most people and draws the biggest revenue.

Going with turbos will alienate a lot of buyers who have had experience with the old RX-7s. The idea that the RX-8 right now is naturally aspirated is one of the reasons that I started looking into this car and now have one on order. Had the RX-8 been turboed directly from the factory I'd be worrying too much to even have investigated rotary engines and what they were all about; now I'm better informed about it.

Besides the MAIN reason I like to see naturally aspirated is because it does wonders more for engineering than going with FI. Look at BMW for example; their engineers have refused to resort to turbos to get the power from their engines. What has resulted is probably the best engines in the world being developed. The I6 from the M3 makes 333 horsepower, with a mere 3.2L displacement. No other company can match that in piston power. The fact is, that if Mazda decides to take the hard road, they will benefit the development of the rotary far more than just slapping a turbo on and making it work.

I'd rather they get 300 horsepower from engineering work than from a cheap and easy FI method. It's that kind of striving to succeed attitude that I appreciate much more than taking an easy way out.

Of course, this is just my opinion.

revhappy

Wouldn't increasing dispacement be "cheap and easy" too? Personally, I'd like to see a higher compression ratio that yields something like 280 HP with a 10,000 RPM redline. If you then drop off 200 pounds, I'd be in heaven. :D . Of course, I'm not a "torque" guy so this option would not be for everyone.

Sputnik

As long as Mazda doesn't do something like lower the compression for a turbo engine or include a stronger e-shaft.

---jps

artmt

True for turbos, but not necessarily for supercharges.
With a sc throttle response is usually good, and Mazda had good history with sc Millemia. Besides, sc is light.

desmo996

I agree with hercules. The RX-8 should be naturally aspirated. More parts in an engine, moving or not, will decrease reliability. Simple engineering goes a long way ("KISS= Keep It Simple Stupid). I would rather see a three rotor engine to increase torque.

neit_jnf

What about Honda with the S2000 and most Ferraris ?

medcina

Though both Honda and Ferrari make some impressive engines, I don't think either makes a 6-cylinder that puts out numbers like the M3. Honda makes a great 4-cylinder and Ferrari makes great 8 and 12-cylinder engines.

rxtreme

iTrader: (1)

Ummm, Honda still leads the way in the most HP/liter in any production piston engine, and it took BMW ten years (after Honda) to produce a 6 cyl. to reliably rev happily up to 8 grand! In addition, BMW did it with an I-6 (verses a V-6 for Honda). Some of BMW's work should have been cut out for them because it is my understanding that I-6's require less balancing for higher RPM's. Why Honda doesn't "engineer" a more powerful V-6 (over 320 HP) for the NSX is beyond me.


I totally agree with that. However, in the end, it's about how well the car can perform, either against its competition or in comparison to the RX-7. I hate to bring up the numbers card, but those performance values (0-60, 1/4 mi., skidpad, etc.) hang heavy with potential buyers. I don't think Mazda would add either to the Renesis this time around unless it could be done reliably. There certainly would be no issue with torque if a turbo or SC were added. I wonder what type of HP/torque figures were talking about with a bigger (2.0L) Renesis? How well would a RX-8 (or new RX-7) perform with this new bigger rotary? Then there is the question of gas mileage: Would it be acceptable or absurdly low? Whatever path Mazda takes with the Renesis, I just hope it performs and does it reliably.

ProtoConVert

True BMW has had this reputation. However, the next generation BMW engine series will include a ~380hp turbocharged inline six as the engine that comes before the /M version. This is because quite simply it is impossible to extract more than 343bhp from the 3.2I6. So, yes, even BMW has to drop the hardcore NA reputation for turbos. Which I find unfortunate but temptingly understandable.

My take on Turbos for RX-8 is that it MUST be possible for at least aftermarket forced induction. Otherwise, competition (TT 350zx, WRX, etc) will outpower RX-8 if only a "stroker" kit is offered, which I dont think would be that much less difficult of an install than turbo's. If only a stroker kit is offered and supported, RX-8 will be relegated to a niche car. Furthermore, was it not the case that the peripheral port location caused most of the reliability issues with RX-7's?

hornbm

iTrader: (1)

Any turbo engine has to have lower compression to allow for more boost.


And furthermore, its not talking about the regular rx-8 being turbocharged, but the MAZDASPEED RX-8 being turbo charged. So there will allways be a N/A option available to those who dont want a turbo.
The artical never said weither they would go with twin turbos or not. My guess is they'd go with a single turbo setup for simplicity and weight.

cueball

I have also heard this and was at first very disapointed. But the turbo engine isn't their highest end engine. It is, like you said, made to bridge the gap between the 330 and the M3. This makes it more acceptable because it does not force the true NA enthusiases to buy a turbo. Still, I am sad to see BMW turbo their cars.

RacingDynamcs

since we're picking at m3 motors leme jus say there is a guy in NJ with a 1400HP i6 97' m3 motor in his car =) about 12grand into the motor...

racrx

The M3 engine we speak of here may not be the poster child of reliability. The E46 M3 engine has experienced a substantially uncommon amount of engine failure (see link). http://members.roadfly.org/jason/m3engines.htm It's possible that BMW may have reached limits in extracting big reliable HP numbers from small displacement, high reving N/A engines. Maybe thats why they are moving to turbos in some future models. But since the rotors in a rotary engine only turn at one third Eshaft speed, wouldn't a larger displacement (wider rotors) rotary go a long way in making more reliable power levels? Just a thought.

rxtreme

iTrader: (1)

I think the I-6's require longer connecting rods than comparable V-6's (comparable in displacement). I believe they either require extra rod bearings or beefed up rod bearings because of the travel and angles the connecting rods follow being all the cylinders are inline. Longer connecting rods, more travel for piston movement, and sharper angles during connecting rod travel all make a reliable 8 thousand RPM redline an interesting engineering project. Oh, well, maybe the turbo version will prove more reliable than this one.

Sputnik

Not necessarilly. Mazdaspeed did not change any internals for the Protege'.

---jps

racrx

I agree rxtreme to an extent. I've read that the piston speed in the E46 engine is very close to that of their F1 program. That 's asking alot of an engine for everyday use and it's a trade off that BMW accepts to get the level of performance that was targeted for the E46 car. If you want to spin a piston engine at those kind of rpm's you typically go with an over square combo, big bore short stroke. You make more power at the upper register but lose the torque down low that BMW needed, a lesson they learned from the first E30 M3. From the E30 they learned that torque is a more important trait in the U.S. marketplace than over in Europe where high reving over square engines prevail. One nice thing about the rotary is that everything mentioned above is irrelevant. They do share the same trait as an over square piston engine though, not enough torque! That's where the turbos help. I don't think my RX7 would be as much fun to drive without the (yes complex heat generating), turbos.

Hercules

The M3 engines that failed were created during a specific build date. That's why now all the engines are perfect.

And they are NOT moving towards turbos so I don't know where you read that. Their engineers, if you read Car and Driver a few months ago, despise the idea.

racrx

Time will tell if they're perfect!! I'm not willing to plop down 50k plus to find out, are you? The turbo part was not in reference to the M cars. I saw it on another web site, can't remember which right now, that it was being considered for one of the upcomming sedan models. Please understand I'm not bashing BMW as I also own a 330ci that I'm quite happy with.

Hercules

If I had the money for an M3 you'd be I'd buy one. The engines have had no problems after that build date, and everything is under warranty so it's no big deal

rxtreme

iTrader: (1)

The E46 I-6 still has the same engineering as the other E46's--really long stroke and blistering fast piston speeds. They may have repaired the oil delivery problems to the rod bearings but that still doesn't take away the amount of stress being placed on the long connecting rods and associated bearings as a result of that piston speed. As racrx mentioned, Honda can get away with it because of their over square design on the F20 (S2000 engine) and the NSX's "V" design vs. inline further helps to reduce stress on the aforementioned parts. Anyway, this is getting off subject--I really don't care if they turbo the renesis or not. Just make it reliable and perform. If they can turbo the car and make it (or close to) as reliable as a NA rotary, wouldn't that be a engineering feat in itself? Let this NA RX-8 build the publics' confidence back in the rotary and then introduce a reliable turbo rotary (if that's the path Mazda wants to take). Just my opinion.

RacingDynamcs

someone get mazda to shuv a 4rotor rotary into the next rx7 and the **** with piston power =P

:D :D :D