RIWWP

iTrader: (2)

Even a perfectly sized turbo will still drive and feel different than a supercharger, and some people will always prefer the supercharger differences over the turbocharger differences (and vise versa). I think that is what Talan is saying.

Brettus

iTrader: (2)

Sure - I was just pointing out that a properly sized turbo is a very different beast to a large laggy one . People that go on about the linear feel of a SC are probably comparing with a laggy setup .

If i was to compare my greddy 60-1 setup to that of a maxed out Pettit for example ... there is not one area of the torque curve where the Petit even comes close to matching it . But there is probably a point ... for the first 0.5 seconds of WOT where the Petitt has better response.

RIWWP

iTrader: (2)

People that prefer S/C don't prefer anything that can be pointed to on a dyno chart

But that's a different argument.

Brettus

iTrader: (2)

That is because they are in denial ....lol

RIWWP

iTrader: (2)

No, not really. I've driven quite a few different engines and forced induction setups, and currently daily drive a T/C'ed Miata. I prefer T/C for maximum power and for the simple mathematics of re-purposing energy, but maximum power hasn't ever been high on my list of what I like. Dyno charts only test full throttle, but driving at less than full throttle is where I have the most amount of enjoyment out of a car, and for that, S/C driving dynamics are far more appealing. 50% throttle on a S/C car has a significantly narrower range of torque being requested than 50% throttle on a T/C car, because your manifold pressure will be roughly the same regardless of where you are in the RPM range. For a T/C car at 50% throttle, you could be in boost, at max boost, still in vacuum, all based on what you were last doing and where you are in the RPM range (and the various turbine/intake/exhaust choices). That is an attribute of T/Ced cars that I find very unappealing.

Most people that prefer a S/C car have trouble explaining why they prefer it, and the T/C guys are usually unable or unwilling to see what they are going after, because it is a completely different goal, one that can't be described in black and white or by clearly defined numbers.

Like try to find someone describing the actual experience and feel difference between a high compression low boost engine vs a high boost low compression engine in the same car. It's nearly impossible, since the huge vein of people that boost only for max power ends up devolving the discussion into peak power. People that are interested in high compression low boost are never after max power, and that is a completely uncomprehendable goal by people that discuss and build boosted engines.

Me? If/When I need an engine rebuild in my MSM, I'm going to be rebuilding for at least 11:1 CR, possibly higher, and turning down the boost.


Yeah, I'm a heretic.

Brettus

iTrader: (2)

You might want to re- read what you wrote there ......... lol



I do understand what you are saying about part throttle . I went to great lengths to make part throttle more controllable on my previous (57trim) setup . In the end I had it so good i could increase boost in 3-4 psi increments with the throttle . That plus almost zero lag and I had a real hard time understanding how a SC could possibly be any better in any way shape or form .

RIWWP

iTrader: (2)

Uh...ooops Fixed.


Yeah, I'm up to around $5k spent on my MSM to keep improving part throttle. On the factory ECU it was bad enough that I got angry every time I drove it. On the dyno the problems were never visible, but were the overwhelming problem with the car driving it normally.

S/C achieve that naturally, T/C usually means lots of trouble to get it to behave properly, and usually increasing the boost is contrary to any efforts you make in that direction. It's that simplicity that is one of the major points of attraction.

Brettus

iTrader: (2)

It's actually pretty simple - i tried splain'n what i had done to achieve it years ago and was met with a wall of disbelief from a couple of resident 'experts' of the day .

RIWWP

iTrader: (2)

I'm not shocked at that response.

I'll send you a PM, because I'm curious.

ASH8

RENESIS Rotary Development by Mazda Employees in (ON) their own time.

Without this dedication the RX-8 would never have been born.

Image Training flash from Mazda (offically) back in 2003....

WaitingforFI

iTrader: (1)

The question is, is this still happening, and if so, is there a financial case to put it into production.

blckninja

iTrader: (1)

I think that question is based on what is the mileage and CO2 emissions? I think that in order for this to be feasable, both the mileage has to go up, and the emissions has to go down. I'm only guessing but from what I understand that's going to be the roadblock, and a big one at that.

Could happen, but i'm not that hopeful.

EDIT: Ended up reading/skimming the whole thread, only took about an hour. Yes, while the wording from the CEO can be taken either way, until they oficially announce that the R&D for rotary engines is kaput, I believe there is still a chance to see another car. Like others have stated they have been doing lots of research, especially with alternative power sources. Would be interesting to see if they do that, would satisfy both the emissions and mileage issue.

Also for the person that said the WRX and Evo aren't sport cars, they are production rally cars! Does that not qualify as a sport car?

9krpmrx8

iTrader: (46)

No.

blckninja

iTrader: (1)

Yes.

Anyway back on topic, both Topspeed, Autocar, Autoweek posted the same article, I have no idea where either of them get their information and they all basically say the same thing.

New Mazda RX-7 Could Get 250-Horsepower Rotary Engine | car news @ Top Speed

New Mazda RX-7 design, styling and on sale dates - Autoweek

Mazda RX-7 to return in 2016 | Autocar

RIWWP

iTrader: (2)

Flip the question around. Does that mean that the 8 is a production rally car? People usually make "sports car" into a bigger bucket than it really is, while still retaining a narrow definition and smaller bucket for all the other performance car types (hypercar, supercar, rally car, muscle car, hot hatch, roadster, etc...)

Cars are what they are. Not being able to all be lumped into "sports car" too isn't an insult to them.

RIWWP

iTrader: (2)

Read the first line in topspeed:

They literally just make reports based on what everyone else is reporting, without actually doing their own research.


They are also just regurgitating the same rumors over and over, using image renderings that don't follow Mazda's current plans, and making up whatever they want as they go along.

blckninja

iTrader: (1)

Totally didn't read the first line, I just skimmed over it and missed it, wow...

I figured that most if not all of it was going to be either a rumor and/or fake, I just didn't know how much would be. Was hoping that some of it might be true but I guess that was too much to hope for...

9krpmrx8

iTrader: (46)

Yep and most of the BS articles are just to increase traffic to their sites, they could care less about the accuracy of the information. And blckninja, the Impreza and lancer are compact sedans, not Sports Cars. Making a compact sedan fast does not make it a Sports Car.

RIWWP

iTrader: (2)

Typically, the individual quotes from Mazda people can be assumed to be accurate (if perhaps varying interpretations). The editors just expand on what they think from there and make up stuff (or take from other magazines) to fill in the gaps.


This is literally the only actual content in those articles:
Which only suggests that he isn't involved in building it. And that quote a lot older than the article.

WaitingforFI

iTrader: (1)

I am of the mindset that we will not see another production RX-7 / RX-8 style car from Mazda for awhile. the CO2 / NOX emission standards can not be met with the rotary combustion cycle. If by some chance they were able to hybridize their setup, add direct injection and lean burn technology, then maybe. But I do not see the economies of scale to justify it.

200.mph

iTrader: (9)

damn treehuggers. mazda should be exempt from this **** because its such a nich engine.

TALAN7

Say they do make it. If it's 2800 lbs, 250 hp is low, especially if torque is low as well. It's going to position the 7/8 the same place as the last RX8 was...much slower than competition. And to me the subaru/scion aren't competitors. They are much cheaper than a new 7/8 would be. I would shoot for 270-300 hp na or make a turbocharged version with 350 hp. Or better yet add some hybrid setup with capacitors or mech flywheel to act as boost. 250 hp with say 30 or 40 more as boost to rear wheels would be nice. The added torque would really help.

My feeling is that Mazda would shoot to position against the subaru/scion, which is a bad idea. The new turbo mustang is going to be hugely popular and tunable. If Hyundai redoes the genesis coupe, I feel it will be a game changer (Hyundai isn't playing). Kia may jump on the bandwagon. Nissan will probably have a new Z that will be lighter and better all around. The new camaro will probably shrink a little. I wouldn't count on it becoming a proper sports coupe. GM is still going to keep it a muscle car.

RIWWP

iTrader: (2)

I don't buy in to the "rotary can't be clean" or "rotary can't be efficient" mindset. Sure, the current iteration is subpar, but to say that it is not possible to achieve is putting on blinders.

I do agree that a rotary is still years away, at the earliest. Mazda has a ton of other stuff on their plate at the moment. However, the ND Miata chassis has already been deemed "scalable for other RWD models", so I believe Mazda still has a rotary in their sights. Why does this help my conviction? Because any other model would either be slightly larger to much larger, and the most powerful engine that they currently produce is still just a 184hp engine, and it already comes in a larger 'sports sedan' (the 6), and the ND Miata will fit the lower slot. Mazda doesn't have room in their lineup for similar-but-different versions of each with skyactive engines. The only 2 differentiating possibilities are either a RWD version of the 6 and a rotary powered sports car.



I've posted this elsewhere before though, on the topic of emissions and efficiency:

There are a host of improvements that are entirely accessible with current technology, and Mazda has already stated in 2012 that they could meet the emissions goals with comparable mileage to piston engines.

For example, any one of these would net an improvement, and ALL are entirely possible:
- Narrower rotors (the 13b configuration has 'wasted space', in that the corners of the flame front don't actually reach the tips of the apex seals)
- longer stroke (for more low end torque / efficiency, allowing lower RPM cruising)
- all aluminum engine (to help cancel the problems of different expansion rates)
- new and improved sealing method Mazda found (to eliminate blow-by of gasses)
- "variable valve timing" (port timing in this case, though it would introduce more parts, it's entirely possible, and is something that the rotary has never yet had)
- direct injection rather than port injection (which has a greater benefit on a rotary than a piston engine, because of the higher fuel condensation rate with rotary port injection vs piston port injection)
- SkyActive tech for higher compression ratios
- laser ignition for more complete combustions
- The newer and better catalytic converter tech that Mazda pioneered that never made it to the RX-8

And this doesn't even take into account anything else Mazda has found and kept quiet on, or any added hybrid tech like iEloop, flywheel based energy storage, etc... (anything that doesn't require lots of extra battery weight, which I'm convinced Mazda would avoid)


You are aware that Mazda has never pursued the power game? Their entire lineup is "slower than the comptetition". Considering Mazda is still setting sales and profit records for the company, I don't think that's as big of a problem as enthusiasts and magazines make it out to be. The next rotary will also be "slower than the competition". You can bet on it!

As far as weight, 2,800lbs would be the weight for a 4-seater rotary, maybe. No way that they would add 600lbs to a 2-seater based on the ND chassis (which is already noted to be hitting the goal of ~2,200lbs).

2,400-2,500 would be far more likely. And considering that I currently drive a 2,490lb ~250hp car, it is plenty plenty fast to have fun with. Hardly something to complain about.

blckninja

iTrader: (1)

I dunno if you looked anywhere or just thought of that on your own but the 16X is supposed to include quite a few of those features. I believe the few improvements that the websites lists are the ones I bolded, I don't think there was anything else.

Also the redesign would increase the engine about 300cc according the website.

Someone posted this earlier, it's listed on their global website. MAZDA:16X | The Rotary Engine

9krpmrx8

iTrader: (46)

I feel like there is an echo in here.