Why Do Rotaries Suck?

[martyt]

so more lies from jase.

his quote say 12.4L but look at the link

etrol 98RON 12.4 18.3 9.1

12.4 is combined .

CITY DRIVING IS 18.3.!!!! YES comapred to a rotary @13L

Highway cruising in an R35......expect 9.1L /100KM ROFL

1) insults becos your a B.S. Talker who is trying to F##k the whole argument with made up nonsense bcos you are a one eyed skyline fan.

2) your car will not get 10-11L, are you a c..k smoker? a 2L inline 4 SR20DET will get 10L and you believe you can match that with 50% MORE cylinders + 25% more capacity?

3) the fuel consumption is calculated by running the engines in real time and under different loads. The loads are there to simulate the city driving and the highway drving. these are done to official standards

QUOTE:Australian vehicle emission standards largely reflect international standards developed by the United Nations. These standards are adopted in Europe and many other countries around the world, and are known as the "Euro" standards.

thats what the website says.

Please provide proof of this"granny driver" . Because its all lab tested figures.

And for the record. I'm not having a go at you or anyone else. It is just that figures dont lie. The 13B has similar fuel consumption to other engines. Fuel consumption is directly related to how much fuel your inctors can flow in any given minuite. and no one said you had to slam the pedal ALL the time, bad fuel consumption may be the reult of bad driving habits. The one point that is obvious is the fuel usage at low "revs" (real or fake or whatever is in dispute) is higher than a similar power out put piston engine. Just remember the race track / open road is not stop start traffic.

[jase-r34]

I clearly stated COMBINED fuel consumption in my above post if you could read. Apparently you can't.

I would have stated city/highway/combined but the figures were unavailable for the rotary.

It's a government website, just like you used.

More personal insults? Keep em coming keyboard warrior!

Oh and I DO get 10-11 L/100km. Last I checked doing 500km and putting 50 litres of fuel in the car is 10L/100km. Maybe your calculator says different to my apparently terrible maths?

I'm not a one eyed skyline fan thanks, I actually prefer my bike to my car, and it's a honda. I love all kinds of cars including the later model RX-7's. I don't even have a problem with the rotary engine either, just the god damned awful noise it makes. But that is personal opinion.

the FD has a 13B twin, which uses only slightly more fuel but makes almost double the power.

So they came with nearly 340kw then? Sweet.

[martyt]

once again i will keep the insults going if you dont start to comprehend what the fuel consumption argument is about.

The R35 uses more fuel in all aspects, city, highway, combined. compared to the rx7.

You say it makes more power. Woah man thats some magical trick there, Larger displacement (currently being debated), Larger turbochargers, more boost, more fuel consumption. If the R35 made less power than an FD i would be extremelly dissapointed.

but i digress, no one here belives those figures are trully representative of how a car is driven "spiritedly"

The point, let me emphasise, is that the fuel consumption is not markedly worse than a V8, show me reputable figures for your car (conveniently not listed) and have a look at its consumtion against 4 cylinder turbo cars. Note a large difference in city driving but similar consumption in highway?

and no one gives a $hit what km/L you get on your dreamer home calculator. This is the part where you look stupid.

"but i do get 10L/100km"

i can go and say i get 5L/100km on an rx7.

the point you have forgotten is your not comparing apples and apples. drive your car like a baby? do the same for a rx7 and i guarantee the consumption will be less than 13L/km

The fact is that both the skyline and rx7 could not meet the strict euro emmisions regime and consumed similar amount of fuel.

MAIN POINT: no one goes "GTR's use insane amounts of fuel" or "a 6L V8 uses insane amounts of fuel" which is in the same league for stock cars. but you guys say it for rotary's.

[jase-r34]

I don't understand your personal insults as I never said anything along the lines of a rotary being a fuel guzzling monster. I just quoted figures from a government website like you did. Period.

i can go and say i get 5L/100km on an rx7

You can say it, but you'd be lying. I am not. Like I said, believe what you want. I don't drive it like a baby, I just don't thrash the shit out of it.

Figures for it will be useless as my car is no longer running the factory ecu. So I'm not sure what it is you are looking for there.

do the same for a rx7 and i guarantee the consumption will be less than 13L/km

Shit hey 13L/km. That's awesome. LOL sorry couldn't help myself, with all the insults being thrown at me n all.

[ylwgtr2]

fknell.....dunno about you guys....but if i wanted fuel consumption....id buy a prius

[Shiraz200SX]

fknell.....dunno about you guys....but if i wanted fuel consumption....id buy a prius

and add the vagina that comes with owning a prius....

[jase-r34]

Lol true that ^^

[scathing]

Argument 1 : They are inefficient. Most people assume efficiency though use of fuel = petrol. But this is just wrong.

How is that wrong? Do rotaries not use petrol for fuel?

everyone says " thats a lot of fuel to use for a 1.3 litre engine" assuming that its a cylinder engine. the 1.3 litre capacity means very different things in the 2 completely different engine types.

OK, lets take displacement out of the equation. Also, for fairness, we'll remove forced induction out of the loop so we don't get the usual "its easy to just wind on more boost" arguments when people compare FI engines on numbers alone....which I noticed you started using when comparing against the R35 GT-R.

A stock RENESIS engine (Mazda's latest-and-greatest whizz-bang rotary) doesn't make that much fuel for the power it generates. Its power and torque figures are basically bang-on with Honda's F20C, but needs a lot more fuel to do it. The F20C isn't particularly big or heavy either, if your unit of efficiency relates to the powerplant's volume to power output.

Are you going to start accusing SAU people of being Honda fanboys now? That'll be as hilarious as the guy who said we were all Commodore fans on here.

In the real world when the RX-8 was compared to the 350Z (its closest competitor) on road loops by car mags, the V6 pushing an extra 100kg manages to use less fuel to travel the same distance at approximately the same pace.

By any objective measure rotaries are fuel inefficient. Off-boost they're "not bad", but with their inherently low compression ratio they're not extracting as much power out of the petrol injected as they could be compared to a small piston engine generating a similar amount of power.

Argument 2 : They are unreliable. What is actually unreliable about an engine that if you maintain as per the manufacturer's instructions, will last as long as the manufacturer's stipulated warranty?

Your expectations must be set extremely low if you think that a stock engine not grenading itself within 3 years can be deemed as "reliable". Or even 8 years, if you take Mazda USA's revised RX8 warranty. Even Fords/Holdens, whos production lines seem to have the loosest tolerances this side of a nymphomaniac hippie, generally stay together for longer than that if you treat them the way the manufacturer recommended.

[ylwgtr2]

and add the vagina that comes with owning a prius....

Ah yes...but imagine the vagina id have with all that saving $$$ on fuel huh???

[nisskid]

Imagine if they just kept adding rotors till the engine was the same weight as an LS9, I have no idea how long or feasible this would be, but why not?

i remember a while back someone compared the weights of a few engines (LS1, 13B and SR20) and the LS1 wasnt that far off the weight of the rotary (including all engine components, not just the block) due to it's alloy construction, not that LS1's are that much less fragile lol

not sure how true that is.

[aidannn]

I never knew my RX7 was a 3.9 litre elliptical engine produced 230rwkw at 3,000rpm. first turbo must be kicking in at 800rpm and second one at 1800rpm holding strong to the 3,000 range. I like engines. I like my RX7s 13BTT, I like the SR20 in my silvia and I love the RB26s in my GTR. hey the VR38TT in my R35 was pretty kick ass too. getting an EP3 civic type R soon and I love the 2litre 4 pot in them too. I guess I just like engines. they all have their strong and weak points.

my 13b would possibly break if I look at it the wrong way. so will my RB26.

the SR20 don't like too much revs and may decide to break rocker arms just to piss me off.

the 13b and the RB26 drinks fuel like it's zohan drinking a fizzy bubbler

the NA EP3s motor lacks that fat midrange my turbocharged motors have.

the VR38 is just too good at what it does and in some ways that's depressing too.

I quite like the whateverthefk engine is in my nissan atlas truck too. it makes a massive 98kw but has some giant torque figure and for it's purpose it's perfect. and it's a 4.2l 4 cylinder and it has a redline of about 3,000 too. don't think it works the same as a 3.9l 3,000rpm rotor though....

you have an epic garage.

[Birds]

Ok Gary,

Firstly engine RPM is exactly that, the amount of revs per minute the engine is outputting... Not the piston strokes or rotor cycles, you can't say that a rotor's rpm is what is takes for one rotation of the rotor, otherwise you would have to judge a piston engine on piston speed and then the RPM of a 2-stroke would only be half the speed of a 4-stroke!!! But they are not, the engine RPM is based on crank speed.

It's not a 2-stroke, its not a 4-stroke... It's a rotary!!! Granted it's got more in common to a 2-stroke engine, but it's not because it does not have pistons... therefore it doesn't have a piston stroke.

I'm sorry but your a little wrong with your displacement comparison as well. You can not compare them as they are not the same, a piston engine does not carry potenial energy of more than one combustion cycle in a single cylnder, but a rotary engine carrys not only one combustion process but the potential energy of 2 other combustion processes.

It can't be compared to a 1.3L piston engine as much as it can't be compared with a 3.9L. It's a 1.3L engine per combustion process with 2.6L of potential energy in reserve, a piston engine is a 1.3L per combustion process with no potential energy in reserve!!!

Cheers

Simon

Don't waste your time trying to tell this tale of simple logic! You'll end up like me, several pages later and still arguing the same points with him! But it's good to have you on board

Your expectations must be set extremely low if you think that a stock engine not grenading itself within 3 years can be deemed as "reliable". Or even 8 years, if you take Mazda USA's revised RX8 warranty. Even Fords/Holdens, whos production lines seem to have the loosest tolerances this side of a nymphomaniac hippie, generally stay together for longer than that if you treat them the way the manufacturer recommended.

Who needs engine tolerances when you have 8 pistons to keep the engine going...that's 8 lives right there

I agree completely. Most consumers do expect the car to last past warranty...otherwise the second hand market would be worthless. This thread has been several different debates so I might as well throw the muscle cars vs rest of the world debate in there too haha. Aussie/American engines are some of the toughest out there...they can go for much longer being treated like shit, and they do. I can't deny all 427,000km on my piece of shit Windsor 302 and still counting. That's low mileage too

[bozodos]

Rb30s are stronger than local motors - 500 000km on an unopened RB30S FTW

[Sydneykid]

Ok Gary,

Firstly engine RPM is exactly that, the amount of revs per minute the engine is outputting... Not the piston strokes or rotor cycles, you can't say that a rotor's rpm is what is takes for one rotation of the rotor, otherwise you would have to judge a piston engine on piston speed and then the RPM of a 2-stroke would only be half the speed of a 4-stroke!!! But they are not, the engine RPM is based on crank speed.

You may need to go back and read what I actually wrote not what you think I wrote. The undeniable fact is the rotors only do 3,000 rpm, in terms of combustion (in a combustion engine) that's somewhat important. The gear up ratio of the eccentric shaft is irrelevant, I go to the original point, a rotary engine could have any multiple of 3 in its gear up ratio. Let's say 6, so the eccentric shaft would do 18,000 rpm but the rotors would only be doing 3,000 rpm. The gearing is irrelevant, the rotors are still only doinf 3,000 rpm. That’s the combustion process rpm of the engine.

When the rotor supporters do a comparison they claim 9,000 rpm compared to a piston engine. But the truth is the pistons in a piston engine (again the all important combustion process) actually cycle at 9,000 cycles per minute, whereas the rotors only cycle at 3,000 cycles per minute. So it’s an important fact in any comparison that it is pointed out that 9,000 rotary rpm is not the same as 9,000 piston rpm.

Of course I have no need for such comparisons, I know full well that the rotors only do 3,000 rpm, so they really are a low reving combustion engine.

It's not a 2-stroke, its not a 4-stroke... It's a rotary!!! Granted it's got more in common to a 2-stroke engine, but it's not because it does not have pistons... therefore it doesn't have a piston stroke.

You would have already noted this if you had actually read what I wrote, in the context of combustion engines stroke and cycle are synonymous, check your dictionary.

I'm sorry but your a little wrong with your displacement comparison as well. You can not compare them as they are not the same, a piston engine does not carry potenial energy of more than one combustion cycle in a single cylnder, but a rotary engine carrys not only one combustion process but the potential energy of 2 other combustion processes.

Sorry, when 1 cylinder in a 6 cylinder engine is combusting it's carrying the load of the other 5. Much the same as when one side of the rotor is combsuting the other 5 are being caried. I fail to see the difference.

It can't be compared to a 1.3L piston engine as much as it can't be compared with a 3.9L. It's a 1.3L engine per combustion process with 2.6L of potential energy in reserve, a piston engine is a 1.3L per combustion process with no potential energy in reserve!!!

I'm not comparing, you need to read what I post more carefully. Let me spell it out for you, a 13B is a 3.9 litre, 2 stoke/cycle rotary engine with rotors that only rev to 3,000 rpm. I don't add any the comparison to that, it is what it is.

Cheers

Gary

[910trx]

and add the vagina that comes with owning a prius....

straight to the organic markets to buy a cucumber LOL

[pixel8r]

2) your car will not get 10-11L, are you a c..k smoker? a 2L inline 4 SR20DET will get 10L and you believe you can match that with 50% MORE cylinders + 25% more capacity?

Its entirely possible to get 10-11L/100km city driving in an R34. I used to get that when I had my series 2 stagea (same engine as R34). It also had 160kw at all 4 wheels at the time. Modified doesn't necessarily mean more fuel. My fuel consumption went DOWN the more mods I did. All of the mods were either helping it breathe better or making the tuning more efficient. More power AND better fuel economy.

Comparing (a R34) to a SR20DET isn't a good comparison. I've owned one in a S13 and whilst it was a fast car it wasn't great on fuel. Great engine in their day but average by today's standards. My current stagea gets better fuel economy than the SR20DET and that is with a VQ25DET (206+kw and 407N-m) - so yes 50% more cylinders and 25% more capacity, and yet 34% more power and 46% more torque, not to mention an extra 500+kg worth of car to haul around.

There are a lot more factors to fuel economy than just the size/capacity of the engine.

sorry for getting offtopic though...

such an interesting thread. and generally speaking (this is not aimed at anyone in particular), resorting to insults is an admission that you lost. Its interesting to see who is able to argue objectively and who resorts to personal attacks. "Arguing" is a skill that takes years to master And it can (and should) remain civil at all times. Criticise what the person said, not the person themselves

[Birds]

You know I used to agree with you Steve, but these days I can see why some people turn to insults because of frustration, not always because they don't have any argument left in them. When you argue with the same person over and over and nothing is getting resolved or agreed upon...sometimes you can't help but want to call them a dickhead. I avoid insults where I can myself...but I can certainly see how others lose it!

P.S. I also realise the irony that I am in fact arguing about arguing.

[SimonR32]

You may need to go back and read what I actually wrote not what you think I wrote. The undeniable fact is the rotors only do 3,000 rpm, in terms of combustion (in a combustion engine) that's somewhat important. The gear up ratio of the eccentric shaft is irrelevant, I go to the original point, a rotary engine could have any multiple of 3 in its gear up ratio. Let's say 6, so the eccentric shaft would do 18,000 rpm but the rotors would only be doing 3,000 rpm. The gearing is irrelevant, the rotors are still only doinf 3,000 rpm. That’s the combustion process rpm of the engine.

When the rotor supporters do a comparison they claim 9,000 rpm compared to a piston engine. But the truth is the pistons in a piston engine (again the all important combustion process) actually cycle at 9,000 cycles per minute, whereas the rotors only cycle at 3,000 cycles per minute. So it’s an important fact in any comparison that it is pointed out that 9,000 rotary rpm is not the same as 9,000 piston rpm.

Of course I have no need for such comparisons, I know full well that the rotors only do 3,000 rpm, so they really are a low reving combustion engine.

You would have already noted this if you had actually read what I wrote, in the context of combustion engines stroke and cycle are synonymous, check your dictionary.

Sorry, when 1 cylinder in a 6 cylinder engine is combusting it's carrying the load of the other 5. Much the same as when one side of the rotor is combsuting the other 5 are being caried. I fail to see the difference.

I'm not comparing, you need to read what I post more carefully. Let me spell it out for you, a 13B is a 3.9 litre, 2 stoke/cycle rotary engine with rotors that only rev to 3,000 rpm. I don't add any the comparison to that, it is what it is.

Cheers

Gary

It's ENGINE RPM!!! Not rotor RPM, you measure horsepower, torque and RPM at the flywheel, not at the piston or rotor!!!

Dictionary check

"An internal combustion engine cycle completed in two strokes of the piston."

"denoting an internal combustion engine whose power cycle is completed in one up-and-down movement of the piston."

"designating or having to do with an internal-combustion engine in which a complete fuel cycle in a cylinder requires only two piston strokes"

"A two-stroke engine provides power on every other stroke of the piston. It is the most common and affordable type of engine."

I can keep going, but I don't have the time...

And you fail to see the difference in potential energy... Try breaking it down into a single rotor engine vs a single piston 4-stroke engine to make it nice and simple for you, when the single piston engine finishes its combustion cycle it has no more potential energy stored, when a single rotor completes a combustion cycle it has two more combustion cycles in progress, hence still having potential energy!!!

I totally agree with you they should not be classed as a 1.3L 4-stoke engine because they are not... But they are not a 3.9L 2-stroke with 3000rpm on tap!!!

[BoyWhoCriedWolf]

Well, this is pretty dissapointing I must say. 15 pages of fkn inane natter and not one picture of:

Cake

Matured cheese

Boobs

Pick your game up kunce.

Thanks for listening,

Ken

[mad082]

this thread at the start........

this thread now.......

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