I have read and been told over 100 times that one of the advantages of the rotary engine has always been that it is "very smooth".

Compared to any Honda, Toyota, Nissan Z, Infiniti G35c, even VW's 1.8T engine, do you consider the Renesis as a smooth engine specially at high revs (4000 RPM and up)?

Originally posted by RenesisPower
I have read and been told over 100 times that one of the advantages of the rotary engine has always been that it is "very smooth".

Compared to any Honda, Toyota, Nissan Z, Infiniti G35c, even VW's 1.8T engine, do you consider the Renesis as a smooth engine specially at high revs (4000 RPM and up)?

Why not test drive an RX-8 and see for yourself? I think it's "very smooth", but I have not driven all those other cars you mention.

rx8cited

When I drive, I can rev the car to 7krpm and it feels the same as 4krpm, that's how smooth this rotary engine is. I can't even feel any rough vibrations in the cockpit or chasis. Its just beautiful.

I have owned one since August 03 and have had 16 other cars before this but this is my first rotary.

Speaking exclusively of NVH(noise, vibration, harshness), I find the Renesis noisy and harsh at anything over 4,000 RPM but no vibrations.

One of the European car mags wrote in test driving the RX-8 that"it sounds more like a Japanese bike than a car". I tend to agree with that.

IMHO, the Renesis does not sound refined and smooth but rather noisy and harsh at high revs. Because of the low torque we all know that you have to rev it up to get performance so it adds to the problem.

Anyway, very interest in your comments.

Thanks Skagen.

Maybe I should drive another RX-8 to see if it feels any different, possibly I could have a problem with mine.

the renesis is probably the smoothest revving engine you'll find on the market right now.

the engine sings its beautiful song with no faults or flaws at all.

the only thing smoother than its engine is its margarine slick transmission.

Originally posted by skagen
When I drive, I can rev the car to 7krpm and it feels the same as 4krpm, that's how smooth this rotary engine is. I can't even feel any rough vibrations in the cockpit or chasis. Its just beautiful.

yep the smoothness of the engine is a thing of beauty. and although smooth it does get louder like a swarm of angry bees. it sounds as good as it looks.

its smoother than a babys butt!!!

Actually, I found my self cruising at 7000 RPM the other day and didn't know it. If that helps.

Thanks for all the replies.

What are you comparing the Renesis to ? I know the Honda Accord is not a sports car but it has a very refined, quiet, vibrationless engine at any RPM.

The Renesis on the other hand(at least mine) is very buzzy at over 4K RPM. I can't hear the stereo at 7K RPM.

Originally posted by RenesisPower
Thanks for all the replies.

What are you comparing the Renesis to ? I know the Honda Accord is not a sports car but it has a very refined, quiet, vibrationless engine at any RPM.

The Renesis on the other hand(at least mine) is very buzzy at over 4K RPM. I can't hear the stereo at 7K RPM.

maybe someone put a V8 in it and didn't tell you.

No this aint no V8. Defenitely sounds like a small 4 banger running on 3.

Ic well enjoy your geo metro.

Geo Metro? What does that have to do with this discussion?

My two other cars are German V8s but it would not be fair to compare the Renesis to a 5.0 litre 300+ BHP Mercedes engine, after all this is supposed to be a small sports car.

The most direct competitors to the RX8 are the Nissan Z and Infiniti G35(pretty much the same car) and they are more refined.

I have not driven the Subaru STI or the Mitsu yet so can not make any comparisons.

I drove the G35 4 door, the 350Z and the S2000, the Rx8 is the most refined car/engine of the bunch with the S2000 second. The 350Z's engine while offering alot of low end torque got so buzzy and lost its breath after 4500 RPM.

Well, recalling what Jeremey Clarkson had said in his show: The 8 doesn't seem like running on anything vulgar like diesels or petrols, but on DOUBLE CREAM!

This thread coincides with a question rattling around in my head. Can the Renesis rotors and counterbalances be tuned further, to make it even smoother, say as smooth as a turbine? Does a service like this exist and how much would it cost.

Originally posted by M-ster
Well, recalling what Jeremey Clarkson had said in his show: The 8 doesn't seem like running on anything vulgar like diesels or petrols, but on DOUBLE CREAM!

here are few things he said about the 350Z incase you missed it, lol.


part of the reason nissans Z cars came so fat and so heavy is cause they were designed for the american market and the american car is as you know an enormous sofa. this one wasn't just designed for the americans, it was designed by the americans. to be honest it looks a bit of a mess. but it would cause its a jap car designed in america and the head of a project was an indian and the engine is french. we have had fusion food before, but its the first fusion car. Think of it as being a raw hamburger curry served in a disinterested way in a bed of garlic ajuis. If your the sort of person that likes to cruise the stsreet annoying everyone with the stereo this car is for you.

it doesnt take very long to work out that this car has many weak links and the weakest link of all is the engine. first there is the noise and its just a noise and annoying drone and it gets on yoru nerves. Then there is the perfomance. they say it will do 0 to 60 in six seconds ...but it never feels that fast. when you look at the 350Z you expect it to be light, sporty and agile, but its not. I was expecting it to be like a mx-5 fun...but its not. not even a little.

What it is is a ton and a half of iron mongry. its just a muscle car and muscle cars should be fun but its not. The noise is driving me mad. The hard ride and the effort it takes to drive this car makes it one of the most exhausting cars I have ever come across. The look of the interior is fine, but what is not so good is this (showing the flimpsy build quality) I've seen better build quality in an allotment share. There no practicality. The 350 is a 3 out of 10, it could do better.

Originally posted by zerobanger
I drove the G35 4 door, the 350Z and the S2000, the Rx8 is the most refined car/engine of the bunch with the S2000 second. The 350Z's engine while offering alot of low end torque got so buzzy and lost its breath after 4500 RPM. Well, there you go dude. He just answered your question. I have an Infiniti & I can't bring myself to rev it higher than 4,500 rpm, cuz it starts sounding real disturbed.

Maybe your Mercedes seems smoother. Maybe it's the engine mounts & exhaust system, whatever. Mercedes knows how to appeal to the sensory perceptions & does things to that end. Nothing wrong there, it's Mercedes. They can do those things and people will drool over them and the wealthy will buy them off the showroom floors.

Crap, I've run out of things to say here. I'm not gonna insult your intellegence with obvious jargon. Just what did you expect?

Originally posted by RenesisPower
The Renesis on the other hand(at least mine) is very buzzy at over 4K RPM. I can't hear the stereo at 7K RPM.

Either something is seriously wrong with your engine (doubtful, but possible), or you're confusing sound with vibration. You're talking about the sound at 4K and 7K rpm - that has nothing to do with smoothness! You'd probably say a Ferrari V12 sounds harsh too at 7K rpm, but those are smoother than a V8 too.

Regards,
Gordon

I have owned many cars, and this engine is very smooth, but loud. However that note it makes between 4k-7k is an absloute delight. This is not to say there are not other smooth engines in the market. My previous car was 2002 325i BMW with Dinan intake, & exh., and it probably was as smooth as my engine now, and yes it was also quite. But so is this Renesis.

Mark

yea I'd second the part about it being loud... I sometimes refrain myself from revving it to a normal acceleration from a red light cause all the people around would think I'm launching the car and look at that punk when in fact I'm just revving it to where it normally operates...
but it's smooth as... yea as clarkson said, double cream
one of the reasons why I chose this car is that it's the closest sounding thing to a motorcycle with 4 wheels

Originally posted by mqandil
...However that note it makes between 4k-7k is an absloute delight.
Yep, have to agree 100% with that one, Mark. I just finished my break-in period and am slowly working my way up the rpm range. I had been going easy on it the last few weeks; but the last few days I've started easing toward 7k, and it's amazing to hear what almost equates to a turbine whine (jet type, not turbocharger type) of note to me. Keeping it in a lower gear as I come off a long 270-deg onramp onto the freeway has become downright fun. Amazes me (although I should know better after reading everyone's posts the last couple months) at how much the power really does build in that range. Couldn't do that in my old 3000GT (or maybe it just wasn't as noticeable). Either way - it's absolutely smooth as can be in comparison to my old 3.0L V6. :D

Originally posted by Rotary Titus
yea I'd second the part about it being loud... I sometimes refrain myself from revving it to a normal acceleration from a red light cause all the people around would think I'm launching the car and look at that punk when in fact I'm just revving it to where it normally operates...

Wow. That is so different from my experience.
I find it hard to tell if the car is even ON when it is at idle and the sound when you rev it is so quiet (compared to what with I am familliar) that I think it seems wimpy to anyone that might hear it.

I often find myself cruising along at 6k or so because I forgot to upshift.
Sometimes, I'll go down the road to my office at 7500 or higher in second. Why you might ask?
Why not?
It feels the same as doing it at 3000 in 4th. Purr...

Originally posted by S3/P3/E2
Yep, have to agree 100% with that one, Mark. I just finished my break-in period and am slowly working my way up the rpm range. I had been going easy on it the last few weeks; but the last few days I've started easing toward 7k, and it's amazing to hear what almost equates to a turbine whine (jet type, not turbocharger type) of note to me. Keeping it in a lower gear as I come off a long 270-deg onramp onto the freeway has become downright fun. Amazes me (although I should know better after reading everyone's posts the last couple months) at how much the power really does build in that range. Couldn't do that in my old 3000GT (or maybe it just wasn't as noticeable). Either way - it's absolutely smooth as can be in comparison to my old 3.0L V6. :D

yes low gear, high rev builds that power and then if you suddenly tap the gas pedal(haven't really done a WOT at that point i'm sure it will scream too fast for the traffic patterns i'm usuallyin) it is very responsive. what an engine!

More often than not, the only real stretch of freeway on the way to work is just a short one that usually has a CHP cruiser parked on it somewhere. I've had to make special effort to watch my speed (or at least just play for short stints) because it does climb so quickly. Moving to the east coast in about 2 weeks, so I'll have lots of open interstate (and a Passport 8500) to wind it up a bit.

Smooth is a relative term. After driving my Lexus LS430 for the day and then getting into the RX-8 it feels loud, rough and noisy. But it's a sports car. It's supposed to have some character. If you want quiet and powerful, get a Lexus. If you want something fun and different, drive the RX-8. Or just get both :-)

On order of refined smoothe drive :

Renasis(rotary)
V12
I6
V8

The engine is incredibly smoothe. I sit on motorways at 70 in 6th and press the accelerator - the car just floats quicker, no vibration, no shudder, just whafts its way past 100.

There is noise if your over 5k and pushing it, but the motor and the acceleration is supremly smoothe. I understand this is because it runs on double cream - which I hope is cheaper than the petrol I've been putting in.

You may be confusing 'rev noise' with vibration or 'harshness'.

Noisy it may be, but there is no way it is rough.

On a side note, I have to drive entirely below 5k revs, otherwise I get a high-pitched squealling from the passenger seat.
But if I leave her at home, I can rev to 8500!;)
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doc

Originally posted by Maniac
Wow. That is so different from my experience.
I find it hard to tell if the car is even ON when it is at idle and the sound when you rev it is so quiet (compared to what with I am familliar) that I think it seems wimpy to anyone that might hear it.

I often find myself cruising along at 6k or so because I forgot to upshift.
Sometimes, I'll go down the road to my office at 7500 or higher in second. Why you might ask?
Why not?
It feels the same as doing it at 3000 in 4th. Purr...

Your mpg must be really lousy!

Originally posted by S3/P3/E2
More often than not, the only real stretch of freeway on the way to work is just a short one that usually has a CHP cruiser parked on it somewhere. I've had to make special effort to watch my speed (or at least just play for short stints) because it does climb so quickly. Moving to the east coast in about 2 weeks, so I'll have lots of open interstate (and a Passport 8500) to wind it up a bit.

That's a bummer (the CHP)! Luckily, I live in a nice, rural county with lots of 2-lane twisties and long straightways with narry a law enforcement officer in sight.

The engine is very smooth and the roar above 4k RPM reminds me of an RB211 on a 757 at takeoff power.

Originally posted by S3/P3/E2
More often than not, the only real stretch of freeway on the way to work is just a short one that usually has a CHP cruiser parked on it somewhere. I've had to make special effort to watch my speed (or at least just play for short stints) because it does climb so quickly. Moving to the east coast in about 2 weeks, so I'll have lots of open interstate (and a Passport 8500) to wind it up a bit.

That's a bummer (the CHP)! Luckily, I live in a nice, rural county with lots of 2-lane twisties and long straightways with narry a law enforcement officer in sight.

The engine is very smooth and the roar above 4k RPM reminds me of an RB211 on a 757 at takeoff power. I often leave the radio off so I can hear the rotary hummmmmmmmm!

The only car I have driven that can rev as high as the RX-8 is the S2000. I drove one briefly, and at 8000 rpm it sounds like its engine is about to explode. The RX-8 is not exactly quiet at those sort of revs but is sounds completely unstrained. As someone said, the engine seems as happy at 8000 as at 4000.

Originally posted by Q121825
...The engine is very smooth and the roar above 4k RPM reminds me of an RB211 on a 757 at takeoff power. I'm assuming that's good? ;)
I often leave the radio off so I can hear the rotary hummmmmmmmm! Me too. With the radio on (with audiopilot), I really have to watch the tach. The engine sound is my only other cue for rpm's. And the engine sound, even past redline, is not objectionable at all to me. It sounds very stable and powerful to me, and smooth. Seems like it could go to 12k.

Doc, sounds like you need a muffler for that passenger seat. LOL!

BTW, back in the pre-order days, everyone was down on the car for being too quiet. I guess if you get a 50/50 split on opinions, that means you're right on. I think it is.

By far the smoothest engine I've ever driven. It's whisper quiet and vibration free up to around 4-5K RPM. Past that it starts getting a bit noisy and snarls like a swarm of angry bees near redline, but it never feels harsh or vibration-prone. When idling, it's difficult to tell the engine is even running.

I occasionally find myself at 6K+ RPM in 3rd on the highway because the car is so smooth I just forget to upshift. The car is practically inaudible under 3K RPMs, and new drivers to the car may find themselves stalling when launching because they can't hear the engine over the stereo.

If you saw C & D's review last year when the guy tested the car he said something to the effect of..

"There is an audible tone to tell you to shift at 8500 rpm, because you would not know it otherwise. There is no humming, vibration, or anything to indicate you are at redline".

Not an exact quote but close. For anyone that wants to distinguise noise from smoothness take the car in 3rd gear on the highway and go to 7500 RPM and let off the gas and let it coast, turn the stereo off.

Originally posted by hotpot
Your mpg must be really lousy!

Yeah, pretty horrible. 13 - 15 MPG at best.
Oh well...:p

You have to consider what kind of speeds the engine is spinning at when you are at higher RPM. A smooth running engine is a sign of how good the rotary is. The noise has more to do with the RX8 being a sports car than it being an inherently loud. Comparing it to other luxury cars is unfair because they have much more sound insulation, but more sound insulation equals more weight. And since the RX8 is a sports car that’s means less sound insulation.
If you put the rotary in something like a Lexus, than it would probably be almost silent.

Guys,

Thanks for the comments. I agree with the large majority re the smoothness of the Renesis.

This is no Lexus luxury car so the engine noise is expected in a sports car like this. I sense no vibration or harshness above 4K RPM but was concerned about noise and sounds like that is normal.

I will continue to enjoy my RX8 and thanks again for all the feedback.

Originally posted by RenesisPower
No this aint no V8. Defenitely sounds like a small 4 banger running on 3.

Have you purchased a KLEGGSPEED mod? When zapped, the little rodents do scream in a harsh manner...

I have and Klegg is right. Do a search you will discover the beauty of vermin power.

Originally posted by Rotary Titus
it's the closest sounding thing to a motorcycle with 4 wheels

So true!

Originally posted by 93rdcurrent
I have and Klegg is right. Do a search you will discover the beauty of vermin power.

Ah, a happy kleggspeed customer..:)

Originally posted by Maniac
Yeah, pretty horrible. 13 - 15 MPG at best.
Oh well...:p

You're probably used to driving an auto-box; Or you own a gas station.

I can't believe you're driving around at 7500 rpm in 2nd gear and not be bothered by the noise.
The engine is indeed very smooth but when you get in the higher revs, it gets very loud. I heard the 8500K rpm warning beep for the first time last night and I needed to listen hard for it to hear it.

Originally posted by hotpot
You're probably used to driving an auto-box; Or you own a gas station.

I can't believe you're driving around at 7500 rpm in 2nd gear and not be bothered by the noise.
The engine is indeed very smooth but when you get in the higher revs, it gets very loud. I heard the 8500K rpm warning beep for the first time last night and I needed to listen hard for it to hear it.

No, I've never owned an auto trans and my mileage only goes up 1 MPG if I baby it, so why bother.

I wonder if there is really that much tolerance in the manufacturing of the RX-8 to account for all of the different opinions on the noise level of the Renesis.
My shift beeper is clearly heard over the motor when accelerating.
When cruising, in ANY gear at ANY RPM, the motor makes almost no noise at all.

Originally posted by hotpot

I can't believe you're driving around at 7500 rpm in 2nd gear and not be bothered by the noise.


I did this a couple of times when I first got the car- forgot I was in second, and drove to the gym from work. Never noticed, since the radio was on and effectively drowned out the noise.

Originally posted by RenesisPower
The Renesis on the other hand(at least mine) is very buzzy at over 4K RPM. I can't hear the stereo at 7K RPM.

So turn it up! ;)

This engine is not harsh/buzzy at all. If anyone has driven a Kia or Hyundai V6 over 4k RPMs (if it even goes that high), you'll know harsh. The engine sounds like it's ready to fall to pieces. The RX8 is loud at upper RPMs, but definetly not harsh. Very smooth, sweet and great sounding! Nothing like hearing a beautiful engine sing its song when your mashing the pedal!! My favorite part is how smooth it is at idle. My 1.8t engine in my Golf vibrated really bad at idle, the RX is so smooth. LOVE IT!

Can't resist joining in this one! DrComputer is right, if you want smooth get a Lexus. My SAAB 9k CSE AT turbo is smooooth, with 2 balance shafts and max torque coming in at 1900 the effortless top gear surge from 40 to 80 was so satisfying, but it never left me grinning ear-to-ear like the first time (and every subsequent time) I drove the RX8.
The RX8 may be smooth in some respects but that's not the reason we drive them. It's "joie-de-vivre", "elan", "esprit". Mazda has once again out-Lotused Lotus.

I have to agree on this one. I often find myself turning the stereo down to get a better "feel" of the engine. One things for sure, each time I see a RX8 comercial on TV I surprise myself thinking "Damn, that's a sweet car" before realising it's mine. Granted I don't have 2k miles on it but still :)

Well, recalling what Jeremey Clarkson had said in his show: The 8 doesn't seem like running on anything vulgar like diesels or petrols, but on DOUBLE CREAM!
Yes... one of my favorite JC quotes from one of my favorite TG reviews :)

Along with... "Oh My!" "Wow!" "Hah!" "yes..Yes..YES!" and "This (the '8') is the easist car to drive fast that I have ever driven" :D

Extremely enthusiastic about the '8'... all in all.. Said "I think this is the best car I have driven all year" (and then later said.. well maybe..) though he didn't really care for the styling and he expressed a concern about the performance of the tires in the wet. ... which he later retracted on a UK radio show, after trying out a different set of tires.. and then went on to say on the same radio show... "For the money, and even for two..even five or seven thousand pounds more... there is simply nothing better on the market".

Go.. JC.. Go!

Smooth. Yes. 4 moving parts. Sounds like ripping silk.

at 9k rpms, the rotors themselves are spinning at 3k rpms. compared to a piston, at 9k rpms, you will have less vibration on the engine :)

I can't believe no one has touched on the real forces at issue here.

The answer to the question of whether the RX-8 rotary is a smooth ENGINE is YES. It is smoother than ANY piston/crank that exists. The closest engine I have experienced is the Subaru opposed 4.

I will now take you beyond opinion statements to scientific evidence...

Piston/crank engines (from here on called PC engines) have reciprocating mass; pistons that move in one direction stop and then move in the exact oposite direction. Imagine a single, vertical, piston for a moment. As the Piston accelerates down, momentum is created and is transfered through the engine. The piston slowly returns to TDC (2x) then is accelerated again. Each time the ignition fires you will feel a jolt through the entire system as moment is created and lost (through friction).

The easiest way to combat this system is to place a second piston attached to the same crank in exactly the oposite direction (horizontally opposed or vertically opposed). Time each piston to fire at exactly the same time and the forces created by the sudden acceleration and deceleration of each piston will be perfectly countered and cancel eachother out (in a perfect controlled environment). The Subaru engine uses this setup to achieve a smooth engine, as well as lower the center of gravity for better handling.

In a "V" configuration (V6, V8 etc...) it is impossible to eliminate vibration due to the direction the forces travel. Most engines of this configuration contain "counterbalancers" attached the crank to try and cancel the forces somewhat. Ask a Harley Davidson owner how well they work though. This also robs the motor of power by increasing the weight and Moment of Inertia of the crankshaft.

Inline 4s do a pretty good job at smoothness due to their even firing order (Piston movement is always well spaced to naturally cancel other piston's force created by acceleration). However, the forces of the downward piston are greater than the upward piston due to the direct force applied to the downward piston (combustion) which will create some vibe.

In any of these situations, if one piston is slightly heavier (even imperceptibly) due to the fact that perfection in milling cannot be attained, that will create a force imbalance and vibration.

In addition to the pistons causing vibe, the valvetrain is fully of parts banging around, up and down, back and forth, with chains that rub (tensioners) and all of that will add to vibration.

Rotary engines DO NOT HAVE reciprocating parts or valve trains. :)
This is precicely what makes the 8 special. Combustion also occurs much more fluidly as the time between combustion events of 1 rotar is 1/6 that of a single piston (in terms of crank rotation). A 2 rotar engine is like having a V12!!! (in terms of power deliver timing). All of this without a valve train or a single opposed force.

You don't even have to drive an RX-8 to KNOW that it has a smoother ENGINE than ANY piston/crank driven automobile (this is not a matter of opinion or seat of the pants "feel"). :cool:

This is not to say that the ride is smoother or the engine is quiet. All this means is that there are virtually no vibrations sent from the engine into the chassis.

On a side note, I have to drive entirely below 5k revs, otherwise I get a high-pitched squealling from the passenger seat.
But if I leave her at home, I can rev to 8500!;)
Thanks Doc.. You got a good old fashion belly laugh out of me and the wife for that one!

:)

I have to agree on this one. I often find myself turning the stereo down to get a better "feel" of the engine. One things for sure, each time I see a RX8 comercial on TV I surprise myself thinking "Damn, that's a sweet car" before realising it's mine. Granted I don't have 2k miles on it but still :)Your RX8 has a radio? Hmmmm, lemme go check this out... :confused:

:cool:

It's true. The drivetrain seems to be totally isolated from the car. If there is engine vibration, it does not get through to the steering wheel, the pedals, chassis. The only perceptible vibration can be felt through the shifter knob, but it is part of the powertrain.

sit at 80mph in 6th and depress the accelerator fully - on a decent flat road. You start at 4000rpm.

The car just glides. Not quickly(as your in 6th) but it just goes faster with no vibration or hastle. THATS what shows its smothe.

Its also a sports car and performance engine so will sound loud and noisy - it has to brethe. Dont mistake sound for smotheness.

attesting to the smoothness of the engine, i was driving home from south beach last weekend up highway 75. I had the car in 6th gear and was just constantly accelerating but not looking down at the speedo. When flew up on a car that seemed like it was not moving at all i looked at the speedo and i was doing 123. I could not believe. Except for the idle, which i still have yet to get the "M" flash just becuase I am to lazy which would probably fix the problem, this engine is smoother at high RPM's than any other car that I have ever driven

I don't usually have the radio on, but I once had it up loud and didn't know I was close to redlining it in 3rd gear. The car does make noise, but if you eliminate that, you really can't tell if it's high or low in rpms.

If that isn't smooth, I don't know what is.

Can't comment on many of the cars questioned, but I just traded in a 2003 VW Jetta with the 1.8T. Jetta was a great car. RX-8 is superior in so many areas, I don't know where to begin. Mostly, the "fun" factor is much greater with the RX-8. I'm finding fuel consumption, performance, etc. to be neck-and-neck.
IMHO>Tony

Good God people do some learning, and searching, and reading about engine designs and their inherent balance and/or lack there of. To start with, a rotary is fundamentally balanced and an inline four is not. Period. No matter how hard Honda or anybody else tries, an inline four is going to be a harsher feeling and sounding engine than a rotary. Or, an inline six or V12...

The smoothest engines have perfect primary balance: sixes, inline and flat, and their variants: vee and flat twelves. Inline fours are fundamentally unbalanced - it takes a balance shaft, or two, to smooth them out. V6's? Unbalanced. You have to offset the crankshaft angles to get something approaching smoothness. The only inline fours I've driven that felt reasonably smooth are the counter balanced ones, like the Porsche 944. V8's can be designed to be relatively smooth, but they are not fundamentally balanced. They usually have a harmonic balancer or other device added on to smooth them out.

Do some research and learn about how firing order and crank throws affect smoothness and "balance". It's great reading, and you'll understand more about engine design.

The rotary is extremely smooth as its two rotors balance each other out pretty well. I'd put in it the same league as a well designed and built inline six. Yes, I'm extremely biased towards inline sixes because they're simple and elegant, and you can design them with a really even power band. And, they sound fantastic. The only criticisms of inline sixes and V12's is that they require a pretty beefy crankshaft since the shaft is relatively long, and the length of an inline six (and V12 for that matter) engine means the car will have a somewhat long hood. Hey, is there anyone who doesn't like a car with a long hood? Many of the world's classic cars have long hoods.

My only subjective criticism of the rotary: its song isn't very interesting because there's not much complexity in its tone. After all, there're only two rotors and an eccentric shaft moving around. Still, it sound's pretty cool. But, in an inline six, you've got a bunch of stuff moving around, six cylinders worth of pistons, rods, and valve gear, and it goes around in a really pleasing way. It's been characterized as sounding like "ripping canvas".

Don't get me wrong; I really like the rotor motor. I just like an inline six more. But, RX-8's don't come with inline sixes. In fact, only BWW and Lexus offer them in cars I would be interested in, and I didn't want to spend for those cars and my '94 325is was getting a little long in the tooth. The RX-8 is unlike any car that BMW and Lexus make. I think the rotary sounds best constantly winding up through the gears. At steady state throttle, I'll take a multivalve inline six over everything else except a V12... V8's? Had 'em, love 'em, but sixes and twelves sound more complex and sophisticated. The rotary is somewhere in between.

Road and Track had a great article within the last few years about what exactly makes an engine sound good. It has to do, interestingly, with the same principles that apply to music; fundamental frequencies mixed with certain kinds of overtones (harmonics), sound pleasing to the ear. Inline sixes and V12's produce better sounding overtones, in addition to their fundamental sounds.....

You may be confusing 'rev noise' with vibration or 'harshness'.

Noisy it may be, but there is no way it is rough.

On a side note, I have to drive entirely below 5k revs, otherwise I get a high-pitched squealling from the passenger seat.
But if I leave her at home, I can rev to 8500!;)
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doc

Great post, LOL. I totally agree, the 8 is a one person car to enjoy, or you must have the right passengers. My 16 yo and 5 yo love to drive with me. My better
half and my 8yo complain. I think it depends on if you like rollar coasters or not. i.e., enjoys g-forces or get sick under abnormal Gs.

If you want to compare hp vs smoothness, I have never driven a car that is more smooth. If you want pure smooth, drive a sohc 100hp car like my 95 golf, and you get really smooth, even more so then my rx8, but just no power. Once I get my car going past 4k rpms, I do feel the hp kick in, so in my point ot view it's not a pure straight up dead even power curve, but it is certainly quite a smooth running engine. It's also deceiving, because the car doesn't feel as fast as it is. With the smoothness of the renesis, comes lack of power compared to cars like the g35, 350z, and of course turbo charged cars. The mazdaspeed rx8, if it comes out in US will certainly lose the feeling, and will give you a hard kick, unlike it does now. Personally though, for daily driving, the rx8 as it is is a fun car to drive, and great for all around performance and daily driving. I'm still getting used to it myself, but I wouldn't mind a s/c in this car, so you can still get the same feel at lower rpms until you want car to take off and pull you back in your seat.

On a side note, I have to drive entirely below 5k revs, otherwise I get a high-pitched squealling from the passenger seat.
But if I leave her at home, I can rev to 8500!;)
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doc
LOL!!!:D :D :D

I know the feeling

Here's a vid of my wife taking off, shifting at 7500RPM...

Get an idea of how it sounds from the outside.

I love it.

The car is bone-stock, btw.


http://home.comcast.net/~noel16valver/MOV00277.MPG

HMM... Is it just me or it seems like this "RenesisPower" character is just toying with the very basic Idea of a R-Engine? Of course it's smooth! It's a rotary for god-sake. Maybe you don't even own one at all "R.P" :mad:

BasenjiGuy, since you do so much reading you must know that the vibration perceived by the car's occupant may start with the engine characteristics but has much to do with the way the motor is mounted and the structural stiffness of the body.
There is eccentricity in the rotor movement, and while the pairing of the rotors may cancel the lateral forces, I think a slight sideways rotational wiggle (about the vertical axis) gets through. You can feel this in the shifter at some engine speeds and loads.
The very light motor and very stiff body structure may have as much to do with the perceived smoothness of the car as the inherent balance/imbalance characteristics of the Wankel.

I routinely forget that I'm running in 4th gear at 65-75 MPH if that gives you any indication. Every other manual vehicle I've ever had was BEGGING to be shifted well before that point. It has a rev linearity like a street bike and as someone put it, it's smooth as a baby's a$$. I drove the G35 sedan, the 350Z, the S2000, and my wife has an Accord V6 (240 hp). The G35 sedan and the Accord are smoother, but they should be....they're family sedans. The S2000 was too buzzy and it felt like I had to run it to redline to get any power out of it. Despite it being faster according to the car mags, it doesn't feel faster to me. The 350 did feel faster because of the torque, but the suspension made me bleed from my kidneys after a short drive. You'll feel every bump in the Z, but it has impressive acceleration. I got a little off subject, but that's my $.02.

Osisris,

As said before I have owned an RX-8 since last August. I guess the issue of smoothness is relative to what you are used to. Most of my previous cars have been big German V8s so compared to the 8 they are much smoother at any RPM.

This is my first rotary and in particular 1st gear over 6K RPM does not seem smooth to me, it is rather loud albeit vibration free.

I think we need to define smoothness. Because noise does not equal smoothness.

Naturally the car is louder, you're doing WOT and reving it up to 9k rpm!

It's still smooth even at redline.

I think we need to define smoothness. Because noise does not equal smoothness.

Naturally the car is louder, you're doing WOT and reving it up to 9k rpm!

It's still smooth even at redline.

EXACTLY! Thank you! 'Nuff said...