| kirk |
just curious. it seems like i never get it over 3k rpm's on the highway. even when i punch it, it RARELY gets over 4k. who out there has gotten the thing to redline and what were the circumstances?
kirk |
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| dmako |
A guess but try dropping it into L)ow.
quote:
Originally posted by kirk
just curious. it seems like i never get it over 3k rpm's on the highway. even when i punch it, it RARELY gets over 4k. who out there has gotten the thing to redline and what were the circumstances?
kirk
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| special-k |
quote:
Originally posted by kirk
just curious. it seems like i never get it over 3k rpm's on the highway. even when i punch it, it RARELY gets over 4k. who out there has gotten the thing to redline and what were the circumstances?
kirk
Perhaps my CVT is malfunctioning but if I mash the pedal on the freeway (cruising at 70-80mph) it usually gets up damn close to redline. |
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| Stoker |
quote:
Originally posted by kirk
just curious. it seems like i never get it over 3k rpm's on the highway. even when i punch it, it RARELY gets over 4k. who out there has gotten the thing to redline and what were the circumstances?
kirk
I don't think to many people redline their Mo's for very long if ever. One sure thing that will happen is that your fuel economy will go into the toilet.
My training as an engineer always wants to ensure that I do not over extend the engine so that it last a long time. |
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| kirk |
i'm going to try mashing mine on my way home and see what happens...
it just seems like a low rpm running car - nice, smooth and quiet. |
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| hfelknor |
And my training as a technician makes me want to test it every now and then, to see that it will indeed meet engineering's specs. :D
Although I only do it maybe once or twice a month (A lot less now than about $1.50 ago), I do it in DS and accelerate for 5 to 10 secs.
This could mean from 30 to 80 MPH or from 65 to 100MPH or so. Once it is there, I don't leave it there very long.
Homer |
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| Eric L. |
| In your average car, you can get it pretty near redline without flooring the pedal (say 3/4 throttle). With the MO, you need to bury your foot to the floor, and the CVT will kick it up a few gear ratios and send you screaming towards redline. |
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| Corin |
I've hit redline a few times. In normal D mode it takes a while before it jumps up there, but if you drop it into S it will get there pretty quickly.
As stated above, you do need to floor the pedal. And I mean completely. That's how you explain to it that you want maximum power. Let up a little bit, and it will think that you want to let up the power. Makes sense, right? :) |
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| GMTURBO43 |
| The engineering degree in me says there is some headroom left above redline - so redline is safe :) Need to make sure it's "In Spec" ;) |
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| Kan-O-Z |
I would guess the reason that the Murano doesn't actually go to redline or beyond is that it is not needed!
Let's think about this for a second. If you want the ultimate acceleration then the best way to get it is to get the RPMs to right where the engine is producing the highest horsepower. In most cars, redline actually produces less than the maximum hp!
So why redline any car? Well the answer to this is that acceleration is directly related to the average hp. So even though redline produces less than max hp, as soon as the next consecutive gear is achieved the rpm drops putting it close to the max hp rpm range. So in essence, redlining a car is only beneficial because the average rpm is close to the max hp rpm.
In a CVT, this method need not apply as this transmission is advanced enough that instead of hovering around the max hp rpm(by passing it redlining then going below it as soon as you shift gear), why not just stay put at max hp rpm. For the Murano this is 5600 rpm. There is really no need to redline as this would actually be lower performance than at 5600 rpm. |
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| Kan-O-Z |
| Sorry, instead of 5600 rpm, I meant 5800 rpm as the max hp rpm for the Murano. |
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| jaak |
| Drive around in L for a few minutes... You'll find a very different personality. Higher engine braking and the engine rpm will stay up there a fair bit. |
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| Tyler_Canada |
quote:
Originally posted by Kan-O-Z
I would guess the reason that the Murano doesn't actually go to redline or beyond is that it is not needed!
Let's think about this for a second. If you want the ultimate acceleration then the best way to get it is to get the RPMs to right where the engine is producing the highest horsepower. In most cars, redline actually produces less than the maximum hp!
So why redline any car? Well the answer to this is that acceleration is directly related to the average hp. So even though redline produces less than max hp, as soon as the next consecutive gear is achieved the rpm drops putting it close to the max hp rpm range. So in essence, redlining a car is only beneficial because the average rpm is close to the max hp rpm.
In a CVT, this method need not apply as this transmission is advanced enough that instead of hovering around the max hp rpm(by passing it redlining then going below it as soon as you shift gear), why not just stay put at max hp rpm. For the Murano this is 5600 rpm. There is really no need to redline as this would actually be lower performance than at 5600 rpm.
This is all true, except you mean torque instead of horsepower. Torque is instant power at a given RPM, horsepower is the Torque times distance travelled. Torque is what you feel as "power".
With this engine, there should be 2 torque peaks, one in the lower RPM range (below 4000) and one in the upper. At 4000 RPM, the intake area is opened more.
I have the pop charger, so these RPMs are a bit higher than those with a stock intake. I've found the lower torque peak to be about 3250, and the upper one to be about 5100 RPM.
So if you can manipulate the throttle to keep the RPMs at those values, you'll get better acceleration.
BTW, the TechnoSquare ECU that I'm looking at getting ups the redline to 7100, which is a common number that ECU upgrades use for this engine. |
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| Tyler_Canada |
| Oh, and it's MUCH easier to redline when flooring it from a stop than doing it while moving at any speed. |
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| Julio Bro! |
About floring the pedal, I'm not looking for the redline, I'm testing how it accelerates and I'm feeling something odd. And I say "feeling" because this might be just my perception.
From a standstill, when floored, rpms go to like 5k or 6k and the vehicle comes to 50 mph very, very fast...like a rocket. But after that it doesn't seem to accelerate much more, but rpms are high...like reaching a flat point. Seems like straining the engine.
Now, doing the same test, after reaching I get the pedal a bit back and I hear and feel the vehicle "shifting" and giving more speed.
Have you experienced this? Is this the normal behaviour for the Murano's CVT system? |
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| Tyler_Canada |
| I assume this is normal, mine has worked that way from the beginning. Some people might not notice it if they let off on the gas too quickly. I try to get other people to experience this when they are driving my MO, but they never let off on the gas slowly enough. |
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| Julio Bro! |
It seems to me that the computer is programed to move rpms linearly with the gas pedal. The CVT will try to maintain the revolutions as high as possible when floored and positions in between depending on how deep the pedal is pressed.
If this is the actual working, then there's a catch, because the power band of all engines depend on rpms and that's why conventionally you have shifting gears.
So, if the engine just stays at the top rpms then acceleration will be limited if the CVT doesn't move between peak torque and peak hp. This is done beautifully at moderate/low driving, you can see the rpms changing for a given pedal position.
If the system is bias towards speed, as in the pedal position dictates speed, then the case is worst when floored. The CVT should get peak torque up to a given speed, then move to peak hp for top acceleration on to the top speed dictated by the pedal.
If bias towards rpms, then at the last stage top acceleration would go on to the top speed available for the given rpms.
It could be a combination of both, but I think it works bias at speed. The other modes offered with D go for more torque at the wheels.
Probably the program will be improved with customer reports, but I definitely feel the lag after 50mph when floored. I don't remember the peak rpms, but I think it goes over them, and we all know that there's not much power near the top. |
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| Eric L. |
Yeah theoretically the CVT should not ever exceed the hp peak, where the engine is providing maximum acceleration. But it does anyways, so there must be a good reason the engineers programmed the CVT computer to let it do so.
In a conventional manual or automatic, it makes sense to exceed the hp peak RPM since this may push the revs into a meatier part of the powerband after the next upshift. For the CVT, this is not the case. |
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| HuskyFan |
quote:
Originally posted by Eric L.
Yeah theoretically the CVT should not ever exceed the hp peak, where the engine is providing maximum acceleration. But it does anyways, so there must be a good reason the engineers programmed the CVT computer to let it do so.
In a conventional manual or automatic, it makes sense to exceed the hp peak RPM since this may push the revs into a meatier part of the powerband after the next upshift. For the CVT, this is not the case.
If the engine never exceeded the rpm's @ peak hp you limit the top speed available. The SE 6 speed manual mode for example would not be able to go to the redline for those who care about such things. |
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| njjoe |
quote:
Originally posted by Eric L.
Yeah theoretically the CVT should not ever exceed the hp peak, where the engine is providing maximum acceleration. But it does anyways, so there must be a good reason the engineers programmed the CVT computer to let it do so.
In a conventional manual or automatic, it makes sense to exceed the hp peak RPM since this may push the revs into a meatier part of the powerband after the next upshift. For the CVT, this is not the case.
How's this for a reason? - limiting strain on the CVT |
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| Eric L. |
quote:
Originally posted by HuskyFan
If the engine never exceeded the rpm's @ peak hp you limit the top speed available. The SE 6 speed manual mode for example would not be able to go to the redline for those who care about such things.
Well for acceleration purposes, the CVT should theoretically limit it to peak hp RPM (5800). Only when the gear you are in no longer permits the engine to rev up to the peak hp rpm should a lower gear (and higher RPM) should accessed. This would then apply for top speed runs.
The MO is electronically speed limited by the ECU anyways (due to the T-rated tires), so redline and top speed do not necessarily apply in our case as it would for a drag limited vehicle. |
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| Julio Bro! |
At the very least, this is an odd behaviour and, apparently, in order to get the best acceleration we must learn to regulate the gas pedal accordingly.
Maybe later, when they have a better management software, we could get an "upgrade"...for a low fee.:cool: |
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| hfelknor |
"... "upgrade"...for a low fee."
Low Fee Nissan?
First Nissan?
Homer :D |
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| Julio Bro! |
quote:
Originally posted by hfelknor
"... "upgrade"...for a low fee."
Low Fee Nissan?
First Nissan?
Homer :D
Yeah I know. But, it'll be just software. |
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| Tyler_Canada |
| I've mentioned this numerous times in other threads, but I'll say it again. If you can use the throttle and keep the RPMs on the torque peak, you will get better acceleration than just flooring it. Try to keep the RPMs at 5000 and you'll see what I'm talking about. |
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| zebelkhan |
quote:
Originally posted by Tyler_Canada
I've mentioned this numerous times..., but I'll say it again....
You sound just like me talking to my kid....:2: |
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| EasternPA |
quote:
Originally posted by Julio Bro!
Now, doing the same test, after reaching I get the pedal a bit back and I hear and feel the vehicle "shifting" and giving more speed.
Have you experienced this? Is this the normal behaviour for the Murano's CVT system?
I never hear any changes coming from the CVT itself, but I do feel a plateau of sorts while it gets itself reorganized for the 60-100mph segment. I always enjoy shifting an automatic up and down with the throttle, so it took some getting used to with the CVT. There are ways to control its personality without switching to Ds, but those ways are just harder to find. With all the rentals I drive, I have "autoshifting" in a Taurus down to a science. The "floor it and flutter to 3/4" move to downshift a Taurus has no use in the Murano, that's for sure.
I find in the Murano I get the best power curve (from stopped) out of nearly flooring it and then slowly fading to 3/4 pedal between 50 and 60. Come back into it a little, and you'll sail right through the 60's and 70's, it'll get serious in the 80's and glide thru the 90's to a comfortable 100. Stay consistent with the throttle and you'll see the tach fade. Keep going in and out and the rpms will be all over the place -- 2.5 to 5. I know you're asking who goes from stopped to 100, but every Sunday night my wife and I have dinner at my in-laws, and they live right near a highway on ramp. When its time to go, its time to go! |
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| njjoe |
EasternPA-
"When its time to go, its time to go!" I absolutely love your excuse for going from 0 to 100. That is great!!! It gives you something to look forward to on Sunday nights!
-njjoe |
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| jaak |
quote:
Originally posted by Julio Bro!
Yeah I know. But, it'll be just software.
Funny how the perception of software is that it's cheap... It's only cheap when you're selling millions and millions of copies on low cost media, distributing the engineering costs over a large customer base.
There's a limited number of Muranos, which to upgrade, cost facilities and special tools to install the firmware.
The only way I've seen free upgrades is through warranty claims, if you can find something wrong with the older version.
Otherwise, they'd rather sell you a new one.
I wonder if it's any easier to control with the manual shift? |
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| Eric L. |
High-larious!!! :D
quote:
Originally posted by EasternPA
I never hear any changes coming from the CVT itself, but I do feel a plateau of sorts while it gets itself reorganized for the 60-100mph segment. I always enjoy shifting an automatic up and down with the throttle, so it took some getting used to with the CVT. There are ways to control its personality without switching to Ds, but those ways are just harder to find. With all the rentals I drive, I have "autoshifting" in a Taurus down to a science. The "floor it and flutter to 3/4" move to downshift a Taurus has no use in the Murano, that's for sure.
I find in the Murano I get the best power curve (from stopped) out of nearly flooring it and then slowly fading to 3/4 pedal between 50 and 60. Come back into it a little, and you'll sail right through the 60's and 70's, it'll get serious in the 80's and glide thru the 90's to a comfortable 100. Stay consistent with the throttle and you'll see the tach fade. Keep going in and out and the rpms will be all over the place -- 2.5 to 5. I know you're asking who goes from stopped to 100, but every Sunday night my wife and I have dinner at my in-laws, and they live right near a highway on ramp. When its time to go, its time to go!
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| b0xdesigns |
| I redline my mo! |
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| Julio Bro! |
quote:
Originally posted by EasternPA
...nearly flooring it and then slowly fading to 3/4 pedal between 50 and 60. Come back into it a little, and you'll sail right through the 60's and 70's, it'll get serious in the 80's and glide thru the 90's to a comfortable 100. Stay consistent with the throttle and you'll see the tach fade...
See? That's what I'm talking about. You can't just floor it and expect the CVT to do great...there must be some pedal regulation in order to get the best acceleration.
Hey EasternPA, don't you find that a little odd, being the CVT such a sophisticated system? Did you expect it to go smoothly the first time? |
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