My apologies if this has been posted before.âž¡ï¸ Hyundai "CVVD" continuous variable valve duration.
New Tech - CVVD
- Thread starter Mad_Hatter
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Thanks!
I haven't seen it here at BITOG although I have seen EE/Jason's review.
I haven't seen it here at BITOG although I have seen EE/Jason's review.
Originally Posted by Char Baby
Thanks!
I haven't seen it here at BITOG although I have seen EE/Jason's review.
ðŸ‘..ur welcome. I thought this was neat stuff. We sure have come a long way from pushrods, no?
Thanks!
I haven't seen it here at BITOG although I have seen EE/Jason's review.
ðŸ‘..ur welcome. I thought this was neat stuff. We sure have come a long way from pushrods, no?
4WD
$50 site donor 2024
At least pushrod mills have very short reliable chains … probably not the finest iteration of VVT … but still doable
Taking my chances with AFM for now …
Taking my chances with AFM for now …
already being discussed...
https://www.bobistheoilguy.com/foru...ble-duration-camshaft-system#Post5367829
https://www.bobistheoilguy.com/foru...ble-duration-camshaft-system#Post5367829
I didn't look at the Video but isnt the Fiat Multiair engine genius?
- or just overengineering and fragile?
- or just overengineering and fragile?
Originally Posted by Mad_Hatter
My apologies if this has been posted before.âž¡ï¸ Hyundai "CVVD" continuous variable valve duration.
[video:youtube]https://youtu.be/uhsgdwUX1w[video]
Whatever. My 370Z had that almost a decade ago (mine was a 2012, but Nissan did this in 2008 as a 2009YM car when the Z dropped).
and here is the result of that technology.
![[Linked Image from the370z.com]](http://www.the370z.com/members/semtex-albums-stillen-g3-intake-installation-picture1770-dyno-run-dynojet-after-installing-g3-intakes-i-did-so-we-could-compare-numbers-dyno-dynamics-306-4-dd-321-3-dj.jpg "[Linked Image from the370z.com]")
(this is after Stillen G3 intakes were installed. Those are worth about 20-25whp or so, and a decent bump on torque as well, but you can see the power curves)
I had some complaints about my 370Z, but the VQ37 was never one of them. Brilliant engine. Look at that torque curve...
It pulled just the same as my 2001 WS.6 LS1 6-speed car. Dig or roll. I even looked up Car and Driver's test data, and 0-60 and 5-60 are near identical, as are 1/4 mile ET and MPH, when compared to a C5 corvette (LS1, similar weight as the 370Z). Amazing what they did with that V6, although it didn't get as good a mileage on the highway as an LS1 C5, but, hey, lol!
My apologies if this has been posted before.âž¡ï¸ Hyundai "CVVD" continuous variable valve duration.
[video:youtube]https://youtu.be/uhsgdwUX1w[video]
Whatever. My 370Z had that almost a decade ago (mine was a 2012, but Nissan did this in 2008 as a 2009YM car when the Z dropped).
and here is the result of that technology.
(this is after Stillen G3 intakes were installed. Those are worth about 20-25whp or so, and a decent bump on torque as well, but you can see the power curves)
I had some complaints about my 370Z, but the VQ37 was never one of them. Brilliant engine. Look at that torque curve...
It pulled just the same as my 2001 WS.6 LS1 6-speed car. Dig or roll. I even looked up Car and Driver's test data, and 0-60 and 5-60 are near identical, as are 1/4 mile ET and MPH, when compared to a C5 corvette (LS1, similar weight as the 370Z). Amazing what they did with that V6, although it didn't get as good a mileage on the highway as an LS1 C5, but, hey, lol!
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Originally Posted by Ws6
Originally Posted by Mad_Hatter
My apologies if this has been posted before.âž¡ï¸ Hyundai "CVVD" continuous variable valve duration.
[video:youtube]https://youtu.be/uhsgdwUX1w[video]
Whatever. My 370Z had that almost a decade ago (mine was a 2012, but Nissan did this in 2008 as a 2009YM car when the Z dropped).
and here is the result of that technology.
(this is after Stillen G3 intakes were installed. Those are worth about 20-25whp or so, and a decent bump on torque as well, but you can see the power curves)
I had some complaints about my 370Z, but the VQ37 was never one of them. Brilliant engine. Look at that torque curve...
It pulled just the same as my 2001 WS.6 LS1 6-speed car. Dig or roll. I even looked up Car and Driver's test data, and 0-60 and 5-60 are near identical, as are 1/4 mile ET and MPH, when compared to a C5 corvette (LS1, similar weight as the 370Z). Amazing what they did with that V6, although it didn't get as good a mileage on the highway as an LS1 C5, but, hey, lol!
Were these mass production vehicles?
Originally Posted by Mad_Hatter
My apologies if this has been posted before.âž¡ï¸ Hyundai "CVVD" continuous variable valve duration.
[video:youtube]https://youtu.be/uhsgdwUX1w[video]
Whatever. My 370Z had that almost a decade ago (mine was a 2012, but Nissan did this in 2008 as a 2009YM car when the Z dropped).
and here is the result of that technology.
(this is after Stillen G3 intakes were installed. Those are worth about 20-25whp or so, and a decent bump on torque as well, but you can see the power curves)
I had some complaints about my 370Z, but the VQ37 was never one of them. Brilliant engine. Look at that torque curve...
It pulled just the same as my 2001 WS.6 LS1 6-speed car. Dig or roll. I even looked up Car and Driver's test data, and 0-60 and 5-60 are near identical, as are 1/4 mile ET and MPH, when compared to a C5 corvette (LS1, similar weight as the 370Z). Amazing what they did with that V6, although it didn't get as good a mileage on the highway as an LS1 C5, but, hey, lol!
Were these mass production vehicles?
This is also on the new GM 4 cyl that is in the Silverado and Sierra 1500 pickup.
Is it CVVL or CVVD?...because Hyundai is claiming this is the first true production CVVD engine. So are they lying? It's also being touted as a first of kind in industry mags like R &T, Car & Driver, MotorTrend etc...
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Originally Posted by Mad_Hatter
Is it CVVL or CVVD?...because Hyundai is claiming this is the first true production CVVD engine. So are they lying? It's also being touted as a first of kind in industry mags like R &T, Car & Driver, MotorTrend etc...
They may differ in some nuance from what Nissan did a decade ago, but functionally I kindof doubt it.
Is it CVVL or CVVD?...because Hyundai is claiming this is the first true production CVVD engine. So are they lying? It's also being touted as a first of kind in industry mags like R &T, Car & Driver, MotorTrend etc...
They may differ in some nuance from what Nissan did a decade ago, but functionally I kindof doubt it.
Originally Posted by Ws6
Originally Posted by Mad_Hatter
Is it CVVL or CVVD?...because Hyundai is claiming this is the first true production CVVD engine. So are they lying? It's also being touted as a first of kind in industry mags like R &T, Car & Driver, MotorTrend etc...
They may differ in some nuance from what Nissan did a decade ago, but functionally I kindof doubt it.
technically Fiat MultiAir does both...
Originally Posted by Mad_Hatter
Is it CVVL or CVVD?...because Hyundai is claiming this is the first true production CVVD engine. So are they lying? It's also being touted as a first of kind in industry mags like R &T, Car & Driver, MotorTrend etc...
They may differ in some nuance from what Nissan did a decade ago, but functionally I kindof doubt it.
technically Fiat MultiAir does both...
I couldn't find anything describing either the Nissan or Fiat "duration" as independent of the lift profile. In other words, the duration is fixed in both those VVA systems. Can you point me to something showing the duration can be altered independent of the lift profile?
By comparison, the Hyundai VVA can not only alter the lift profile but how long the valve stays open, both being independent of one another. That may be why/how Hyundai's calling this a "first".
By comparison, the Hyundai VVA can not only alter the lift profile but how long the valve stays open, both being independent of one another. That may be why/how Hyundai's calling this a "first".
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Originally Posted by Mad_Hatter
I couldn't find anything describing either the Nissan or Fiat "duration" as independent of the lift profile. In other words, the duration is fixed in both those VVA systems. Can you point me to something showing the duration can be altered independent of the lift profile?
By comparison, the Hyundai VVA can not only alter the lift profile but how long the valve stays open, both being independent of one another. That may be why/how Hyundai's calling this a "first".
The link is to a pdf download from Southern Illinois University Carbondale.
https://opensiuc.lib.siu.edu/cgi/viewcontent.cgi?article=1035&context=auto_pres
Here are the major modes of operation.
I couldn't find anything describing either the Nissan or Fiat "duration" as independent of the lift profile. In other words, the duration is fixed in both those VVA systems. Can you point me to something showing the duration can be altered independent of the lift profile?
By comparison, the Hyundai VVA can not only alter the lift profile but how long the valve stays open, both being independent of one another. That may be why/how Hyundai's calling this a "first".
The link is to a pdf download from Southern Illinois University Carbondale.
https://opensiuc.lib.siu.edu/cgi/viewcontent.cgi?article=1035&context=auto_pres
Here are the major modes of operation.
Basically you design your camshaft for the maximum lift and duration. With a combination of timing and PWM duty cycle you achieve nearly anything inside that maximum cam profile, all the way down to zero (no reaction).
But in the MA system the valve duration has only 2 profiles, long and short.. because the duration is coupled to the lift profile. When you change lift profile you do change the duration, to some degree. But unless the duration is decoupled from the valve lift profile you're stuck with just 2 phases of duration, fast and slow - there's no in between. But by decoupling the valve duration from the valve lift, Hyundai's system can achieve more variation in duration profiles
Maybe this is why FCA doesn't (even) describe MultiAir as CVVD but rather VVT+VVL. Because it doesn't achieve true various valve duration independent of valve lift?
Maybe this is why FCA doesn't (even) describe MultiAir as CVVD but rather VVT+VVL. Because it doesn't achieve true various valve duration independent of valve lift?
Originally Posted by Mad_Hatter
But in the MA system the valve duration has only 2 profiles, long and short.. because the duration is coupled to the lift profile. When you change lift profile you do change the duration, to some degree. But unless the duration is decoupled from the valve lift profile you're stuck with just 2 phases of duration, fast and slow - there's no in between. But by decoupling the valve duration from the valve lift, Hyundai's system can achieve more variation in duration profiles
Maybe this is why FCA doesn't (even) describe MultiAir as CVVD but rather VVT+VVL. Because it doesn't achieve true various valve duration independent of valve lift?
My understanding is by varying the PWM duty cycle they can move the valve independently of the valve profile. It is not shown in those slides, but it is referred to in the wording. With a partial duty cycle, you can partially pressurize the oil, allowing the valve to open more slowly then the profile is trying to drive it. I believe that starts getting into too much details of operation, and clearly not open for public discussion...which is why there are no graphs showing that mode of operation, just words.
Maybe I am just thinking ideally, but I am a hydraulics systems engineer...and in theory, what I describe would be 100% plausible.
But in the MA system the valve duration has only 2 profiles, long and short.. because the duration is coupled to the lift profile. When you change lift profile you do change the duration, to some degree. But unless the duration is decoupled from the valve lift profile you're stuck with just 2 phases of duration, fast and slow - there's no in between. But by decoupling the valve duration from the valve lift, Hyundai's system can achieve more variation in duration profiles
Maybe this is why FCA doesn't (even) describe MultiAir as CVVD but rather VVT+VVL. Because it doesn't achieve true various valve duration independent of valve lift?
My understanding is by varying the PWM duty cycle they can move the valve independently of the valve profile. It is not shown in those slides, but it is referred to in the wording. With a partial duty cycle, you can partially pressurize the oil, allowing the valve to open more slowly then the profile is trying to drive it. I believe that starts getting into too much details of operation, and clearly not open for public discussion...which is why there are no graphs showing that mode of operation, just words.
Maybe I am just thinking ideally, but I am a hydraulics systems engineer...and in theory, what I describe would be 100% plausible.
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