Is Mazda's SkyActiv the best GDI system?

[Mykl]

Originally Posted By: L_Sludger
I think of 'skyactiv' tech to be only a mere notch above Nissan's "PureDrive" system. Simple mastrubation by sub-par manufacturers trying to pretend to be relevant while they're hopelessly outclassed and rendered utterly irrelevant by the facts of their competition and the market.


Uh, what?

 

[jrustles]

Originally Posted By: Mykl
Originally Posted By: L_Sludger
I think of 'skyactiv' tech to be only a mere notch above Nissan's "PureDrive" system. Simple mastrubation by sub-par manufacturers trying to pretend to be relevant while they're hopelessly outclassed and rendered utterly irrelevant by the facts of their competition and the market.


Uh, what?

 

[jrustles]

Originally Posted By: Ben99GT
Originally Posted By: jrustles
Ti-VCT...something inane about Titanium...It's two hydraulic cam phasers.


False. Ford is using cam torque actuated phasers.


False?
Curious how you'd consider backlash-assisted, hydraulic actuation such as Borg-Warner's CTA, as not hydraulic cam phasing? The spring backlash doesn't degree and lock the cam, oil does.

 

[Ben99GT]

Originally Posted By: jrustles
Originally Posted By: Ben99GT
Originally Posted By: jrustles
Ti-VCT...something inane about Titanium...It's two hydraulic cam phasers.


False. Ford is using cam torque actuated phasers.


False?
Curious how you'd consider backlash-assisted, hydraulic actuation such as Borg-Warner's CTA, as not hydraulic cam phasing? The spring backlash doesn't degree and lock the cam, oil does.


Rotational cam torque is what is used to move the oil, and thus camshaft centerlines, as opposed the strictly hydraulic cam phasers which depend on oil pressure entirely for phasing.

 

[jrustles]

Originally Posted By: Ben99GT


Rotational cam torque is what is used to move the oil,
and thus camshaft centerlines, as opposed the strictly hydraulic cam phasers which depend on oil pressure entirely for phasing.


I use the word "backlash" to describe "the reversing torque caused by the slope of the cams". It's important to describe that because it shouldn't be suggested as 'drag' or the force required to move turn the cam (which includes frictional losses) that this principle is based on, else one could not advance the timing. The backlash provides both forward and reverse torque, thus the ability to retard and advance timing. The side of the phaser in which the oil is put allows the backlash effect to degree the phaser as oil is metered (at gallery pressure FYI) by the hydraulic solenoid in the head.

Borg-Warner's solution to harness the backlash for actuation assistance purposes is really all this is. The oil being fed into the chambers is still fed at gallery pressure, so even to say that there is NO work done by hydraulic pressure here is not correct. This is precisely why I called it what it is; backlash-assisted hydraulic cam phasing.

I guess my point before establishing it as a hydraulic unit, is that it retains the pitfalls of a hydraulic device, such as susceptibility to viscosity (temp, grade)) -harnesing backlash energy to the mix simply improves performance, but it's performance will still vary with viscosity. I don't see precision or latency matching that of an electronic servo unit

 

[Ben99GT]

Originally Posted By: jrustles
This is precisely why I called it what it is; backlash-assisted hydraulic cam phasing.


Had you made that distinction originally, I wouldn't have made the reply I did. I took your original statement to imply Ford was using the older OPA style phasers, as they did on the 4.6/5.4 3Vs from MYs 2004-2010.

Quote:
I guess my point before establishing it as a hydraulic unit, is that it retains the pitfalls of a hydraulic device, such as susceptibility to viscosity (temp, grade)) -harnesing backlash energy to the mix simply improves performance, but it's performance will still vary with viscosity.


Not nearly to the degree the older OPA phasers would, CTA phasers allowed for significantly lower volume oil pumps because their operation is not as oil volume/pressure dependant.

 

[Bladecutter]

Originally Posted By: L_Sludger
I think of 'skyactiv' tech to be only a mere notch above Nissan's "PureDrive" system. Simple mastrubation by sub-par manufacturers trying to pretend to be relevant while they're hopelessly outclassed and rendered utterly irrelevant by the facts of their competition and the market.


Funny though that the Nissan and Mazda technology that you think is inferior to these un-named companies that you feel are superior to them, yet Mazda and Nissan's cars tend to have the top spots for fuel economy in their classes for purely ICE driven cars.

Nissan has been increasing fuel economy by refining their CVT transmissions.
Mazda added direct injection and newer highly refined transmissions to the Mazda 6 and Mazda 3, not to mention still made their cars enjoyable to drive, via tight chassis' that weigh less than the competition.

So what if they aren't resorting to turbochargers or even more use of hybrid technology in order to increase their fuel economy numbers? And their owners are reporting that the cars are hitting the EPA numbers, or beating them, in comparison to other manufacturers that claim EPA numbers (Ford, Hyundai), and get caught with their pants down, repeatedly.

So, which companies are inferior again?

BC.