SkyActiv-Mazda's next generation of powertrains.
09-03-2011, 11:51 PM
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SkyActiv-Mazda's next generation of powertrains.
Mazda's new family of gasoline engines features the highest compression of 14:1 in a production car. mazda's answer to hybrids? what say u?
http://www.mazda.com/mazdaspirit/sky...ine/index.html
http://www.mazda.com/mazdaspirit/sky...ine/index.html
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09-06-2011, 11:55 AM
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If this ends up in the next miata in its current form I foresee aftermarket tuning end with the NC.
14:1 comp and sc\turbo sounds like a pretty good solution for detonation. Even a standalone ecu seems improbable...
Not to mention the lightened pistons\rods\crank...
Let`s hope the demise of the rotary forces Mazda to build a new "sports" engine and a chassi to go along that might continue the legacy where the rx-7 left off.
14:1 comp and sc\turbo sounds like a pretty good solution for detonation. Even a standalone ecu seems improbable...
Not to mention the lightened pistons\rods\crank...
Let`s hope the demise of the rotary forces Mazda to build a new "sports" engine and a chassi to go along that might continue the legacy where the rx-7 left off.
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09-06-2011, 12:05 PM
#8
??? Not sure what you mean by this Fae.
I applaud Mazda for their ongoing focus on KISS. Instead of trekking down the hybrid path and making cars that are complex, heavy and, down the road, maintenance and disposal nightmares . . . let's take what works and improve it.
The piston dome design seems counter-intuitive to me. I can see that it would contain part-throttle ignition in a localized area, but it looks like a flow nightmare, especially during the cam-lobe overlap region at TDC of the exhaust stroke. I suspect these engines are being designed with very little overlap.
I'm surprised to see that they are not using direct injection. That seems like an excellent way to control knock.
It is cool that they are coming up with a relatively common design for their gas and diesel engines. Accountants must be happy with that.
Looking forward to the ND's. Of course, all of this new technology and 14:1 CR's means that it will be that much harder to mod and tune. You could really blow stuff up quickly.
I applaud Mazda for their ongoing focus on KISS. Instead of trekking down the hybrid path and making cars that are complex, heavy and, down the road, maintenance and disposal nightmares . . . let's take what works and improve it.
The piston dome design seems counter-intuitive to me. I can see that it would contain part-throttle ignition in a localized area, but it looks like a flow nightmare, especially during the cam-lobe overlap region at TDC of the exhaust stroke. I suspect these engines are being designed with very little overlap.
I'm surprised to see that they are not using direct injection. That seems like an excellent way to control knock.
It is cool that they are coming up with a relatively common design for their gas and diesel engines. Accountants must be happy with that.
Looking forward to the ND's. Of course, all of this new technology and 14:1 CR's means that it will be that much harder to mod and tune. You could really blow stuff up quickly.
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09-06-2011, 12:17 PM
#9
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??? Not sure what you mean by this Fae.
I applaud Mazda for their ongoing focus on KISS. Instead of trekking down the hybrid path and making cars that are complex, heavy and, down the road, maintenance and disposal nightmares . . . let's take what works and improve it.
The piston dome design seems counter-intuitive to me. I can see that it would contain part-throttle ignition in a localized area, but it looks like a flow nightmare, especially during the cam-lobe overlap region at TDC of the exhaust stroke. I suspect these engines are being designed with very little overlap.
I'm surprised to see that they are not using direct injection. That seems like an excellent way to control knock.
It is cool that they are coming up with a relatively common design for their gas and diesel engines. Accountants must be happy with that.
Looking forward to the ND's. Of course, all of this new technology and 14:1 CR's means that it will be that much harder to mod and tune. You could really blow stuff up quickly.
I applaud Mazda for their ongoing focus on KISS. Instead of trekking down the hybrid path and making cars that are complex, heavy and, down the road, maintenance and disposal nightmares . . . let's take what works and improve it.
The piston dome design seems counter-intuitive to me. I can see that it would contain part-throttle ignition in a localized area, but it looks like a flow nightmare, especially during the cam-lobe overlap region at TDC of the exhaust stroke. I suspect these engines are being designed with very little overlap.
I'm surprised to see that they are not using direct injection. That seems like an excellent way to control knock.
It is cool that they are coming up with a relatively common design for their gas and diesel engines. Accountants must be happy with that.
Looking forward to the ND's. Of course, all of this new technology and 14:1 CR's means that it will be that much harder to mod and tune. You could really blow stuff up quickly.
http://www.motoiq.com/magazine_artic...echnology.aspx
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09-06-2011, 12:46 PM
#10
Stop posting until you read this:
http://www.motoiq.com/magazine_artic...echnology.aspx
http://www.motoiq.com/magazine_artic...echnology.aspx
I like how they use VVT to keep the intake valve open during part of the compression stroke at lower RPM's. That effectively makes this a variable compression ratio engine.
Don't see this one being MS'd.
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09-07-2011, 08:13 AM
#11
Originally Posted by MotoIQ article
To further reduce pumping losses, the Skyactiv engine has an unusual part-throttle cam control strategy. A lot of part throttle pumping loss is due to the engine fighting against a vacuum in the intake manifold caused by the partially closed throttle. At part throttle, the Skyactiv engine goes to a late closing intake valve mode so that the intake is still open on a large part of the compression stroke. As the piston travels upward, just enough air is forced out of the open intake valve to eliminate the vacuum in the intake manifold. Thus, at part throttle the cam timing controls engine output, not the throttle plate. The engine's super high compression ratio ensures stable combustion even when some of the cylinder pressure is leaked out during part throttle operation. This also helps reduce the chances of detonation if the engine is lugged in this mode. This strategy helps reduce overall pumping losses by 20 percent in the Skyactiv engine.
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