I hope this is not shared
http://www.foxnews.com/auto/2017/01/16/ ... 8.amp.html
So how did Mazda do it? We are going to take a few guesses, but as with most technologies, it didn’t happen overnight. In fact, we would say Mazda’s first big step was a few decades ago. The final piece of the puzzle is a technology Mazda has called Spark Controlled Compression Ignition (SPCCI), and we will exclusively get into how that ties into making HCCI work.
https://www.carsguide.com.au/car-news/m ... tion-36576The most recent Renesis-generation rotary that powered the RX-8 until 2012 was turbo-free aside from the limited-production hydrogen models sold in Japan and Norway. However 13B and 20B engines that preceded it in the FD RX-7 and JC Cosmo both used twin-sequential turbos to overcome the engine's intrinsic torque deficit at low revs.
The SkyActiv-R's biggest gain will likely revolve around the way it burns fuel, with Mazda developing unique methods for analysing and measuring the combustion process. Fujiwara explained that regular piston engines can be analysed with standard techniques, but the lack of such tools for rotary engines has hampered their efficiency in the past.
Previous rotary engines have also been compromised by the need to locate the spark plug outside the combustion chamber to allow the rotor to sweep past, but Fujiwara confirms this has been solved for the SkyActiv-R.
Considering the high compression ratio used by rotaries in general, this seems a natural fit with the homogeneous charge compression ignition (HCCI) expected for the second-generation SkyActiv 2 technology due in 2020. Like diesel engines, HCCI relies on extra-high compression to ignite fuel,eliminating the need for spark plugs altogether and reducing consumption and emissions significantly.
Fujiwara declined to officially confirm the move to compression ignition, but his wry smile response hinted this suggestion isn't far off the mark.
Given the likelihood the production RX-Vision will arrive as part of Mazda's 100th birthday celebrations in 2020, the incorporation of such landmark technology would make a lot of sense.
Just ran across this article myself. The author speculates that VVT & EGR are used as a coarse control, with spark and fuel injection used for fine control.bill shoe wrote: ↑28 Aug 2017, 22:15Pretty good tech article about this engine-
http://www.motoiq.com/MagazineArticles/ ... ngine.aspx
So how did Mazda do it? We are going to take a few guesses, but as with most technologies, it didn’t happen overnight. In fact, we would say Mazda’s first big step was a few decades ago. The final piece of the puzzle is a technology Mazda has called Spark Controlled Compression Ignition (SPCCI), and we will exclusively get into how that ties into making HCCI work.
A controlled flame front acting as a sort of second piston face. Except that one 'piston' has a variable shape and approach. The remaining fuel-air charge that gets sandwiched between these two faces enters HCCI.SPCCI is genius because it uses the same physics which causes knock, to well, cause knock. Remember, Skyactiv-G uses direct injection and Skyactiv-D uses fuel injectors which can spray many times in one combustion cycle. So, what we think SPCCI does is spray a tiny bit of fuel right at the spark plug and the fuel is ignited- creating a little frame front. That flame front then increases the pressure and temperature in the homogenous mixture; basically, the mixture is getting compressed from below by the piston and then above by this tiny flame front. The tiny flame front increases the pressure until the whole enchilada goes off. As fuel and spark can be controlled very precisely and very quickly, it gives the superfast fine-tuning adjustability knob to control the timing of the full HCCI combustion in the cylinder.
Recently Christian Horner said in an interview on motorsport.com
They have to use spark for ignition, it's in the rules, so it can't be HCCI. I guess you could say TJI is a hybrid of SI and HCCI?Brake Horse Power wrote: ↑07 Nov 2017, 00:13Recently Christian Horner said in an interview on motorsport.com
"They’ve taken away the sound; the passion and they’ve added too much complexity. They’ve become far removed from road car technology; they’re effectively turning into diesel engines in some cases."
Wouldn't he be referring to HCCI here?
He might be, but mainly I think he is referring to the fact that his engine supplier has troubles getting it right. Therefore the only logical conclusion is that it is too complexBrake Horse Power wrote: ↑07 Nov 2017, 00:13Recently Christian Horner said in an interview on motorsport.com
"They’ve taken away the sound; the passion and they’ve added too much complexity. They’ve become far removed from road car technology; they’re effectively turning into diesel engines in some cases."
Wouldn't he be referring to HCCI here?
RCIBrake Horse Power wrote: ↑07 Nov 2017, 00:13Recently Christian Horner said in an interview on motorsport.com
"They’ve taken away the sound; the passion and they’ve added too much complexity. They’ve become far removed from road car technology; they’re effectively turning into diesel engines in some cases."
Wouldn't he be referring to HCCI here?
He was probably having a pop at Merc & Ferrari for oil burning.Brake Horse Power wrote: ↑07 Nov 2017, 00:13Recently Christian Horner said in an interview on motorsport.com
"They’ve taken away the sound; the passion and they’ve added too much complexity. They’ve become far removed from road car technology; they’re effectively turning into diesel engines in some cases."
Wouldn't he be referring to HCCI here?