View Single Post
Old 11-14-2020, 07:30 PM   #2 (permalink)
serialk11r
Master EcoModder
 
Join Date: Jan 2012
Location: United States
Posts: 1,756

spyder2 - '00 Toyota MR2 Spyder
Thanks: 104
Thanked 407 Times in 312 Posts
Yup, Maserati MC20 and AMG One will use it.

The way it would be used on passenger cars is to use vast quantities of EGR dilution with stoichiometric AFR to improve low load efficiency and keep emissions down. The slightly increased combustion speed at high load is a plus, but it only buys a small boost in compression ratio and efficiency.

In Mazda's SPCCI, they're able to run something like 50% EGR dilution. I would expect around the same here. The issue with SPCCI is that the compression ratio is extra high to produce autoignition, which reduces mechanical efficiency and specific torque. Jet ignition allows a low-tumble, high flow port, and a more optimal compression ratio of ~14.

For even fairly large engines, you could cruise on the freeway with close to no manifold vacuum and very little heat escaping to the coolant due to low combustion temperature, for something like 40+% thermal efficiency at 50% load.

I'm not as optimistic about this technology because you do need a high-temperature resistant prechamber, and a method to get a more ignitable mixture in the prechamber. A sort of in between method that seems promising is "low temperature plasma" or corona discharge ignition: https://www.motortrend.com/news/july...asma-ignition/

Kind of like a bigger spark that can efficiently ignite more of the mix when it fires. They claim 25:1 AFR capability (so not as good as SPCCI or jet ignition) but that's still pretty solid. If it acts like a mega-spark-plug that burns significantly faster, then that would be most of the benefit of a fancier system for little cost.

Last edited by serialk11r; 11-14-2020 at 07:51 PM..
  Reply With Quote
The Following User Says Thank You to serialk11r For This Useful Post:
freebeard (11-14-2020)