These exhaust flame particles works even when ray tracing translucency is enabled!
5 different shapes/colors (with 4 smaller variations each) are included
Various spawn schemes such as One-Shot, Slow-Motion, Burst/Anti-Lag are included
It is part of the Automotive Extras pack, designed to be complimentary to the great Automotive Materials.
Available Here;
https://www.unrealengine.com/marketplace/en-US/product/fc78e1c4bd1c49678595c065450da38a
The pack also contains many more materials, such as sun-dependent metallic paint, titanium exhaust and more!