Also we’ve seen improvement using the “V’d” ground strap like Larry showed. Also remember the NGK number sequence. Higher number equals colder plug…reverse of all other brands.
Sorry for me keeping on adding comments to this thread’ but we dyno’d nothing but spark plugs one full day along with SkiDoo’s engineers. But watch out for the extended tips though. More power sure, but they can create a hot spot that could induce detonation. One reason most two cycle sleds come with “ECS” NGK plugs. Little less hp though
I like these NGK racing plugs R5672A-8, non-resistor, projected nose and clipped back ground strap. Pretty cold but with a good MSD ignition they work well.
Yes, it appears so. I used to use Champion RV17YC in my 72 Skylark 350. It liked those plugs. They have very projected nose, and I could feel the difference between the recommended R45TS, and them. https://www.amazon.com/Champion-RV17YC-2pk-Copper-Spark-Stock/dp/B00GG18Z3G
Yes a lot more projected i see. Also more than the Champion RV12YC. Do you know why these type of plugs did not come from the factory in the engine? As the projected plugs seem the best choice.
Okay, i tried NOS AC Delco R44TS once and it idled and ran not good at all. Put the NGK back in and all was good again.
I do know why the snowmobile industries went with the ECS style NGK plugs. Fact-to reduce warranty claims from burn downs. We had to richen up the fuel/air mixture by two sizes, when switching to the projected tip designed plug. EGT’s showed way higher dangerous numbers. Near or just under 1,400 degrees. The ECS’s are just the opposite of the r44t, / ts plugs. The tip hardly sticks out into the combustion chamber and the plug tip design is actually shrouded… numbers are BR8ECS, BRS9ECS I Believe
Yes, of course. More of an example of tip design differences and effects they have. But these are the actual plugs that the snowmobile industry uses. Sorry for the confusion…
I used some Torco for awhile, and they turned the plugs darker. I also threw in some leaded gasoline because I had had it about 2 years, and I didn't want it to go bad. All that made the plugs a lot darker than they normally would be. They were also in the car for over a year. I have a more representative picture, I just have to find it.
Larry- you probably know this. But when running higher octane fuel like race gas, they all burn cooler and thus makes it harder to ignite than commercial road fuel. So normally to get the correct burn and performance we need to jet down. Especially with street or in our case trail friendly lower compression. Especially with our stockers. We were sponsored by many of the race fuel companies over the years, received race gas by the 55 gallon barrels. Torco was with us to the end. Their fuel rocked! And always passed tech. And the engineers were always available to us.
While when we dyno’d different race fuels throughout two days, Torco was the winner. We had the luxury to pick which fuel brand would sponsor us. Jetting and timing (timing adjustment is a bitch on a two stroke) was adjusted for max results with each brand.
