Just curious if anybody is running BR9 plugs to the BR8 stock plugs and what your setup is. Did you have any improvement in performance over 8s?......foul out 8 or 9s making the switch?
Anybody running BR9 plugs?
- Thread starter 99LRDblaster
- Start date
IMO, I don't think a BR9 plug is going to make a difference on a properly-tuned stock or near-stock engine. This plug is one heat range cooler than the stock BR8 and will probably foul out sooner than the BR8 in real-world use, especially by people who don't have their engines dialed-in correctly or like to run them rich. Personally, I just run the factory BR8 plug and have had no problems.
That being said, you may see an advantage with running a cooler plug in a big-bore or heavily-modified engine, especially if the head has been re-designed and/or ignition timing advanced. A manufacturer selects and recommends a spark plug for their engine based on several factors; one of them being said engine's normal operating temperature.
A BR8 plug works well for a stock or near-stock engine, but some heavily-modified engines (esp big-bores and stock engines already bored .080 over) tend to run hotter than what the factory planned. These engines would probably benefit from the use of a cooler plug, to shed heat faster from the firing end of the plug and top of the combustion chamber. This would be a good question for an engine builder here; they could speak from more practical experience than I.
That being said, you may see an advantage with running a cooler plug in a big-bore or heavily-modified engine, especially if the head has been re-designed and/or ignition timing advanced. A manufacturer selects and recommends a spark plug for their engine based on several factors; one of them being said engine's normal operating temperature.
A BR8 plug works well for a stock or near-stock engine, but some heavily-modified engines (esp big-bores and stock engines already bored .080 over) tend to run hotter than what the factory planned. These engines would probably benefit from the use of a cooler plug, to shed heat faster from the firing end of the plug and top of the combustion chamber. This would be a good question for an engine builder here; they could speak from more practical experience than I.
I know a lot of people do it for higher compression and timing advances. That's why I was interested in hearing what setups people were running if they had BR9s.
only really need a BR9 with a head mod, ken told me to run one when i had him do my head, but i only rode it for about 5 minutes lol
but its for running with more compression is the way i took it
okay, im sure it would be fine just wanted to know and im bored as crap in school right now lol
Just as an update, I bumped up to a BR9 since I'm around 180ish psi compression. On that compression alone, my BR8s were running too hot. Switched to BR9s and the plugs look better and where they should be. I just advanced the timing as well, so I'll have to check them out again and see where they are are. I might even have to go up to BR10, but I doubt it.
I didn't see fifty degree difference, My situation was 30ish. Still, I do what the builder (Ken) recommends, which is a BR9-in my situation. That is what I run. Now if the weather would just make up it's mind, I could get this air striker jetted in...
God damn man........you have no idea how much I agree with that last statement. X(
Any of you guys messed with the stock plug designs?
Like if I take the BR9 and cut the ground strap back to expose more of the spark?....or grooving the center electrode?
Like if I take the BR9 and cut the ground strap back to expose more of the spark?....or grooving the center electrode?
A 10 in what?.......an actual Blaster engine or your 400?
B10ES non resistor w/high compression, +4 timing, re-chambered head, Nology ignition, on alky in a YZ400.
Timing, compression, head design, fuel, ambient temps, ignition all come into play with choosing a plug.
Just because you can run a 10 without fouling doesn't mean it's what is making the best power. Your low rpm power could be suffering.
The rule will always be run the hottest plug that you can.
In my case the 9 was pre-igniting.
