6G Celicas Forums

Hi

Ive read a bit about spark plugs and was thinking of getting the platinum NGK ones (BKR6EP-8/2215) as they have good reviews and are long life.
I was just wondering if i should go one colder and get the BKR7EP ones? I have a 3" exhaust and am running at 15psi. I don't often boost it so mostly stay under 12psi, but with the increase in boost would it be safer to have colder spark plugs for when i do thrash it or is it not a good idea or not necessary??

Thanks for the help in advance

This post has been edited by mikee: Aug 26, 2009 - 5:08 AM

i would go with the BKR7ES or part # 6067 (i think) i use them in all my boosted cars with no problems

going colder has to do with making more power.....1 step colder for every ~50-80hp or so

This post has been edited by playr158: Aug 26, 2009 - 11:16 AM

That sounds funky, I was always under the impression that you'd want a hotter spark to burn more fuel at once, creating a bigger explosion, creating more power.

I went with NGK Laser Iridiums. I installed them last night, the took the car out on a "spirited" drive through the mountains, have to say that they performed well. All in all I'd say that they're burning better than the standard Iridiums that I put in before.

-TC

Wrong. Its NOT the spark 'temperature' they're talking about here. Its the "tip" of the spark plug.
The insulator, electrode, and ground heat up when you run an engine, and stay about the same temperature the whole time, whether its in the compression, power, or intake stroke its about the same temp. Now why you would want a hotter tip DOES have to do with the efficiency of the burn, but more importantly, and why you'd want a colder tip, has to do with knock resistance. As many people know knock kills engines, and what many people may NOT know, is that knock may be caused by "hot spots" in your combustion chamber. When you compress air, or any matter, it gets hotter. Now, the more you compress it, the hotter it gets, and the more sensitive it gets to these "hot spots" in your engine. In a low compression engine, you need these hot spots for the fuel to vaporize and burn properly and completely. In a higher compression engine you don't need or want these hot spots because the compression heats the air/fuel enough to take care of this, and any more added heat may cause the fuel to detonate prematurely. Now as you can see, the plug temperature is a trade off between efficiency and safety. The higher the compression, static or dynamic (FI), the lower you want the temperature to be.

Ah,
So in theory you'll only need to worry about the "coldness" of your plug until you're running a high-compression top end.

Good thing I'm stock 5sfe, but I'll keep this in mind for when/if I ever do any compression work.

-TC

look at your old spark plugs. if they look clean you can afford to go colder.





Hot spark plugs are important to keep the tips clean as they burn off anything that sticks to the tip. If you constantly foul spark plugs, then you might want to change to a hotter spark plug. But if you take your spark plugs out and they look clean and your not getting any knock/pinging then stay with what you have.

Everything is burning perfectly, the only plugs I've ever fouled were in pocket bikes and go-peds due to carb tuning. :-D

-TC

This post has been edited by razor7: Aug 26, 2009 - 4:23 PM

ah yes. i also forgot that tidbit of information

oh man

do yourselves a favor and read this CORRECT information on sparkplugs

http://www.ngksparkplugs.com/techinfo/spar...&country=US