Spark plug Question
- Thread starter edi
- Start date
Do NOT use platinum in a boosted car... Copper or iridium... Iridium is my fav... I was running the NGK Iridiums, and I loved them... *BKR6EIX-11 3764* I had Bosch Platinums in there, and it was pinging like crazy, and the car really ran like shit... Swapped for the iridiums, and it never pinged, and ran like a dream...
i have been using Autolite 3923 coppers with great luck. copper is better at conducting spark than platinum or iridium, but doesn't last as long. i change my plugs when i change my oil, every 5k miles.
another nice thing about the 3923 coppers- they're available pretty much everywhere, and are cheap as hell!
-shaeff
another nice thing about the 3923 coppers- they're available pretty much everywhere, and are cheap as hell!
-shaeff
I concur Shaeff, excellent copper plug, and I had those in when I broke 500hp in the silver supra... I plan on usning them again during break in, but I still love the smoothness I got with those iridiums... But like I said, I made 500+ on coppers, no miss, no problems...
i have had luck with the autolites also, but there is a slight* miss at idle with them.(-----------------------miss------------------------------------miss). Not bad at all-but this time I am trying the NGK 3330's-no miss at idle with those. I would also recommend that whatever you get is copper as platnum does not do well in turbo cars. I dropped my 1/4 mile time by .4 seconds just switching from platnum to copper.
polobai said:
There's a reason for that
Depending on your wires, the Autolite 3923's are about 1/8" shorter than stock. It can make a poor connection with the wires, cause arcing, and hence a miss. If you want to use copper plugs, try the NGK BCPR6ES or one step cooler, the BCPR7ES
edi said:
Denso plugs are good...about the same quality as NGK.
hmmmm, sounds like I need to swap of the platinum champions I put in for some NGK iridiums or coppers. Maybe thats why I have a slight miss
QFT!!! Just say NO to platinum in boosted cars...jmanbball said:
Reign_Maker said:
polobai said:
ive been using the autolite 3923s as well asn expierence the miss like poloabi discribe. very random miss
Densos are japanese just like the NGK's. From what I hear, they are basically pretty much the same damn thing and doesn't matter which one of the 2 you buy. Here in PR no one sells the NGK coppers anymore.... someone brainwashed every single store into selling either platinums as "stock replacements", or go "racing racing" with the iridiums.
PS: The racing thing is a local joke.... everything here that isn't stock is called "racing" with a funny puerto rican accent. I even have to force myself to say it like that. Guess I should do a voice record on that hehe.
PS: The racing thing is a local joke.... everything here that isn't stock is called "racing" with a funny puerto rican accent. I even have to force myself to say it like that. Guess I should do a voice record on that hehe.
jpeek29208 said:
Every one I know including myself has this "miss" at idle.
I still swear by autolites.
Had the Autolites and experienced the same miss with MSD wires. Switched to NGK iridium's and it completely went away.
The Autolites are good plugs...they're just a bit too short. Take a look at this thread...last post:
http://www.mkiiitech.com/forums/viewtopic.php?t=893
The Autolites are good plugs...they're just a bit too short. Take a look at this thread...last post:
http://www.mkiiitech.com/forums/viewtopic.php?t=893
Denso are OEM plugs, so basicly they just cant have any problems with it I was running Denso Iridiums from Toyota Dealer since the beginning and ware great, now i've swithced to NGK Iridiums and my idle is perfect, I love when my cars idles so smooth
I was running Denso Iridiums from Toyota Dealer since the beginning and ware great, now i've swithced to NGK Iridiums and my idle is perfect, I love when my cars idles so smooth 
We had a really good discussion on this topic awhile ago, and came to some informative conclusions.
http://www.supramania.com/forums/showthread.php?t=11838
http://www.supramania.com/forums/showthread.php?t=11838
What is the code on all the Iridiums that everyone is using? The ones that NGK's website suggest for a MK3 turbo are BCPR6EIX. Or is everyone else using the BKR6EIX-11 3764 that are suggested by Reign Maker in post #2?
What is everyone paying for there set?
What is everyone paying for there set?
Fletch124 said:
edi said:
The -11 indicates "Wide Gap", in this case .044"
If you are running anything over stock boost, you are going to want to gap your plugs down anyway, so selecting the ones without a dash number on the end are better for those applications.
Here, this should help:
And since we are on the topic, here's my $.02 on it.
Don't forget that one of the primary purposes of a spark plug is to remove heat from the firing chamber. A cooler plug is a good choice if your current plugs plugs are blistering, or if you suspect pre-ignition/detonation, due to increased boost, increased compression, or you have leaned-out the A/F mixture. All of the above increase cylinder temps and you should compensate at the spark plug level.
Ideally, the goal is a cylinder temperature to be between 900 degrees fahrenheit (500 C) and 1500 degrees fahrenheit (850 C). Colder than 900 degrees fahrenheit (500 C) will lead to carbon build-up and fouling which leads to mis-fire; hotter than 1500 degrees farenheit (850 C) will lead to plug insulator blistering or melting leading to pre-ignition/detonation. There is, generally, 150-200 degree farenheit spacing between heat-ranges. A richer A/F mixture will reduce cylinder temperatures, a lean A/F mixture will raise cylinder temperatures, increased boost will elevate temperature, denser (colder) air will make A/F ratio leaner, humid air will tend to make A/F ratio richer, a 10deg change in timing (advance) adds approximately 150-200 degrees farenheit. Remember anything increasing compression (or the final compression ratio) will result in elevation of cylinder temperatures.
The general rule of thumb is one heat-range colder for every 75-100 hp increase.
Also, when you install a colder plug, you should also back the timing off a bit, increase fuel enrichment, and increase octane. As the boost goes up, you'll often have to reduce the plug gap as well to keep from "blowing the spark out" with higher boost.
Densos look very similar to NGKs. But the densos seem to last longer. Not long enough for the money you pay but longer anyhow