Spark Plug type and Gap for boost
Thread Starter
Pro
Joined: Nov 2011
Posts: 592
Likes: 13
From: Austin Texas
Spark Plug type and Gap for boost
So I have searched this as much as possible and it seems like most people have a different opinion on copper vs iridium and what gap people run. Has anyone directly tested a copper plug then switched to iridium? Any difference? Im running copper currently but feel like the engine could run a little smoother.
I know is highly dependent on the engine and compression but I figured a reference post may help.
Engine: LS7 10.5:1 compression
Fuel Type: 93 (10psi) or E85 (high boost)
Spark plug type: B8EFS
Material: Copper
GAP: .022
FI Type: Turbo
Boost: 22 PSI
Meth: No
N20: No
HP: 800whp (93) 1100whp (E85)
I know is highly dependent on the engine and compression but I figured a reference post may help.
Engine: LS7 10.5:1 compression
Fuel Type: 93 (10psi) or E85 (high boost)
Spark plug type: B8EFS
Material: Copper
GAP: .022
FI Type: Turbo
Boost: 22 PSI
Meth: No
N20: No
HP: 800whp (93) 1100whp (E85)
Team Owner
Joined: Nov 2007
Posts: 24,035
Likes: 2,342
From: Gilbert AZ
I like iridiums. Didn't notice a difference, as our cars never run high high boost. Was watching a friend tune an EVO at 45-50psi, and copper plugs kept missing. Swapped to iridiums, and all good. He said anything that was seeing 40+ psi needed the iridiums. So while I don't think there is much of any difference on a LS platform running <30psi, it convinced me that iridium works better.
Le Mans Master
Joined: Apr 2011
Posts: 7,821
Likes: 412
From: Montreal
St. Jude Donor '13
Get flack every time I say this but I'll give it one more shot. Do yourself a favour and try silver. Runs better, lasts longer, and conducts better.
http://www.briskusa.com/silver_spark...ng_spark_plugs
http://www.briskusa.com/silver_spark...ng_spark_plugs
Team Owner
Joined: Nov 2007
Posts: 24,035
Likes: 2,342
From: Gilbert AZ
Melting Slicks
Joined: Feb 2013
Posts: 2,034
Likes: 111
I've run both copper NGK 7s and 8s and didn't notice a difference in the way my car runs on the street. 900whp procharged 427 with 9.75:1 compression on 91 pump gas and methanol.
heard some guys having issues with iridium holding heat like glow plug on yellowbullet? could have been urban myth, but I usually pull plugs everytime I do oil and check them so have run a few different kinds and never really noticed a difference on this car for 7, 8, ngk, autolite, etc all seem to be about the same.
heard some guys having issues with iridium holding heat like glow plug on yellowbullet? could have been urban myth, but I usually pull plugs everytime I do oil and check them so have run a few different kinds and never really noticed a difference on this car for 7, 8, ngk, autolite, etc all seem to be about the same.
Last edited by neverstop; Jun 29, 2016 at 10:07 PM.
