What Spark Plugs you running?
Race Director
Joined: Jan 2008
Posts: 16,028
Likes: 170
From: oregon
delco 41-110 or ngk tr5ix
there was a service bulletin that replaced thet tr55 with the tr5
the only difference is the 41-110 and tr5 are gapped at .040 not .050, long story short larger gaps are more likely to detonate but usually make more power. smaller is the reverse
there was a service bulletin that replaced thet tr55 with the tr5
the only difference is the 41-110 and tr5 are gapped at .040 not .050, long story short larger gaps are more likely to detonate but usually make more power. smaller is the reverse
Race Director
Joined: Jan 2008
Posts: 16,028
Likes: 170
From: oregon
copper is the best conductor of electricity but it also wears the fastest. if you change your plugs every 15k miles use copper. if you want to go 50k miles or even 100k use iridium
Melting Slicks
Joined: Jun 2012
Posts: 3,163
Likes: 6
From: Oceanside California
The idea behind iridium is that they last a long time. I use copper as I change them often for best performance. Im using the TR55's. Car runs great with them and as stated, the larger gap you can get away with will increase power.
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Safety Car
Joined: Jul 2005
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From: Jackson Tn
St. Jude Donor '06-'07-'08-'09
Safety Car
Joined: Apr 2007
Posts: 3,582
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From: SoCal CA
Actually silver is but there are no silver plugs since they would be super expensive. Copper is the way to go for performance and it lasts much longer then 15k miles. My copper Autolite 103's after 30k mi still looked good. I checked the gap every 10-15k mi.
Race Director
Joined: Jan 2008
Posts: 16,028
Likes: 170
From: oregon
high rpm track time seems to really shorten plug life
Last edited by racebum; Apr 10, 2013 at 06:38 PM.
Safety Car
Joined: Apr 2007
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From: SoCal CA
Melting Slicks
Joined: Nov 2008
Posts: 2,938
Likes: 65
From: Rochester Hills MI
Does the number of outer electrodes matter at all? I'm running the acdelco irridiums, but there are plenty of plugs out there with 2-4 outer electrodes. I never understood this. You see the platinums with 4 electrodes, but I've never seen irridiums with 4. What gives? I know it increases longevity of the outer electrodes, but why don't they do it for irridiums?
Last edited by SaberD; Apr 11, 2013 at 11:44 AM.
Melting Slicks
Joined: Jun 2012
Posts: 3,163
Likes: 6
From: Oceanside California
Does the number of outer electrodes matter at all? I'm running the acdelco irridiums, but there are plenty of plugs out there with 2-4 outer electrodes. I never understood this. You see the platinums with 4 electrodes, but I've never seen irridiums with 4. What gives? I know it increases longevity of the outer electrodes, but why don't they do it for irridiums?
In an iridium plug, the tip is so small that only one electrode can be lead to it. The design doesn't allow for multiple electrodes.
If longevity is your goal, I'd choose iridium over a multiple electrode plug any day. But IMO copper plugs are still the best and just need changed every 30-40K miles.
Melting Slicks
Joined: Jun 2001
Posts: 2,565
Likes: 2
From: Chicagoland Illinois