What Spark Plug Gap?
Thread Starter
Burning Brakes
Joined: Aug 2002
Posts: 949
Likes: 1
From: Cary Il
What Spark Plug Gap?
There seems to be some controversy over what gap to use on the C5 after market plugs being used i.e. NGK, Champion, etc. is it .35 - .45 - .55 - .60.
The tech at NGK told me .55 the chevy engine builders feel .35 - .45.
So what do you guys think!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!
JR
The tech at NGK told me .55 the chevy engine builders feel .35 - .45.
So what do you guys think!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!
JR
Safety Car
Joined: Jan 2000
Posts: 4,965
Likes: 0
From: Midlothian, VA
Re: What Spark Plug Gap? (TexasRedY2K)
.060 for stock gap plugs, for every 50 HP OVER stock HP level, whether it's nitrous, N/A or FI power, decrease the gap by 0.004 per 50 HP OVER stock.
So 150 Nitrous shot on a STOCK (showroom stock) car would be a decrease of 0.012 = 0.048 gap. If you added 50 HP in N/A mods and 100 in Nitrous, 0.004 x 3 (3 multiples of 50 HP) = 0.012 decrease in gap = 0.048 gap size.
So 150 Nitrous shot on a STOCK (showroom stock) car would be a decrease of 0.012 = 0.048 gap. If you added 50 HP in N/A mods and 100 in Nitrous, 0.004 x 3 (3 multiples of 50 HP) = 0.012 decrease in gap = 0.048 gap size.
Burning Brakes
Joined: Jun 2002
Posts: 767
Likes: 1
From: Noble OK
Re: What Spark Plug Gap? (carpe dm)
I run the stock NGK TR 55's gap of .057, but after reading about plugs on http://ls1.com/index_faq.html#601 will probably try the .050 gap they recommend. Check out the article pretty informative! :yesnod:
Thread Starter
Burning Brakes
Joined: Aug 2002
Posts: 949
Likes: 1
From: Cary Il
Re: What Spark Plug Gap? (JR-CRUZN-C5)
Here is a bit more fuel for the fire!!
NGK says .55, Vinci Hi-Performance says .50, Finish Line Performance says .45, Opel engine builders say .35 and on and on and on!!!!!!!!!
Plugs to consider: NGK TR6 @ .55, Champion RS12YC @ .50
JR :blueangel:
[Modified by JR-CRUZN-C5, 2:33 PM 9/11/2002]
NGK says .55, Vinci Hi-Performance says .50, Finish Line Performance says .45, Opel engine builders say .35 and on and on and on!!!!!!!!!
Plugs to consider: NGK TR6 @ .55, Champion RS12YC @ .50
JR :blueangel:
[Modified by JR-CRUZN-C5, 2:33 PM 9/11/2002]
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Burning Brakes
Joined: Jun 2002
Posts: 767
Likes: 1
From: Noble OK
Re: What Spark Plug Gap? (JR-CRUZN-C5)
JR-CRUZN-C5, it has been stated that NGK does not recommend changing the stock gap of their plugs by more than plus or minus .010, they recommend you change which plug you use instead. Read posted article above in my prior post at ls1.com.
Burning Brakes
Joined: Jun 2002
Posts: 767
Likes: 1
From: Noble OK
Re: What Spark Plug Gap? (JR-CRUZN-C5)
Just telling you what I read, bro. Why does he want you to run a colder plug? I plan on changing plugs next year back to same NGK plugs but gapped a little tighter at .050 . One of the other guys said he was getting timing retard until he closed the gap and then it went away.
Thread Starter
Burning Brakes
Joined: Aug 2002
Posts: 949
Likes: 1
From: Cary Il
Re: What Spark Plug Gap? (Xssesive)
My C5 is over at FLP getting Vinci Heads & Cam installed I tend to like what they say about the plug gap issue (.045) although Roger Vinci is running a 9 sec. 06 using .050 with N02. They are going to dyno my car with amoung other things a .055 gap and TR6 plugs. (I am currently running the Champions gapped at .050 with no problems!
JR
JR
Drifting
Joined: Nov 2000
Posts: 1,456
Likes: 1
From: Allen TX
Re: What Spark Plug Gap? (Xssesive)
Just telling you what I read, bro. Why does he want you to run a colder plug? I plan on changing plugs next year back to same NGK plugs but gapped a little tighter at .050 . One of the other guys said he was getting timing retard until he closed the gap and then it went away.
Drifting
Joined: Oct 1999
Posts: 1,576
Likes: 0
From: Austin TX
Re: What Spark Plug Gap? (C5Noir)
What is the theory behind slimming the gap .004 per 50 hp? What is the gain? Knock control? Burn?
I want to do this now that I have the S/C, but pulling the plugs to do it, ugh.
F
I want to do this now that I have the S/C, but pulling the plugs to do it, ugh.
F
