TR55 GAP setting from manufacturer
Thread Starter
Melting Slicks
Joined: May 2001
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From: Cockeysville Maryland
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Daytona Jam 1 Veteran
TR55 GAP setting from manufacturer
Do I have to change the GAP setting of my new TR55 plugs prior to install into my 1999 Coupe?
Thanks
Thanks
Team Owner
Joined: May 2001
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From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
At a MINIMUM, you should always check the gap of ANY plug prior to installation. Check to ensure they're set at .040 and install them.
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Racer
Joined: Jan 2013
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From: Mobile Alabama
Interesting. I have not installed the TR55's I just got, but I did pull one of my old plugs, and it's gap is also .060. I think the plugs in my car now are original. You would think if the .040 is the new recommended gap that they would come with that gap. I wonder why not? Now I am not sure what to do. What is the reason for the smaller gap? I just purchased my plugs along with MSD wires from a supporting vendor and they told me I do not need to change the gap. My car is stock, no engine mods.
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Interesting. I have not installed the TR55's I just got, but I did pull one of my old plugs, and it's gap is also .060. I think the plugs in my car now are original. You would think if the .040 is the new recommended gap that they would come with that gap. I wonder why not? Now I am not sure what to do. What is the reason for the smaller gap? I just purchased my plugs along with MSD wires from a supporting vendor and they told me I do not need to change the gap. My car is stock, no engine mods.
By application, the TR5 gapped at .040, is the plug NGK recommends for their V-power series plugs used in C5s (LS1/6).
Thread Starter
Melting Slicks
Joined: May 2001
Posts: 2,456
Likes: 8
From: Cockeysville Maryland
Cruise-In IV Veteran
Daytona Jam 1 Veteran
There seems to be confusion on this question by a number of folks.
There are TR5 plugs which apparently run a bit colder and are gapped at .040 and then there are TR55 plugs which are theoretically gapped at .060.
From what I have read there is also a range of gaps that will be tolerated for each plug.
My post was specifically about TR55 plugs although it seems most of the responses are related to TR5 plugs. Supposedly, except for the gap, they are the same.
Since there is this confusion I guess it's best for me to check the gap in the old plugs and make an executive decision on what gap to ensure the new TR55 plugs are set at.
My car has some engine modifications and is tuned so perhaps the existing plug gap would be best to identify and use.
Thank you for all of the responses!
There are TR5 plugs which apparently run a bit colder and are gapped at .040 and then there are TR55 plugs which are theoretically gapped at .060.
From what I have read there is also a range of gaps that will be tolerated for each plug.
My post was specifically about TR55 plugs although it seems most of the responses are related to TR5 plugs. Supposedly, except for the gap, they are the same.
Since there is this confusion I guess it's best for me to check the gap in the old plugs and make an executive decision on what gap to ensure the new TR55 plugs are set at.
My car has some engine modifications and is tuned so perhaps the existing plug gap would be best to identify and use.
Thank you for all of the responses!
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
The GM bulletin reduced the gap from 0.060 to 0.040 when going from the GM platinum plugs to the GM iridium plugs. Since the TR5 and TR55 are neither, not sure if they should stay at 0.060. My understanding is the large gap is to reduce certain emissions at partial throttle cruise.
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