[Z06] TR5 Spark Plug Gap
Thread Starter
Pro
Joined: Aug 2011
Posts: 522
Likes: 45
From: Thousand Oaks Ca
TR5 Spark Plug Gap
I'm putting on Headers on my Z06. I'm changing my plug wires to MSD Wires and i'm installing NGK TR5 Plugs. I've been reading about what gap i should have them at and i'm getting all kinds of answers from. 40-.50.
What should i gap the plugs to?
What should i gap the plugs to?
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
There was a TSB years ago (Dec 12, 2003) from AC Delco (TSB_03D-J-17) to all distributors and jobbers of spark plugs that reduce the gap from 0.060" to 0.040". Google TSB_03D-J-17 and you'll probably find it.
The new NGK TR-5 plugs should come gaped from the factory at 0.040".
The NGK TR-55 plugs still come gaped from the factory at 0.060" ... BUT, they are no longer specified by NGK as the correct plug for the LSx engines (due to the TSB I mentioned above).
The new NGK TR-5 plugs should come gaped from the factory at 0.040".
The NGK TR-55 plugs still come gaped from the factory at 0.060" ... BUT, they are no longer specified by NGK as the correct plug for the LSx engines (due to the TSB I mentioned above).
Last edited by ZeeOSix; Sep 7, 2012 at 05:23 PM.
Burning Brakes
Joined: Sep 2010
Posts: 1,137
Likes: 4
From: Indianapolis Indiana
St. Jude Donor '13, '15, ‘18, '21
There was a TSB years ago (Dec 12, 2003) from AC Delco (TSB_03D-J-17) to all distributors and jobbers of spark plugs that reduce the gap from 0.060" to 0.040". Google TSB_03D-J-17 and you'll probably find it.
The new NGK TR-5 plugs should come gaped from the factory at 0.040".
The NGK TR-55 plugs still come gaped from the factory at 0.060" ... BUT, they are no longer specified by NGK as the correct plug for the LSx engines (due to the TSB I mentioned above).
The new NGK TR-5 plugs should come gaped from the factory at 0.040".
The NGK TR-55 plugs still come gaped from the factory at 0.060" ... BUT, they are no longer specified by NGK as the correct plug for the LSx engines (due to the TSB I mentioned above).
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
The only difference between the TR-5 and TR-55 is the gap from the factory. Everything else about them is identical, as I found out by a conversation with the NGK Tech Dept when I was researching new plugs.
TR-5 = 0.040" gap from factory
TR-55 = 0.060" gap from factory
Some guys still run a 0.060" gap.
Buy the plug based on the gap you want to run. It's better to do that then get the wrong one and re-gap the plug because it puts stress on the negative electrode. I'd rather not bend it around if I don't have to.
TR-5 = 0.040" gap from factory
TR-55 = 0.060" gap from factory
Some guys still run a 0.060" gap.
Buy the plug based on the gap you want to run. It's better to do that then get the wrong one and re-gap the plug because it puts stress on the negative electrode. I'd rather not bend it around if I don't have to.
Instructor
Joined: Oct 2012
Posts: 134
Likes: 0
From: Fl
I know this is an old thread but I have a question about the TR5's.
The site corvettecentral.com claims their set of NGK iridium tr5s are pregapped at .50, is that a mistake? If they are in reality gapped at 50 would that be bad if youre stock except for exhaust?
The site corvettecentral.com claims their set of NGK iridium tr5s are pregapped at .50, is that a mistake? If they are in reality gapped at 50 would that be bad if youre stock except for exhaust?
