NGK tr55 to tr6 plug change on H/C LS1. Any difference? Yes..
#1
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Yesterday, I swapped out the NGK TR55 spark plugs gapped at .055 with one heat range colder NGK TR6 spark plugs gapped at .045, recommended by Fast Motorsports might I add (shop that previously tuned the car). Thought I'd share the very noticable difference it made incase this may be helpful to others. The plugs were in, and are in a 430whp & 400wtq 346ci LS1 C5 Corvette with ported heads, cam, intake, headers, etc. with a compression ratio of 10.8:1. First, the TR55 plugs I removed were gapped at .055, had approximately 7k miles of use and looked excellent when removed. With the TR55 plugs the engine made a not loud but noticeable ticking noise (what I always thought was valvetrain noise due to the Torquer v3 cam & dual springs) and the car surged very little at lower rpm's. With the TR6 plugs gapped at .045, the difference was very noticeable. The noticeable ticking noise is gone, completely. I mean with the engine running I had to concentrate to hear any ticking from the valvetrain. And the best part, there is no more bucking at lower rpm's. In lower gears I had to get rpm's down near 1k or under to get any bucking out of it. I'm surprised at the difference it made.
Last edited by R6cowboy; 06-19-2012 at 11:59 AM.
The following users liked this post:
98SSHARDTOP (05-03-2021)
#3
LS1Tech Administrator
iTrader: (3)
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,324
Likes: 0
Received 1,759 Likes
on
1,256 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech20year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Wonder if the ticking you heard was a loose plug allowing compression to escape the cylinder, or arching of some sort, or even a cracked/hairline defect in a plug causing a low rpm misfire; any of which could also cause the bucking. I've never had issues like that with TR55s, even with modified internals and more aggressive tuning than stock.
#4
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Wonder if the ticking you heard was a loose plug allowing compression to escape the cylinder, or arching of some sort, or even a cracked/hairline defect in a plug causing a low rpm misfire; any of which could also cause the bucking. I've never had issues like that with TR55s, even with modified internals and more aggressive tuning than stock.
If you ask me, it only makes sense the TR6 plugs are the better plug in my case. Concidering my engine has nearly a full point bump in compression and nearly 150hp over stock. I can't say TR6 plugs are always going to be better then TR55's, but this time in my case the TR6's definitely helped my car run better.
Last edited by R6cowboy; 06-19-2012 at 12:00 PM.
#5
LS1Tech Administrator
iTrader: (3)
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,324
Likes: 0
Received 1,759 Likes
on
1,256 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech20year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Idk RPM. None of the TR55 plugs were definitely not loose at all. I inspected all 8 plugs when I removed them, just habit on my part. Brandon, tuner & owner at Fast Motorsports, told me he recommends TR6 plugs w/ .45 gap for my application, now I know why. Also not long ago I coincidently came across a thread (either here on tech or on Corvette Forums) about some fellow who had a very similar set-up as mine and he also experienced a little surging/bucking. His thread mentioned when he changed TR55 plugs with TR6's, his surging pretty much completely went bye-bye.
If you ask me, it only makes sense the TR6 plugs are the better plug in my case. Concidering my engine has nearly a full point bump in compression and nearly 150hp over stock. I can't say TR6 plugs are always going to be better then TR55's, but this time in my case the TR6's definitely helped my car run better.
If you ask me, it only makes sense the TR6 plugs are the better plug in my case. Concidering my engine has nearly a full point bump in compression and nearly 150hp over stock. I can't say TR6 plugs are always going to be better then TR55's, but this time in my case the TR6's definitely helped my car run better.
![Cheers!!](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_cheers.gif)
#7
LS1Tech Administrator
iTrader: (3)
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,324
Likes: 0
Received 1,759 Likes
on
1,256 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech20year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
If there is anything wrong with your plugs, then stock heat range replacements should cure the issue for a stock engine. If not, then your problem likely lies elsewhere.
Trending Topics
#11
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Certain brands being better then others is debatable. The bottom line, NGK is a very good brand spark plug that will work well as long as the correct heat range plug is used and with the proper gap.
The following users liked this post:
fucter (05-03-2021)
#13
TECH Fanatic
iTrader: (5)
Join Date: Dec 2007
Location: Rochester, NY
Posts: 1,450
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I ran TR55's in my Z06 with the H/C setup and no issues. It was very quiet and no drivability issues. The only reason why I switched over to the TR6's was because I added a nitrous setup to the car.
#14
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Yesterday, I swapped out the NGK TR55 spark plugs gapped at .055 with one heat range colder NGK TR6 spark plugs gapped at .045, recommended by Fast Motorsports might I add (shop that previously tuned the car). Thought I'd share the very noticable difference it made incase this may be helpful to others. The plugs were in, and are in a 430whp & 400wtq 346ci LS1 C5 Corvette with ported heads, cam, intake, headers, etc. with a compression ratio of 10.8:1. First, the TR55 plugs I removed were gapped at .055, had approximately 7k miles of use and looked excellent when removed. With the TR55 plugs the engine made a not loud but noticeable ticking noise (what I always thought was valvetrain noise due to the Torquer v3 cam & dual springs) and the car surged very little at lower rpm's. With the TR6 plugs gapped at .045, the difference was very noticeable. The noticeable ticking noise is gone, completely. I mean with the engine running I had to concentrate to hear any ticking from the valvetrain. And the best part, there is no more bucking at lower rpm's. In lower gears I had to get rpm's down near 1k or under to get any bucking out of it. I'm surprised at the difference it made.
![](https://cimg5.ibsrv.net/gimg/ls1tech.com-vbulletin/2000x1504/20201114_132204_2f5e35f3f6392682cc4402fb75c725bbf5cfdc08.jpg)
The following users liked this post:
GoldrushCamaro (06-14-2023)