which plugs are best to use

**RARON455** · 03-14-2008, 07:08 PM

I am going to be replacing the plugs and O2 sensors in my car and have been reading alot of the post on the plug subject and alot of guys are running NGK tr55 I have seen mention of TR55 IX which is a irridium plug, should I buy the irridium plug, I will if I need it, or just the standard tr55? The only other plug I would consider is the Delco replacement. ALSO I am going to be replacing the O2 sensors,(bad fuel milage) should I run the bosch ones from autozone, or buy ones from my dealer, I have also heard of using corvette sensors, whats up? I appreciate the help and your experiences fellas, I dont want to be changing the plugs that often they dont look to be much fun.

My car is a 98 T/A volant intake, cheap no name catback on it when purchased, I will be putting headers on it this summer and a better cat back. No spray ever, just a intake and exhaust.

**Firebirdjones** · 03-15-2008, 03:41 PM

We had some recent experience on the dyno with spark plugs I'll share.

Not a fan of NGK's right off the bat. I don't care for the screw on tips, reminds me of tractor plugs. And after running for a while they always seem to loosen up. But the real issues........

Running the factory ACdelcos at first, and we wanted to try a colder plug. Well the first thing we ran into was the fact that ACdelco no longer lists a heat range for the LS plugs, just a series of letters,,,,with that said we really had no idea what we had for a starting point,,,,so we had to cross them over to an NGK equivilent heat range, that turned out to be the TR55's,,,strangely enough, the cylinder temps increased slightly on what is supposed to be the same heat range.

Keeping in mind the ACdelco plugs are already a hot plug.....

NGK's part number increases for colder heat ranges (go figure

) but they are made in Japan, what do ya expect.

So we shoved in a set of TR6's and cylinder temps still weren't near the ACdelco's.....

We came to the conclusion the NGK's are just a damn hot running plug,,,,could cause detonation issues if tuning isn't right, so we pitched these in the trash and took a different approach. Back at the store crossing over the stock ACdelco plugs to an autolight number.

Autolights actually had a heat range number to work with,,,,these plugs are made in the good ole US of A and the numbers actually work as they should, higher number = hotter plug,,,,lower number = colder plug.

With that said,,,,the AC plug crosses to an APP104,,,,,sticking these in the engine and cylinder temps were nearly on par with the AC's.

Dropping to the APP103's saw the cylinder temps lower a bit,,,,finally we saw what we were looking for. With this found I came home and yanked the NGK's out of my car and stuck in a set of Autolight APP103's.
Thought I'd give these a try for a while and see how they work and do some logging and tuning. If they don't work out for some reason I may go back to the AC's, but no more NGK's for me.

On the 02 sensors here's what I also recently did......

Had a fairly new set of ACdelco 02's in mine,,,and one of them crapped out on me after about 6,000 miles or so. Rather than stick another set of ACdelco's in there, and talking to a friend from the board here, I decided to give a set of the Bosch sensors a shot. Since they have been installed I've done minimal driving due to weather conditions, but so far so good,,,,again another experiment so to speak,,,we are trying to find something that is happy in long tube headers,,,,since headers sometimes cause slow response and heating codes. So far the Bosch have been fine, even with this cold weather driving and longer warm up periods.

The corvette sensors you referred to are simply sensors with a much longer harness so the extension harnesses for long tube headers are no longer needed.

Hope this helps some.

**Mr. Luos** · 03-15-2008, 05:48 PM

NGK TR55's.

**RARON455** · 03-15-2008, 06:52 PM

great info.

**Fury_786** · 03-15-2008, 07:13 PM

TR6's

and nitrous...

**GatorSS** · 03-15-2008, 08:06 PM

My original plugs were Denso Iridium. I experimented with E3 plugs for a little while, but changed back to a new set of Denso Iridiums and haven't looked back since.

**02blkws6** · 03-16-2008, 12:10 PM

Autolite 103 FTW

**Jays00ss** · 03-16-2008, 12:19 PM

AC delco Iradiums

**Jays00ss** · 03-16-2008, 12:20 PM

Originally Posted by Mr. Luos

NGK TR55's.

You run Jap parts on Slowass

**CamaroFan71** · 03-16-2008, 06:02 PM

Ive always run Bosch plugs in most things I drive. Always had great experiences with them and plan on using them on my next tune-up.

**Mr. Luos** · 03-16-2008, 06:06 PM

Originally Posted by Jays00ss

You run Jap parts on Slowass

NGK TR6's are what I run.

Found them to work the best. LSx likes heat.

**Fury_786** · 03-16-2008, 06:11 PM

**JoshieDoom** · 03-16-2008, 07:48 PM

Just like everything else ngk is made in the us.. just maybe a jap owned company.. like i work for

1966 - NGK Spark Plugs (USA), Inc. was established as a subsidiary of NGK Spark Plug Co, Ltd., of Japan ( www.ngkntk.co.jp ). Its purpose was to establish and develop a market in the United States for NGK spark plugs and NTK ceramic products.

1976 - NGK Spark Plugs Mfg. (USA), Inc. was established to assemble spark plugs in the United States with construction of our Irvine, California facility completed in 1981.

**Y2KPewterSS** · 03-16-2008, 08:45 PM

http://www.ls1.com/forums/showthread.php?t=31657

**robcas47** · 03-17-2008, 12:07 AM

Was thinking about running the E3 plugs. anyone have any experience with these.

**JoshieDoom** · 03-17-2008, 01:07 AM

heard they were BS.. HOOAH btw

**jad628** · 03-17-2008, 03:25 AM

Originally Posted by robcas47

Was thinking about running the E3 plugs. anyone have any experience with these.

Nope, but I've run AC-Delco Iridiums for some time now and they work well. There was a very slight increase in mpg with no other changes, but a fresh set of other plugs could have done the same thing. I'd recommend Iridiums just for long life if nothing else.

All the way troop!!! I lived off Ringgold Rd. (near Grandpa's) in Clarksvegas when I was stationed with the 101st (early to mid-80's).

Take care, Air Assault.

**Firebirdjones** · 03-17-2008, 03:53 AM

Originally Posted by JoshieDoom

Just like everything else ngk is made in the us.. just maybe a jap owned company.. like i work for

1966 - NGK Spark Plugs (USA), Inc. was established as a subsidiary of NGK Spark Plug Co, Ltd., of Japan ( www.ngkntk.co.jp ). Its purpose was to establish and develop a market in the United States for NGK spark plugs and NTK ceramic products.

1976 - NGK Spark Plugs Mfg. (USA), Inc. was established to assemble spark plugs in the United States with construction of our Irvine, California facility completed in 1981.

Oh common now,,,,are you saying as long as a Jap owned company is in the US then it's okay????? That techincally still doesn't make it a US product,,,,where do ya think the money goes or the material comes from????

There are a ton of NGK lovers with LS engines, why???? I don't know. Probably alot of hype early on and alot of impressionable kids.
But all we found is they belonged in the trash.
If ACdelco actually made some heat ranges to go by I would probably go back to using them. For now Autolites do the trick and work as advertised.

Edit: Maybe I should clearify,,,,when referring to heat ranges on the AC's,,,it was the LS motors I have a problem with since there is not a number to coincide,,,,but on the older iron AC does list a heat range and they do work as advertised, I still use them on the old stuff.
For instance I'll use a common plug like,,,,,,,,,R44TS the good old fashion easy to understand numbers

R = Resistor
44 = Heat Range
T= Taper seat (small plug without gasket for the old gear heads here) 5/8 plug
S = Extended Tip (which means the electrode/groundstrap a more exposed)

Without the "T" in the part number then you have the larger 13/16 plug with a gasket.

You can move from a 43 heat range all the way up to a 46 (higher number meaning hotter)

On the LS motors you have none of this,,,,just a series of letters, and none of the letters give a definition for a heat range in any AC book. So how hot is it? Thats anyones guess. All we could do is monitor cylinder temps on the DTS and look for changes. We didn't find any with NGK's, even the ones that are "supposed" to be colder.

Now most tuners will tell you to install a colder plug for a more aggressive tune,,,,or if you run nitrous going down a heat range or two on the plugs is recommended. This is to help fight off detonation to some degree,,,,what scares me is the NGK's showed no difference.
These are just things we recently found and thought I'd share since someone was asking. Use your own judgement.