Thrasher245

iTrader: (5)

With my mods below what heat range/plug should I use? I have autolight 106 in right now, are those stock heat range? I was thinking about the TR6s but what heat range is that? A step colder? I pulled out #7 plug the other day and the electrode is totally gone, even though it still would idle fine and not miss or anything. So im guessing it preignited, running lean or something so I think I need a colder plug but dont know what to go with. Any ideas would be great. Thanks.

Also how do you know what gap to use. Stock is .060. Ive read people run different gaps, so how do you know what you should be using givin your car specs?

sickss228

iTrader: (27)

TR-55's gapped at .050-.055. Sound like your car is running lean did you check all the other plugs? For a N/A motor w/ your mods you shouldnt have to go to a one step colder plug. Maybe someone else will chime in.

conan

iTrader: (5)

Go with the TR55's the TR6's are a colder plug. I ran the tr55 when I was N/A and had a nice grey burn on all of them. TR6's for spray or a blower application.

silverTA2002

iTrader: (1)

basically, from what I've read, ls1tech guys will tell you TR55 for N/A.

The spark plug manufacturers will tell you one step colder for each 100hp you add (n/a OR nitrous, doesn't matter).

Every car is different, but if I were you, you're obviously "reading" your spark plugs. From what you've "read" you need a colder plug. I'd run a TR6.

The spark plug manufacturers also say to "err on the side of colder" is better. Plus, the nitrous guys run around on TR6 plugs on a stock motor all day long with no problems. They only use nitrous occasionally.

ssheets

iTrader: (1)

I'm no expert, but that's why I contacted NGK. They told me to run a TR6 when making 100hp over stock. He said it didn't matter if that 100hp came from a bottle, blower or high compression and a nice cam.

So that's straight from NGK tech support FWIW

Thrasher245

iTrader: (5)

Thanks for the info. Ill post a pic of my plug later tonight, it looks very interesting. Why is it that only the one completely desenigrate, and all the rest look perfectly fine? Why do alot of people set the gap slightly smaller than stock? Im thinking I really need to get on my guys back to get me a tune done then run the tr55s. By looking at the plug I need the tr6 I think, but thats only because I havent had a decent tune yet. But any more info would be awsome. Thanks.

ssheets

iTrader: (1)

I wonder if a dirty (or bad) injector could cause the one cylinder to lean out???

ninobrn99

iTrader: (8)

ws6firebirdTA00 is making 415-430 and he runs the t6's. Im going to be swapping to them also.

sickss228

iTrader: (27)

I make 480 rwhp and still run the TR 55's. I still dont see why you have to run colder plugs if you start making decent power Also like I said before are all your plugs the same? If not than you have to start looking at fuel and air delivery to that cylinder, not just going one step colder and hoping that will solve the problem.

MeentSS02

iTrader: (11)

It's a matter of getting the heat out of the combustion chamber effectively, without removing so much heat that the plug fouls. If the TR55s work, great. You really just have to pull the plugs frequently and see what they are telling you. Kinda like a Ouija board.

sickss228

iTrader: (27)

Most definatley

silverTA2002

iTrader: (1)

I don't understand either, but when you ask the guys who make the spark plugs, that's what they tell you.

Some quotes from ngksparkplugs.com:

The spark plug has two primary functions:

To ignite the air/fuel mixture
To remove heat from the combustion chamber



Below is a list of some of the possible external influences on a spark plug's operating temperatures. The following symptoms or conditions may have an effect on the actual temperature of the spark plug. The spark plug cannot create these conditions, but it must be able to cope with the levels of heat...if not, the performance will suffer and engine damage can occur.

Air/Fuel Mixtures seriously affect engine performance and spark plug operating temperatures.

Rich air/fuel mixtures cause tip temperature to drop, causing fouling and poor driveability
Lean air/fuel mixtures cause plug tip and cylinder temperature to increase, resulting in pre-ignition, detonation, and possibly serious spark plug and engine damage
It is important to read spark plugs many times during the tuning process to achieve the optimum air/ fuel mixture
Higher Compression Ratios/Forced Induction will elevate spark plug tip and in-cylinder temperatures

Compression can be increased by performing any one of the following modifications:

a) reducing combustion chamber volume (i.e.: domed pistons, smaller chamber heads, mill ing heads, etc.)

b) adding forced induction (Nitrous, Turbocharging or Supercharging)

c) camshaft change
As compression increases, a colder heat range plug, higher fuel octane, and careful attention to igni-tion timing and air/fuel ratios are necessary. Failure to select a colder spark plug can lead to spark plug/engine damage
Advancing Ignition Timing

Advancing ignition timing by 10° causes tip temperature to increase by approx. 70°-100° C
Engine Speed and Load

Increases in firing-end temperature are proportional to engine speed and load. When traveling at a consistent high rate of speed, or carrying/pushing very heavy loads, a colder heat range spark plug should be installed
Ambient Air Temperature

As air temperature falls, air density/air volume becomes greater, resulting in leaner air/fuel mixtures.
This creates higher cylinder pressures/temperatures and causes an increase in the spark plug's tip temperature. So, fuel delivery should be increased.
As temperature increases, air density decreases, as does intake volume, and fuel delivery should be decreased
Humidity

As humidity increases, air intake volume decreases
Result is lower combustion pressures and temperatures, causing a decrease in the spark plug's tem-perature and a reduction in available power.
Air/fuel mixture should be leaner, depending upon ambient temperature.
Barometric Pressure/Altitude

Also affects the spark plug's tip temperature
The higher the altitude, the lower cylinder pressure becomes. As the cylinder temperature de-creases, so does the plug tip temperature
Many mechanics attempt to "chase" tuning by changing spark plug heat ranges
The real answer is to adjust jetting or air/fuel mixtures in an effort to put more air back into the en-gine

ssheets

iTrader: (1)

Nice reply SilverTa.

I've been told how valves do the same job. A vlave job for a street motor sacrifices some flow for better thermal transfer and hence longer life. A full blown race valve job has less seat area and less thermal transfer, but better flow for a shorter life.

Good stuff on the plugs though.

Thrasher245

iTrader: (5)

I went with the TR55s gap at 55. Installed em all in under an hour! Ive read alot of people take up to 8 hours??

Thanks for all the info guys.

silverTA2002

iTrader: (1)

FWIW I just finished installing TR6 plugs about 10 minutes ago. My TR55 plugs were visually too hot. And the gap had widened to .065 from .055 on all the plugs.

Install took me 2 hours, and I cracked one of the plugs, so #8 will have to be installed another day.

silverTA2002

iTrader: (1)

I should note two things.

1. The car ran fine on the TR55 plugs.

2. I'm over 11:1 compression.