gwj

I'm not going to comment on "best plug brand", whatever
works, works.
However I just want to point out that NGK recommends
not changing the gap more than .010, I believe.
I've seen people with basically stock setups that ran the
NGK TR6 plugs and were happy with them, but usually
with more frequent changes. A lot of those were '98s,
FWIW.
I've seen where some run the TR5s (smaller gap, same
heat range as TR55s).
I've run NGK TR55 plugs for 100,000 miles (no, not the
same set, LOL) and have gapped them anywhere between
.050 and the stock .059 with no difference on any data
I've scanned.
Big Geek probably has the right train of thought, here.....

BULLET99Z28

iTrader: (9)

I would run facry recommended plugs. look at my sig, my car runs awesome, 326 rwhp BEFORE the headers and ory, thats with ngk iridium. I put in delco iridium when installing the headers 1 month ago, and they look perfect, with no tune. unless u are nitrous or power added, stock iridium will work perfect, no knock, no detonation, don't listen to half these fools that say this or that, the factory spens millions to find out what works, stock will will work fine and last a long time naturally aspirated, copper plugs and such will wear out fast and not burn as completely, leaving h/p and mileage on the table. delco or comparative iridiums only 55 bucks at pep boys, works great 4 me.

FstBlkz28

iTrader: (13)

Our cars came with platinum coated delco's ... when I did my headers I switched to the Bosch Plat +4's, and there was no difference in throttle response or idle qualities. However, when I switched to the NGK tr55's, it was a night and day difference. I'm getting ready to put in my second set of tr55's here in the next day or two.

WS6FirebirdTA00

iTrader: (33)

-your power levels are a lot lower than 400, which means what works for you wont work for him

-when you add power or any mods at that you need to adjust the gap and heat range of a plug accordingly, so all that money gm spent is 100% worthless on a modded car. you should search before you post like this with so much information that is incorrect, so you dont look like a fool calling others a fool

-copper does burn completely where the hell did you hear that?

-the copper material wears faster AFAIK which is why it is recommended to change them sooner

-no power is left on the table with copper plugs

-13 bucks for a set of ngk coppers is cheap enough i can replace them more often and still save money. next time search before you make such a rediculous post

WS6FirebirdTA00

iTrader: (33)

yeah the +4 tend to run kinda shitty on our cars, ngk is the way to go,

hundreds of us wouldnt be running them if they didnt work...

Big Geek

iTrader: (2)

I thought some more about your dilemma and found time to sit down and give you a more direct answer. Here is what I have experienced with my car - I have run both the TR-6's and the 55's. The reason being is that I put the TR-'6s in it when I knew I was going to spray the car. As a side note I found that when I loaded the N/A tune back into the car I could actually put a little more timing in it through out the entire power band than with I could with the 55's being that the 6's are a colder plug. (I was just playing with the tune to see how it would run by leaving the 6’s in their all the time and creating a N/A tune around those plugs.) Allot of your dilemma in regards to the detonation is directly related to timing tune IMO. I found that I preferred the 55’s and a little less timing in a N/A tune.

That too is a hard question to answer as it is relative to the combination. Here is what I propose - Put the 6's back in it and set the gap between .058-.060 and monitor the KR through out the power band. If you find that you are getting detonation with the 6's then you definitely need to pull some timing out as anything colder than that plug is going to really run like crap. The reason I suggest the 6's to start with is that while your camshaft is larger than the stock one you did advance it by two degrees and without the cam card and some numbers crunching it is going to be hard to figure out how much it has raised your compression if any. By using the 6's to start with you can err on the side of caution. If you find your KR good and your O2's are fat then I would suggest leaving the timing were it is and switching to the 55's and repeat the process of monitoring throughout the RPM range again.

One last bit of rambling. My car is an 00 A4 with a 224/224 .558/.558 camshaft and I run the 55's at .058. At a given speed in O.D. with the converter locked I found that I would get detonation if I lightly accelerated without unlocking the converter. What I did was take out 2 degrees of timing in that area. If you cannot manipulate your timing tune yourself I would consider consulting with a tuner and let them know what you have found and see if they cannot help get your timing tables straight. Anyway I hope this may help you in some way. Happy holidays to you and yours.

Jim C.

Big Geek

iTrader: (2)

The problem with this suggestion is that one must take into consideration his overall combination. From what I can see it is different than yours. Camshafts and the way they are set up (-, TDC, +) can play a major role in sparkplug selection, on certain combinations even degreeing a cam can alter the heat range of a plug of some motors (Not usually a street motor though). A camshaft install may not seem like much of a difference but they can be. I am guessing that he has had new timing and fuel maps loaded into the PCM to match the camshaft. This is why I suggested either consulting with his tuner or if it is himself monitoring certain parameters in order to ascertain enough information to determine what it happening throughout the RPM range. I am not posting this to bust your ballz but more-so just to make a few points that you might have missed in the gents original post. Take care and happy holidays to you and yours.

Jim C.

TJ

iTrader: (10)

DO NOT RUN PLATINUM PLUGS.
stock or modified.
PERIOD.

Viper

iTrader: (6)

"Here is what I propose - Put the 6's back in it and set the gap between .058-.060 and monitor the KR through out the power band."

However, TR6's come gapped much lower ( .039 I think ), and it's against what all spark plug mfg's say; don't move the electrode more than +/- 10. FWIW I'm running TR5's at .042. TR5's are the same as TR55's with a tighter gap.

WS6FirebirdTA00

iTrader: (33)

0.004" tighter gap for every 50hp is the rule of thumb i heard, do you know any better way to get the gap right?

Mr_president

iTrader: (38)

is that -o.004 so if i decided to grab the 55 and put them in i should re gap them to .046 instaed of stock gap.050 or do i do .054 or .055 and would .060 be alittle on the high side??

WS6FirebirdTA00

iTrader: (33)

stock is 0.060 on the ls1, i would gap them at 0.055 for bolt ons and 0.045-0.050 for heads/cam depending on your power level

Mr_president

iTrader: (38)

what about just cam and bolt ons??? i as thinking .50 and then when i get my turbo set up im going to go back with tr6 but wasnt to sure on the gap with that with the 317 heads i will be putting on but thats not for another6 months

WS6FirebirdTA00

iTrader: (33)

you can put them at 0.050, thats fine