I was checking two Autoparts stores if they had them and both of them warned me that this car required Platinum Plugs... I know that the TR55's are not platinum unless I get the Irridiums. Is this something I should seriously worry about or will they still be okay? Will they still fire just as well as the Delco Plat's? I'm not running any spray or forced induction... Also, my local Auto Parts store only had TR5's so I purchased them in substitute for TR55's. Supposedly they're a heatrange higher than TR55's... Is this going to cause anything bad? Should I take these back and just get platinums?

Edit: Did alittle searching and it appears the only noticable difference is the gap between the TR5 and TR55's is the gap. If thats so then can't I just re gap them to 0.50? Or is the heat range also something to be concerned over?

 

stock gap for the ls1 is .060"....

the ngk's are perfectly fine. these cars do not "require" platnum. GM put them in there to work the whole..."100k mile service" thing.

which is

on both my 96LT1 and 99LS1...the plugs came out at just over 40K miles...and on each car 4 or 8 plugs had lost the platnum puck...making the gap something like .080"!!!!

get the ngk and save some money....they'll be fine

 

Cool I feel much better now... However I didn't get the TR55's, I just have the TR5's... are these still okay? If I regap them to 0.060 will they be fine or do I need to reinvest in TR55's? I of course know that neither of these are going to gain me any HP, I just don't want any misfires...

 

NGK TR55's at .055 is what I'm running, been in the car over a year. Just visited www.ngksparkplugs.com Used to say .050 for 98 and .060 for 99-up for TR55's (3951). Now it says .044 for both. Know guys who run TR6's but the recommended gap is different, doublecheck the correct gap/application for TR5's, or if you even should be running them.

 

Which is what I'm trying to find out... They sold them for my car so I figured it would be okay?

 

Just get the right ones. tr55 part no. 3951

 

Heat range and gap are separate issues. I don't believe the TR5 / 55 / 6 has anything to do with the gap . It's what you said up front ... different heat range (the electrode will either stick further out, or will be deeper inset in the plug). I believe that guys who run nitrous or FI often use the TR6's (cooler plug) because the electrode is deeper in the plug and therefore the tip will stay cooler and won't burn off under the extreme heat/pressure. I'm only assuming that the TR5 is going to be the opposite, and the tip will be further out than the TR6 or TR55. All this means is the spark will be even closer to the A/F mix, and the tip will stay even cleaner than before (being more in the flame ... hence why it's considered a "hotter" plug). I don't see a problem with it really, but I don't know if I'm qualified to make that judgement call or not though??

 

Then I will go ahead and use them... if worse comes to worse I am only out $15 and a couple hours of my own labor...

 

AFAIK with the NGK plugs the first number is the heat range so a tr5 and a tr 55 would be the same heat range with a different gap. The tr6 is the next cooler plug and is used in FI builds to reduce the chance of detonation.
Again AFAIK the tr5 -tr6 are .035 or .040 gap and adding the extra 5 as in tr55 or tr65 denotes a .050 gap.
Gapping .035 or .040 plugs out to .050 or .055 is very difficult to do correctly and is senseless when all you have to do is get the right plugs.

 

All TR*(5) come with * heat range and .050 gap

Mike

 

So let me jump in here and throw a question in this mix.....

Difference between the Iridium and a Platinum plug are what exactly? Any reason to go with one over the other given the mods in my sig? I see people runnin the TR55's at different gaps, any real reason to go tighter than stock?


I need new plugs too

 

Cost.

They both have long plug lives. Iridium cost at least $7/plug. You can get good plats for ~$2.50/plug. Your call. If you go platinum, get plugs that are designed with out the puck. It'll be a little flat round piece on the electrode. Pucks are prone to falling off.

 

I'm not sure how this works but the Champion 103 plug, which is their step colder plug has quite a bit of the ceramic exposed compared to the NGK TR6. I know we are talking about different brands but the noticeable difference in exposed ceramic has me wondering.

 

Ok, I didn't know that was their system for classifying plugs. Good info .

 

NGK's are good plugs but i went with AC DELCO irridiums since NGK plugs are made in Japan... **** em