NGK Iridium plugs after a full year racing.

[Mike Puckett]

When I pulled my left side header off to finally fix a pesky exhaust leak I pulled out my NGK iridiums so I wouldn't accidentally break one. They look pretty good, nice and white with just a little color to them. The insulators are sooty from the header flange leak. This is after about 100 1/4 mi races, occasional errand running, and 2 interstate trips. I'll clean these up and put them back in. The header is at the machine shop getting resurfaced. I'll be putting in an extrude honed lower IC tube when it goes back together and with the extra weight loss I'm hoping it'll drop my best e.t. by a good 10th or more. My new Craftsman compressor with the air tools is really paying for itself. It sure makes it easier to work and shaved at least an hour off of the dissassembly time.

[Saber]

NGK is the only plug I run in any of my vehicles. V-powers in the NA stuff and I will run the Iridium in the sc when she is up and running.

[HSKR]

Good to see. I bought the Iridiums for my SC when I first got it and did a tune up. There was some talk that because the Iridium plugs didn't have any coating on the ground electrode they may not be able to hold up. But your pictures verify that they are good plugs and I made the right choice.

[thundercougar]

Ive been using NGK's in everything I own, I have a 1973 Yamaha tx750 that I rescued that sat in a garage for 20 years. I replaced the tank, cleaned the carbs, and changed the oil and batt and it started right up. It had the stock plugs which were ngk originals from the factory.

I hate all that bs that alot of "ford mechanics" talk about autolites being the best. The only thing an autolite is good for is using it in a flamethrower system. Cause you end up replacing the $1 plugs every other week.

[turbospeed]

do you have the p/n handy?

[David Neibert]

I've got the same plugs in my SC.

David

[HSKR]

Originally posted by turbospeed
do you have the p/n handy?

www.ngk.com and just look up a T-Bird SC. They are one of the cheaper places I have used, and very quick shipment. Most local parts stores I've tried never had any in stock.

[DamonSlowpokeBaumann]

I used denso iridiums IT20's 21psi and not flame blow out..Also didnt regap them//As they said nto too

[Mike Puckett]

The NGK # is TR55-1IX. I bought mine from NAPA for $6 ea. I like the V notch that Denso puts in the finger above the electrode but does it have the extended tip? The NGK has a smaller notch in it. My header is back so I'll put it back together this weekend.

[Bill McNeil]

I had those plugs in all year. They were doing okay until I ran some 91 octane fuel with them and burnt the end right off the one in cylinder #6 racing a new Nissan 350 Z.

I bought some Autolites I'm gonna try this year for comparison sake. Dalke has had relative success with them, as has Gary Kuhn. We'll see how it goes.

PS. This sounds pretty technical to me! :p ;)

[onequiksc]

The Denso Iridiums came standard in my GS400. There are people on ClubLexus that have pulled them at around 100k miles and the plugs still look great. I plan on swapping them out at the recommended 90k miles on my GS.

Not cheap, but worth the $$$.

[quick35th]

I've had the same plugs in my 35th now for a year. I put them on when I put on my 10% pulley to further prevent detonation. I baught them at Napa for like $6-8.

Shane

[BlackbirdSC]

I had Denso IT22's in mine. A little too cold for the weather this winter and they fouled after 25k miles. Although, I've had some tuning issues during that time. I'll clean them up and put them back in.

In the mean time, I put in a set of Autolite copper 2543s. (1 step colder than stock). Now, it pings horrendously bad even with 3 degrees less timing. So, the colder plugs do make a difference. I'm just wondering if I should switch to IT20s or the NGKs to keep it from fouling. Although then I might have detonation problems. Hmm..we'll see.

[DamonSlowpokeBaumann]

The IT 20's worked great in my car..And I didint regap them..With 21 psi and every bolt on imaginable..Give em a try as is..I pulled mine out after about 30,000 miles and still looked great