Celica Forums General Discussion General Spark plugs

When do you replace your spark plugs? 30k, 60k.

https://celicahobby.com/tech/tsb2/ARTICLE_MAINT_NORMAL_60K.pdf

This is the 60K schedule.

I concur.

when do "I"? Clean them every 3000 or before every race if I'm racing during that season. Replace every 9000. But that's just me.

They are Iridium aren't they? Those suckers are good for a minimim 60,000 miles. The only time you would fowl them is if you are chipped & running rich.

That was for what I would do with the stock ones. yeah I know, but I'm obsessive about Performance so I pull them often and make sure they are clean. Just in case anyone is curious about the Denso Iridiums, I felt about a 5 hp increase after popping them in (don't ask if I dynoed). The cost is $13.99 per plug.

Is it ok to run Bosch Plat 4 plugs?

sure, but Densos are better for N/A IMO.

Check the left side of the cylinder head there is a warning label specifically requesting Iridium plugs only...at least there is on my motor...you can run the Bosch but there maybe a Performance issue/durability issue.

...since platinum is a colder plug than iridium I would say a Performance issue for N/A cars. But if that person insists on running low octane gas like 89, the colder platinum plugs could actually be a blessing, being less likely to cause detonation, which is always bad.

And I should state to err on the side of caution, that if one puts nitrous or a Turbo on your car, it would be best to ignore this warning and go with colder plugs by several heat ranges to be less likely to provoke detonation.

I put the plat plugs in a stock 2000 GT, and there are no plans to do any engine mods to it. Should I pull these back out and put in iridiums?

So we (GT owners) do not need Iriudium Plugs...I am kinda confused so try and bare with me...

If I run regular octane (cheapo stuff) then a Platinum Plug is fine (since it is "colder" meaning it can endure lower temperatures)
but if..
I run an Iridium plug ("hotter" meaning it can enure high temperatures) it is over kill for stock unless I have NO2 / a Turbo / or both, where engine temps are hotter and the higher temp would be a "normal" operation for these mods.

Is this what you are saying...or am I reversing something... (Platinum < Iriudium) for temp rating...I hope this makes sense...anyway I am out of the office in a bit but I'll be back around later tonight.

Oh one more thought, since the GT is a high reving engine for its power band then wouldnt' the Iridiums be better for longer life and less chance of detonation.

Sorry bout the length...I am doing some Calculus III while thinking here

calculus III ?!?!? what fun !

www.sparkplugs.com [sparkplugs.com]

^^sorry I don't have time to explain now...gotta run some errands and will back later tonight if you're up hehe.

i meant cal II , but even still shitty...cal III is next semester

Thanks

...aside from some terminology mix ups I basically got it. I am sticking with the Denso Iridiums

yeah I checked out that site (with a good name for business!) and like the price on the Denso Iridiums: $11.99 but that's probably without shipping right? Autozone charged me $13.99/plug but I just had to pay tax.

You should get better Performance with the iridiums, especially denso iridiums, over the platinum. Does anyone know the specs on the stock iridiums, like diameter of center electrode, etc? I pulled those out a long time ago when I didn't know any better and went with platinum. It would be funny if the stock iridiums were actually made by denso, but I'm not sure if Toyota would go that lavish stock.

Denso Iridium plug 3324 SK16R11 0.044 $9.35 <---These came stock in my car...I wish I had seen sparkplugs.com earlier this site has a decent prices...my local A/Z didn't even have this plug listed in thier computer.

What's interesting is those numbers don't match the part numbers on sparkplugs.com for the premium class (and more expensive) denso iridiums. Perhaps they changed in 4 years and improved them? Or just simply changed the numbering?

There are two grades of denso iridium available on sparkplugs.com: super and premium with premium being better. I'd guess Toyota put the super or something close to that at the time in the stock car.