Iridium vs. Platinum plugs?
Iridium vs. Platinum plugs? Probably a stupid question, but are Iridium plugs worth the money over Platinums?
Fo a daily driven, non raced LS1, would a platinum plug, say a Autolite or Delco, be sufficient?
Thanks!
Fo a daily driven, non raced LS1, would a platinum plug, say a Autolite or Delco, be sufficient?
Thanks!
On The Tree
Joined: Dec 2001
Posts: 197
Likes: 0
No. Get copper's and change them more often.
I've never had platiniums that came out at even 60,000 miles with a decent plug gap. REgardless of material, plug gaps WILL change in 30,000 miles... the extra cost for plugs that "may do" is a waste when new copper plugs out perform them.
Iriidums have a worse problem... smaller electrodes blow out easier. My recent high-compression build was dropping cylinders like crazy with the irridiums and finally idled fine with TR55's. Had to pull those to replace them with TR5's gapped to 0.040" for high rpm stability. Going to Autolite Racing AR103's with a cut back electrode though. This is a LT1 though... YMMV.
Get the copper tops.
I've never had platiniums that came out at even 60,000 miles with a decent plug gap. REgardless of material, plug gaps WILL change in 30,000 miles... the extra cost for plugs that "may do" is a waste when new copper plugs out perform them.
Iriidums have a worse problem... smaller electrodes blow out easier. My recent high-compression build was dropping cylinders like crazy with the irridiums and finally idled fine with TR55's. Had to pull those to replace them with TR5's gapped to 0.040" for high rpm stability. Going to Autolite Racing AR103's with a cut back electrode though. This is a LT1 though... YMMV.
Get the copper tops.
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Launching!
Joined: Oct 2007
Posts: 297
Likes: 0
To actually answer your question, iridums are better than platinum. Iridum is a harder metal, so it holds up better than platinum for long service intervals and iridum is a much better electrical conductor than platinum, making for a better spark.
+1 iridium is better. high compression motors will blow out iridium plugs, but your stock...
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go iridium. they don't open up as badly as platinums and they last MUCH longer than copper.
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go iridum.
...
go iridium. they don't open up as badly as platinums and they last MUCH longer than copper.
...
go iridum.
I never had an issue with Denso Iridiums in my 03 cobra, used the IT 22s with 2.80 blower pulley, about 14LBs of boost and no blow out. I had actually tried NGK TR6s before hand and they were fine under WOT, but had a bad miss/tumble at low speed cruising. Currently running NGK TR55s in the Z/28 and couldn't be happier.
On The Tree
Joined: Dec 2001
Posts: 197
Likes: 0
Smaller tips on the iridiums will also be more sensitive to fuel fouling... if you're still tuning, stick with copper.
Going though two sets of Ir plugs in a high compression engine will make you rethink your choice... sure you can gap 'em to 0.030" or less, but why the hell bother? Get a bigger spark and cheaper plugs.
Copper.
Of course changing your plugs more often also gives you more information on how your engine has been running (usually just recently though).
Going though two sets of Ir plugs in a high compression engine will make you rethink your choice... sure you can gap 'em to 0.030" or less, but why the hell bother? Get a bigger spark and cheaper plugs.
Copper.
Of course changing your plugs more often also gives you more information on how your engine has been running (usually just recently though).
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I'm done with Iridum plugs. I put a set in about 30k ago when I pulled them the gap had more than doubled and the car idled like ****. Sorry but if these things don't last longer than 30k why spend the extra money on them. Might as well just us cheap old cooper plugs if they have to get changed that often.
