Irridium Spark Plugs

[joseph]

I have a question about irridium spark plugs. Are a good choice use in my dsm or not and why?

 

[90GSX]

No.

Use NGK BPR6ES if you're stock to mildly modded, NGK BPR7ES if you're mildly to heavily modded. Gap them to .028"

 

[joseph]

are those platinum or irridium, and why did you say those?

 

[90GSX]

They are regular spark plugs, no fancy space aged, composite irridium carbon denso platinum, just plain cheap OEM plugs. You can buy them at most any auto parts store, though you may have to specal order the 7's. NGK's are probably the most commonly used plugs in DSM's.
http://www.dsm-performance.com/catalog/plugs.php?DSMid=f5aca3ce316e03407bc1caa70f106469

 

[joseph]

thanks for the help!

 

[90GSX]

No problem, good luck.

 

[doug]

I've been using the NGK Iridium spark plugs for about 8 months now with no problems. Not saying the standard ones aren't as good, but everyone seems to slam the Iridiums (I only got them because I got a good deal on them). It's my based-on-nothing-whatsoever opinion that many people just lump them in with platinums and say "Stay away" without having good reasons. I know why platinums are not recommended, but I didn't think the same things applied to the iridiums.

So what are some things to watch out for with the Iridiums? Has anybody actually had problems with these first-hand? 90GSX, I've read many of your posts and you seem to know tons about these cars (lots more than me), so I was just wondering if you could expand on this a little...

 

[KenTSIII]

Ever pull he iridiums out & check the gap? I too figured they got thrown in w/ the platinum BS. Ever try throwing some 6es plugs in there & seeing if there was any difference? Most people recomend the NGK 6/7es due to the fact they work REALLY well.. & they are normally pretty cheap & readily available. Platinums completely suck.. they don't make a large enough spark & the electrode wears really fast. Never heard anything good about the iridiums... also who could justify $9 a each for spark plugs?

 

[HondaEatingTSi]

What do you guys think of the BPR8ES spark plug. I have been told by a few people to run these in my car. I have the 7es's in right now. I would list my mods but it would take to long. In short I have a custom 16 that runs 575 cfm @1 bar. Set to 24 psi. wally255, safc, 660's. and a 2 g mas. ran a 12.7 @17psi on pump gas. But i want to go faster.

 

[doug]

Originally posted by KenTSIII
Ever pull he iridiums out & check the gap? I too figured they got thrown in w/ the platinum BS. Ever try throwing some 6es plugs in there & seeing if there was any difference?

I've pulled them before, but didn't check the gap-- just did a visual inspection. I'll check the gap on them since I've had them in there a while now. And yeah, I may throw some regular BPR6ES ones in there just to see if it makes a difference. Thanks.

 

[90GSX]

Originally posted by doug
I know why platinums are not recommended, but I didn't think the same things applied to the iridiums.

So what are some things to watch out for with the Iridiums? Has anybody actually had problems with these first-hand? 90GSX, I've read many of your posts and you seem to know tons about these cars (lots more than me), so I was just wondering if you could expand on this a little...

Personally, I can't justify spending $40 on a set of plugs when an $8 set of plugs work great. I'll put the other $32 in my "goTTa HaVE AlteZZas" fund.

 

[doug]

Originally posted by 90GSX
I'll put the other $32 in my "goTTa HaVE AlteZZas" fund.

:laugh:

Yeah, I only got 'em because they were a good deal at the time. More than the regular ones, but not $40 for the set-- I think it was around $20 for the set. Anyway, I'll keep an eye on them and maybe just swap some regular ones back in to compare. Thanks for the info.

 

[GSX4LIFE]

I had the Irridiums in my car for about a year. One bottle of Nitrous was easily enough to destroy them. After one year teh gaps were opened up to about .042" on all 4. I now use 7s. In other words, they are not worth it.

 

[Spinall4]

I've been running the Denso iridums for less than a month, but they make my car Idle better. I just thougth I would give them a try and they haven't let me down so far. Every one talks about how much cheaper normal NGK's are, but normal NGK's only lasted me about 10k mi, I'm expecting the irdiums to go twice that, and hoping they will go 3 times that, in wich case you have to factor in the cost of 2 or 3 sets of ngk's.

 

[KenTSIII]

Even if they last 3 times as long as the normal NGKs (I doubt they will) then that still doesn't make up for the fact that they cost 4-5 times as much.

 

[ModInProgress]

Listen to this.. we put bosch platiniums in my friends 90 dsm and it was lagging alot and idleing rouhg .. it turns out that the far right cylinder had a spark plug with a cracked electrode and a gap of about .1... now that cant be good.. and cat allow spark. hahaha now we put ngks and its a world of difference althogh it was not slow before we changed them it still beat mustangs.

 

[spyderman]

Understand that the whole purpose behind Iridium plugs is the fact that the melting point of Iridium is far higher that Platinum which allows for an electrode to be extremly small. This actually concentrates spark energy which in turn creates a hotter spark. In a properly tuned and monitored engine (not to lean) the plugs should last 50k or better. I did the math and they were worth the extra investment to me. But that's just me.

:xnuts:

 

[HPF_MK3T]

Well, the benefit of Platinum and Iridium are that they are a harder metal so they last quite a bit longer than Copper, some last up to 100k miles, but average is 3 times that of a standard copper. Another benefit is that they require a lower operating voltage, ie less coil charge time to reach the plugs ionization point, or the voltage required to jump the gap. Most ignition systems that use a distributor-type igntion system will benefit from these plugs because they have 1 coil that fires every plug, which leaves the coil with less charge time, unlike a distributorless or DIS system that has 1 coil per plug, or 1 coil per 2 plugs. A Majority of DIS ignitions systems come with Platinums factory, Autolite for Ford, AC for GM, Champion for Mopar, NGK or Denso for Imports. Most platinums on these applications will work up to about 25psi on boosted applications with a reduced gap. On High boost applications I've seen much less high boost spark blow out using the Denso iridiums, the NGK Irid's don't seem to be as good of quality. But again, different cars and modifications may change how the car accepts different plugs.

Heat Range is how quckly the spark plug transfers heat away from the center electrode into the cylinder head. Colder plugs cool down faster, hotter plugs cool down slower. Say a standard plug runs fine when cruising/idling, but under full throttle you're generating too much heat that's causing pre-ignition or detonation because the cylinder temps are gettng too high. You may benefit from going to a colder plug, but when it comes to idling/cruising, the plug may not be able to stay hot enough to burn off the fuel and you may have problems with the engine loading up due to unburnt fuel. The only thing you can create a "hotter spark" with is an ignition upgrade, such as an Ignition amplifier or capacitive discharge box. A tune up with performance wires and new cap and rotor will usually produce a mildly hotter spark due to less resistance in the ignition path. I hope this information helps.