IK31's and cold starting?
21-10-2009, 06:36 PM
#1
PassionFord Post Whore!!
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IK31's and cold starting?
Will these plugs make a coilpacked cossie harder to start from cold? Ever since fitting them mines been a right pig to get going! Its very hard to start now
Seemed fine on my old NGK9 plugs? Only difference is the IK31's are gapped wider for the coilpack conversion...
Seemed fine on my old NGK9 plugs? Only difference is the IK31's are gapped wider for the coilpack conversion...
22-10-2009, 04:24 PM
#4
20K+ Super Poster.
Really, the point of coilpack is NOTHING to do with larger gaps.
Larger gaps came about with lean burn technology where ever leaner mixtures needed fatter sparks for best performance.
Coilpacks came about due to natural progress, reliability and COST nothing more.
tabetha
Larger gaps came about with lean burn technology where ever leaner mixtures needed fatter sparks for best performance.
Coilpacks came about due to natural progress, reliability and COST nothing more.
tabetha
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22-10-2009, 07:36 PM
#9
22-10-2009, 10:13 PM
#10
It Wasnt Me!
Iridiums just dont seem to last as well as the NGK's, saw many cosworths with a miss-fire use them, swap to NGK's and back to normal...
but if your happy with them then carry on this is just what i've experienced.
22-10-2009, 10:31 PM
#12
the biggest killer of iridium plugs, or any plug imo is incorrectly fitting them,
i see incorrectly fitted plugs every day lol.
if correctly fitted the denso iridium plug is very very good
simple 071cs are also a good cheap option, we use them to over 500 bhp, and they are seriously cheap these days
i see incorrectly fitted plugs every day lol.
if correctly fitted the denso iridium plug is very very good
simple 071cs are also a good cheap option, we use them to over 500 bhp, and they are seriously cheap these days
Last edited by JTECH James; 22-10-2009 at 10:32 PM.
22-10-2009, 11:28 PM
#18
I use IK31's in my car with a group A coil.It did have these fitted when I got it,the only problem I had was a slight misfire in 3rd coming on boost.It only happened the once so I fitted a new set gapped at I think .75.The car gets used everyday and has covered over ten thousand miles on this set without a hicup.It maybe due a new set now though,but there has never been any starting problems.
I have just realised that I am a big fat billy liar,I have ngk bkr9eix gapped at .65 or so my note pad informs me.I have to write everything down because I forget everything.
I have just realised that I am a big fat billy liar,I have ngk bkr9eix gapped at .65 or so my note pad informs me.I have to write everything down because I forget everything.
Last edited by Rax; 23-10-2009 at 01:02 AM. Reason: liar liar pants on fire
23-10-2009, 01:53 AM
#22
The densos can be damaged very easy changing the gap on them
i always check that type of thing before its fitted to the car
He said you dont need to change the gaps just fit and forget
every days a skool day
23-10-2009, 05:26 AM
#23
James is correct. Most Denso Iridiums are damaged by incorrect fitment. They are an excellent plug and will last tens of thousands of miles in correct use. They are also pre-gapped at 0.7mm which is absolutely ideal for wasted spark conversions as luck would have it.
The ONLY negative the Iridiums have is the ultra fine 0.4mm electrode is easily shorted by excess rich mixtures so they arent the best choice for a car that does a lot of cold starts only. IE: One in storage etc...
The ONLY negative the Iridiums have is the ultra fine 0.4mm electrode is easily shorted by excess rich mixtures so they arent the best choice for a car that does a lot of cold starts only. IE: One in storage etc...
23-10-2009, 09:50 AM
#25
First and most common is people levering on the brittle Iridium electrode to gap them. this is BAD and can cause you to lose the end in use.
Second most common is over tightening. You would have to look at a cross sectional view of the Iridium plugs to understand that even slight overtightening can crack the ceramic core insulator. This results in one of two things:
1) The center insulation material breaks away in use.
This can destroy the engine if your unlucky.
2) The cooling efficiency is badly affected, resulting in plug overheating. End result can be detonation or mechanical plug failure.
The plugs have a very specific tightening torque and going past this almost always damages them. If your unsure, have someone else fit them.
Finally, a lot of old school mechanics grease the threads of the plug and this has an effect on the plugs cooling ability. The cooling efficiency is badly affected, resulting in plug overheating.
There are other minor things , but those are the ones we see here every single week. There are way too many people out there who think they know what they are doing but cant even install a set of spark plugs correctly.
Second most common is over tightening. You would have to look at a cross sectional view of the Iridium plugs to understand that even slight overtightening can crack the ceramic core insulator. This results in one of two things:
1) The center insulation material breaks away in use.
This can destroy the engine if your unlucky.
2) The cooling efficiency is badly affected, resulting in plug overheating. End result can be detonation or mechanical plug failure.
The plugs have a very specific tightening torque and going past this almost always damages them. If your unsure, have someone else fit them.
Finally, a lot of old school mechanics grease the threads of the plug and this has an effect on the plugs cooling ability. The cooling efficiency is badly affected, resulting in plug overheating.
There are other minor things , but those are the ones we see here every single week. There are way too many people out there who think they know what they are doing but cant even install a set of spark plugs correctly.
23-10-2009, 05:31 PM
#26
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Interesting reading Stu 
What torque values would you use, do the plugs (never used iridiums) have the settings on the box/destructions ? Or would you use the OE engine torque figures?
What torque values would you use, do the plugs (never used iridiums) have the settings on the box/destructions ? Or would you use the OE engine torque figures?
23-10-2009, 06:22 PM
#27
PassionFord Post Whore!!
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Just to add to this thread, tried my old NGK 9 plugs back in that are gapped to .5mm and the car starts way easier 
I'll try lowering the Denso gap to .7 and see how that goes
I didn't grease the threads of the plug or anything, but i will admit i didn't torque them in, just give them a nip up
Apart from this one issue i'd like to add i feel the wasted spark conversion is worth every penny! Car deffo feels a lot smoother than before, especially coming on boost
I'll try lowering the Denso gap to .7 and see how that goes
I didn't grease the threads of the plug or anything, but i will admit i didn't torque them in, just give them a nip up
Apart from this one issue i'd like to add i feel the wasted spark conversion is worth every penny! Car deffo feels a lot smoother than before, especially coming on boost
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