[Bimmer This]

I was running at the track yesterday and couldn't even get a decent run due to cylinder 5 & cylinder 6 misfires half way down the track. I'm pretty sure that I either have bad spark plugs or a weak coil. What are some performance spark plugs that I can replace the stock ones with or should I just put OEM plugs back in? Thanks

[cstavaru]

From what I read on this forum, no one has found better spark plugs than stock until now...but surely your misfires should be corrected by treating the root cause which you can find at the dealer.

[stimpy]

oem only

[SSSS]

trying out the HKS spark plugs directly shipped from Japan tuners nxt Fri. Appreantly some tuners in JP run the HKS spark plugs and have better result in terms of performance. Well, it is only heard and dyno from the ppl from other side of ocean. will find out myself nxt fri

[Bimmer This]

Please let me know how those HKS one work out. Which plug does the factory run?

[forza1976]

Originally Posted by Bimmer This

Please let me know how those HKS one work out. Which plug does the factory run?

Bosch or NGK homey... They are both about 17 bucks per.

http://www.trademotion.com/partlocat...layCatalogid=0

http://www.trademotion.com/partlocat...layCatalogid=0

[Bimmer This]

I would rather choose NGK over Bosch.

[raceyBMW]

Originally Posted by forza1976

Bosch or NGK homey... They are both about 17 bucks per.

http://www.trademotion.com/partlocat...layCatalogid=0

http://www.trademotion.com/partlocat...layCatalogid=0

Actually can get the stock plugs for less than $10 per
http://www.autohausaz.com/search/pro...2@Spark%20Plug

[Bimmer This]

Originally Posted by raceyBMW

Actually can get the stock plugs for less than $10 per
http://www.autohausaz.com/search/pro...2@Spark%20Plug

Thanks "C". I might have to order those up.

[Former_Boosted_IS]

Originally Posted by TrackRat

Use the OE sparkplugs and be done with it. There is NO performance gain by changing sparkplugs. I have confirmed this on the dyno and track with numerous turbo and N/A engines.

http://www.e90post.com/forums/showth...rkplugs&page=4

This is not accurate at all. This is not about more power on the dyno, this is about a car that has chronic misfires when tuned. The colder plugs may help eliminate that and it is a necessary mod.

[enrita]

yeah , Former you know the missfires i was getting especially on meth? well those missfires cylinder 5-6 were due to the plugs. Just changed them and the missfires are gone...... at the end i was getting them without meth as well and the car was running when cold on 5 cylinders.... gonna try the NGK from the mini cooper 2008 that a couple of people are running now without issues.

[Former_Boosted_IS]

Originally Posted by enrita

yeah , Former you know the missfires i was getting especially on meth? well those missfires cylinder 5-6 were due to the plugs. Just changed them and the missfires are gone...... at the end i was getting them without meth as well and the car was running when cold on 5 cylinders.... gonna try the NGK from the mini cooper 2008 that a couple of people are running now without issues.

Oh, that is great you got it knocked out! PLEASE, PLEASE post your plug results. We must solve this problem.

[enrita]

yep when ALL upgrades are on the car i will open a big thread.

[Bimmer This]

Originally Posted by Former_Boosted_IS

This is not accurate at all. This is not about more power on the dyno, this is about a car that has chronic misfires when tuned. The colder plugs may help eliminate that and it is a necessary mod.

+1. I was pushing 15 psi and kept on getting misfires a little past the 1/8th mile and got limp mode which caused me some pretty good times at the track. I couldn't even get a 100+ trap speed.

Former, I know you are heavily modified. Have you ever changed your plugs to aftermarket colder plugs or run into this similar problem?

Enrita, did you change them out with stock plugs and have not had an issue since?

[Former_Boosted_IS]

Originally Posted by TrackRat

I'm sorry but you are mis-informed on sparkplugs. Colder sparkplugs in no way eliminate misfires and in fact can produce more misfires if the plugs are cold enough to build deposits. Hotter sparkplugs do not misfire... based on engine mods. Colder plugs are not a necessary mod unless you've increased the operating temp of the sparkplug beyond the high-speed glaze and over-heated erosion condition shown in the link below. The photos and captions will help you understand how a sparkplugs heat range inpacts it's performance. Sparkplugs usually misfire based on fuel/deposit fouling, excessive wear/gap, incorrect AFRs, etc. but not because of the operating temp of the sparkplug.

New plugs initially require a lower voltage to fire compared to used plugs. If you had misfires with used plugs and install new OE or other plugs the misfires may go away for awhile but will return if the problem was fuel fouling, deposits, incorrect AFRs, etc.

http://www.google.com/imgres?imgurl=...ed=0CA4Q9QEwAw

While I do appreciate the education, we still need colder plugs for those running heavily modded cars. It would be nice to have them for those of us that are running or will run nitrous. You are obviously educated and know colder plugs will reduce the chance of pre-ignition.

[Former_Boosted_IS]

Originally Posted by TrackRat

Yes but no one has demonstrated any preignition exists on these engines with the OE sparkplugs. Thus you don't need a colder sparkplug, which can actually cause fuel fouling and misfires. No one has even shown high-speed glaze or electrode erosion from excess heat, let alone the signs of preignition. For those who don't know preignition is NOT spark knock, though many people mistakenly think it is. The sparkplug heat range is intended to provide useful sparkplug life.

If you have N54 sparkplugs with high-speed glaze and electrode erosion from overheating please post pics. If you're going to run nitrous then you might need colder plugs but more importantly you will need a different ignition map. You really can't tell about the sparkplug heat range without proper testing.

I think you are working with the understanding of a different platforum. I have run nitrous on pump for a while on my car without a "different ignition map". While I see you are clearly an very educated guy, please understand we are not looking for things indescriminantly. A lot of guys could care less about plug life, but prefer plug performance. The engines generate enormous heat as most DI motors do and in most opinions would have great success with a colder plug. DI motors do quite well defending against knock, but colder plugs under high boost / high heat situations will provide more protection against pre-ignition and that is why we want them.