Another Spark Plug Question

[Galois]

Ok guys, please take it easy on this one, I'm new to all this

I've had a pretty long look through the forums and there seemed to be a lot of dispute when it comes to spark plugs. I've got a stock r34 gtt with cat-back exhaust, what should I be using? I'm not sure what's in there not cos i haven't looked since i bought it (only just read how to), so I'll be having a look this week. There is a miss-fire at idle tho.

So what's the deal? Copper, platinum or iridium? They last different amount of time, right? I'm trying to learn as much as i can at the moment so i don't mind changing the plugs every 5000km with oil (also changing that this week cos, its been almost 7000km and starting to hear a bit of ticking, hoping the change will fix it).

I understand is like this: a certain voltage is sent through the plug, which causes the spark, so smaller gap means the spark happens earlier in the piston cycle (as well as being more consistent as less spark is required). Copper requires less voltage to cause the spark (ie more consistent between cycles?), but due to the properties of copper some of the spark plug is lost during each spark. Platinum and iridium are much harder and thus so they don't erode as quickly. The erosion affects when in the cycle the spark fires because it changes the plug gap.

So, please correct me if this is wrong!! And what do i buy? lol

Thanks in advance

[08yannch]

if ur happy to changing the sparkplugs with oil change then copper plugs are the way to go.

iridium is over kill

and i have found that platinum dont always last 100,000km. i have had some go at 10,000km so im not happy with them but other ppl have reported success.

if u get misfiring at the top end then its because the gap is 2 big or the coils are arcing out. to fix = new coils, close down the gap, silicon the coil mounting bracket.

i have not had misfiring at idle so im not to shore maybe change the oil, sparkplugs and see how that goes.

i personally dont gap my sparkplugs i should to make shore there the same but so far i haven't had any problems other then platinum sparkplugs that shit themselves after 10,000km and some arcing

the part number 4 my copper plugs BKR5E-11

follow this link to understand the part number http://www.ngkspark.com.au/sparkplug.php#

[Galois]

thanks mate. when i posted this i'd only searched the gen maintenance forums, but there's a massive amount of confusing info in the faq sticky in the forced induction performance forums.

hoping it sounds happier after this weeks service, it'll be good to not fear the old oil hurting the engine

[mad082]

don't run the BKR5 plugs on a turbo car. they are too hot and may cause the car to ping, which leads to other bad things. BCPR6ES or BKR6E are the plugs to run. the BCPR6ES plugs are actually a slightly taller plug so will make contact with the coil a bit better, but either will do. those plugs are gapped at 0.8mm, for the ones with the 1.1mm gap (which is stock but may result in a missfire with weak coils) then add -11 to the part number.

as for how often to change them, i pulled my BCPR6ES plugs out after 5000kms and they still looked fine, and were still performing fine even on 14psi, so i could've got another 5000kms out of them easily. the plugs i pulled out before putting the copper plugs in were iridiums that were only 20,000kms and were stuffed, so at 5 or 6 times the price they certainly weren't worth the extra money.

[r33cruiser]

  mad082 said:

don't run the BKR5 plugs on a turbo car. they are too hot and may cause the car to ping, which leads to other bad things. BCPR6ES or BKR6E are the plugs to run. the BCPR6ES plugs are actually a slightly taller plug so will make contact with the coil a bit better, but either will do. those plugs are gapped at 0.8mm, for the ones with the 1.1mm gap (which is stock but may result in a missfire with weak coils) then add -11 to the part number.

as for how often to change them, i pulled my BCPR6ES plugs out after 5000kms and they still looked fine, and were still performing fine even on 14psi, so i could've got another 5000kms out of them easily. the plugs i pulled out before putting the copper plugs in were iridiums that were only 20,000kms and were stuffed, so at 5 or 6 times the price they certainly weren't worth the extra money.

This

For a stockish datsun just chuck in some bcpr6es plugs, clean them, but replace them every 2nd or so service.

At stock boost, I wouldn't be able to justify going iridiums

[mitchum]

Ive always been a fan of the iriduims, they are spendy but they do last considerably longer... cars seems to idle smoother as well...

[Galois]

i see the point of iridiums if they last, the plugs are a bitch to get to, and scary to get to the first time haha

[RusH_]

Another one here for BCPR6ES-11

Go the coppers, and as you said, change them every 5-10k when you do oil changes, they aren't hard to get to and the more you do it the easier it becomes.

[Galois]

i bought bkr6e-11's and went to put them in yesterday, but found 2 of the spark plug cover screws didn't grip the allen key

http://www.skylinesaustralia.com/forums/St...ug-t313301.html