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Spark plug for RB25DET - I know it's been done before ...

benl1981

By benl1981,
in Engines & Forced Induction

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benl1981 Grand Master

benl1981

Posted
Posted

I see there is heaps of threads on it. But what I am looking for is spark pugs for an R33 RB25DET.

I don't really want to spend $17 a spark plug though.

Could I get 25k-30k out of the cheap ones (about $4 each)

I just see there is a bit of plumbing over the top of the engine and the the coils have to come out etc. It's a reasonable job.

Is there any that will give approx 50k or more for around the $10 each mark. I read somewhere that the mid range price ones aren't great i.e. some poeople werehaveing truble with iridiums.

Also gap them down to 0.8mm? I guess if platinum you shouldnt change the gap..

Thanks

Damo Community Regular

Damo

Posted
Posted

You are right, there are heaps of threads on this topic, even for the RB25DET.

One simple rule to remember, the less you pay then shorter time between changing plugs again. Dont expect 25-30000 kms out of $4 coppers. I suggest get the coppers and do the job yourself, its pretty easy with the right tools and change them every 10 - 15000 kms. If u find this task too hard then pay someone to do it and get the platinums or iridiums put in. They will last longer but are more expensive.

Final thought:

U say you dont want to spend $17 on a plug (total of $102) that will last you 50,000kms.

This works out to be .204 cents a kilometer compared to coppers at .24 cents a kilometer.

Money should not be an issue here and i would never put sub standard parts on my R33 just to save a few bucks

Here are a few links. You should be able to make up your own mind after reading them.

http://www.skylinesaustralia.com/forums/sh...k+plugs+rb25det

http://www.skylinesaustralia.com/forums/sh...k+plugs+rb25det

http://www.skylinesaustralia.com/forums/sh...k+plugs+rb25det

http://www.skylinesaustralia.com/forums/sh...k+plugs+rb25det

http://www.skylinesaustralia.com/forums/sh...k+plugs+rb25det

http://www.skylinesaustralia.com/forums/sh...k+plugs+rb25det

http://www.skylinesaustralia.com/forums/sh...k+plugs+rb25det

http://www.skylinesaustralia.com/forums/sh...k+plugs+rb25det

http://www.skylinesaustralia.com/forums/sh...k+plugs+rb25det

Robo's Mentor

Robo's

Posted
Posted

Ive studied plugs a bit, and copper ones wear a little as when copper sparks it burns part of the metal on the plug. Its ok if you want to change them regularly. Iridiums are great but you generally find you have to gap them down, ive gapped mine at 0.8mm.

benl1981 Grand Master

benl1981

Posted
  • Author
Posted

To gap them it only takes about 2mins anyway right. Just put the feeler gauge in and bang them a little on a metal table etc. THat's how I ususallly gap them anyway.

Surely coopers could last say 25-30k? I heard that even platinums you may not get the 100k kms as the plugs may foul quite a bit.

Iridiums the way to go??

You can't gap platinums can you>

Thanks

BHDave Grand Master

BHDave

Posted
Posted
Coppers cant last 25-30k's, they wear away!!!

Iridiums are a better conductor of spark than platnums

Copper's give a better spark initially then start to wear. Within a couple of thousand k's theres nothing in it. iridiums give a more consistant spark for longer.

If you get iridiums you can get 100k on a stock, sedately driven car according to ngk literature.

If you get copper's im sure you could get 30k plus if you baby the car and it is still stock (ngk state 20-40k from memory). Just be prepared for the inevitable miss fires associated with worn sparks at high load/high revs.

For coppers get bkr5es-11 for stock car, bkr6es-11(or -8 if you experience miss firing) for slightly modded car, bkr7es for heavily modded car.

For platinum/iridium equivalent check the ngk aussie website. You can find it on google.

Zahos Mentor

Zahos

Posted
Posted
Copper's give a better spark initially then start to wear. Within a couple of thousand k's theres nothing in it. iridiums give a more consistant spark for longer.

Coppers last a lot more than a couple of thousand km's.

I had my last set for 15,000 km with no issues. My A/F ratios are on a flat 12:1 so it gets hotter than a stock car would.

Only reason they were changed was b/c they were suspected of causing the misfire which turned out to be the coil packs.

I put the old ones back in b/c I cracked a few new ones from over tightening and the car felt no different. (new ones were in for a few hundred km's then removed again b/c they were not gapped properly.)

Iridiums do last much longer, but on a street driven car, they are a waste of money IMHO.

Zahos Mentor

Zahos

Posted
Posted
BCPR7ES - Coppers @ 0.8

Good for Sr20det's too.

that plug is too cold for a daily driver.

As BHDave said, a 5 heat range is good for stock, and 6 for modified.

7 is too cold, and should only be used when heavily modified.

BKR6E, or BCPR6E are your best bet.

They should be gapped at 0.8, and have the V groove which allows more edges for the spark to arc from.

blind_elk Grand Master

blind_elk

Posted
Posted

You can purchase them pre-gapped. Just buy the plugs with the number that ends "-8" ( = 0.8mm gap) - the standard, recommended plug ends in "-11" ( = 1.1mm gap).

You shouldn't need to gap them down anyway. If you find that you do, then you should be looking at the coil packs, not the plugs.

benl1981 Grand Master

benl1981

Posted
  • Author
Posted

Apparenly they don't do the -8 in the iridiums. Would I lose much power if I am running with .8mm instead of 1.1mm if it could actually handle the 1.1mm. I'm going to check my coil packs when I replace the sparkies. Thre is a slight hesitation when boost comes on so I'm thinking either sparkies or coil packs. I don't know how old spark plugs are....

Some say that the cracks are so small you can't even see it?? I was going o do the araldite trick if I can see cracs in them like what some of you guys have done :P

Thanks

BHDave Grand Master

BHDave

Posted
Posted
Coppers last a lot more than a couple of thousand km's.

I had my last set for 15,000 km with no issues. My A/F ratios are on a flat 12:1 so it gets hotter than a stock car would.

Only reason they were changed was b/c they were suspected of causing the misfire which turned out to be the coil packs.

I put the old ones back in b/c I cracked a few new ones from over tightening and the car felt no different. (new ones were in for a few hundred km's then removed again b/c they were not gapped properly.)

Iridiums do last much longer, but on a street driven car, they are a waste of money IMHO.

What i ment by that was the coppers initially provide a better spark then iridiums/platinums. but within a few thousand ks they perform about the same and by 10k or so they are starting to get a bit past it, not that they are completely rooted after a couple of thousand ks

BHDave Grand Master

BHDave

Posted
Posted
Anybody?

Is the BKR6E the platinum, and BCPR6E the copper?

If I get 2 years out of the coppers it should be ok.

both the bkr and bcp are coppers. Both fit though the bcp is the copper equiv for rb20 and 26, the bkr is the copper equiv for rb25.

generally the plugs with IEX (i think) at the end of the part number are iridiums.

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