Spark PLugs

[DREMEN]

I just got back from another dyno run (179kw @ wheels) :D

But I have a miss :(

The tuner believes it is the spark plugs....

Which ones should I use?

He said something about 5 or 6.

What should they be gapped to?

Thanks for your time

[DREMEN]

Here is the graph

[DREMEN]

Sorry something went wrong... I am still new to this forum..

[Guest Master of Disaster]

dude the power curve looks a bit too much like a roller coaster, did the dyno operator back off the throttle at about 115kms??!

You should be able to iron out all those dips! Doesnt look very linear! How does it drive?

I dunno about the heat ranges, but im using Iridiums, gapped to 0.8, which seems to be accepted as the ideal gap. (from a test done in a mag). My old plugs started missing heaps, i pulled them out and the gap was 1.1, which didnt work at all. 0.8 saw the return of smooth clean power.

Cheers, MASTER

[walkoau]

i use platinums 0.8 and never missed beat.

when ever you buy a set of plugs for ur car they should be pre-gapped to 1.1 but always regap them most ppl regap theres to 0.8mm

[DREMEN]

Originally posted by Master of Disaster

dude the power curve looks a bit too much like a roller coaster, did the dyno operator back off the throttle at about 115kms??!

You should be able to iron out all those dips!  Doesnt look very linear!  How does it drive?

I dunno about the heat ranges, but im using Iridiums, gapped to 0.8, which seems to be accepted as the ideal gap. (from a test done in a mag).  My old plugs started missing heaps, i pulled them out and the gap was 1.1, which didnt work at all.  0.8 saw the return of smooth clean power.

Cheers, MASTER

That up and down is the "miss" hopefully just due to the spark plugs.... it seems to drive fine on the road....

I haven't replaced the spark plugs since I got the car from japan and therefore they haven't been regapped to run higher boost...

That is why the curve looks like a coke bottle

Where do I buy good plugs from? I.e HKS or Iridiums?

[sileighty]

NGK offer some pretty good spark plugs. how old are the plugs, you might just have to give them a clean.

[DREMEN]

Originally posted by sileighty

NGK offer some pretty good spark plugs. how old are the plugs, you might just have to give them a clean.

They were in the car when it came over from japan so no idea...

[sileighty]

could have a look on the net for some good sights that sell quality spark plugs. or go down to repco, autobarn, ect. tell what you got and shouldnt be a problem.

i am up for a change in timing belt and plugs and stuff. going to try some ones from ngk i think with 4 contacts. see how i go

[Zahos]

Iridiums and platinums do not offer any better spark over copper. In fact, the copper plugs are better conductors and offer a better spark. Only think is they dont last as long, which is a good thing on a tuned high performance car, as you would want new plugs at least every 20,000Km.

The Iridiums and platinums till have a copper core anyhow, but have a thin layer coating the core. They shouldn't be re-gapped b/c their tips can be easily scratched, thus turning them into $20 copper plugs as oppossed to $3 copper plugs.

Try some NGK copper plugs, they will work just as well, if not better for a fraction of the price.

The plug you need depends on your driving habbits....

If you drive like a grandma most of the time, NGK BCPR5E or (BCRP5E-11)

If you take it on the track, or thrash it quite often, go for the same in a 6 heat range, so BCPR6E (-11)

Whatever you end up getting, regap them to 0.7. Then make sure you tuner advances your timing to past the 20degree mark (as long as their is no knocking, if there is then he should retard the timing to a safe level). This should help make that power curve look a little more linear. You will never fully get rid of the problem unless you get aftermarket management, as it is an issue with your ignition timing curve on the stock ECU. Boost + stock ECU + VCT = miss at 5000 rpm!

Zahos

[adam 32]

i run champions of heat range 7 and gapped to 0.7mm

the part number for NGK is

BCPR7ES and gap them to 0.8-0.7mm

basically the more boost u run the closer u should gap the spark plugs

[Zahos]

for a larger turbo, a heat range of 7 is good, but for the satandard turbo, 5 is good, or 6 if u are around the 180kw mark. Anything less on an R33 with standard turbo, and you will definately see problems at the 5000rpm mark.

I had 7's in mine with 12psi boost, and for the 1st 2 weeks it was fine. After that they soon fouled easily, so I went down to 6. Because I drive it to work, and dont often thrash it, they fouled after a while too. I've had 5's in there for 3 months now, and I have had no issues...

In DREMEN's case I wouldn't go past a heat range of 6...

[DREMEN]

Thanks everyone for the info I'll let you know how I go

[dru32]

my r32 seems to be missfiring aswell, I dont even know where to find the spark plugs... How do ya clean them?.. Would i need new ones? My car is stock.

[ron]

hi

dru32 check out www.ngk.com.au and you should find all the info you need to check a used spark plugs.

i just put in NGK iridium heat range6 in on the weekend and the car runs great. they r only around 20 bucks and already gapped at .9

ron