R34 Rb25Det Neo Spark Plugs

[Shoujiki]

Hey guys,

I know this is beating a dead horse but I've been looking for some definitive information on which plugs to use on my engine.

There's allot of people using different heat ranges, Iridium, etc but i'd just like some good solid "this is what you should use".

Now i haven't checked whats in there at the moment (however whatever is in there, may not be perfect so i thought i'd ask).

The motor has a FMIC, Splitfire Coil Packs and is running a controller between 8 (lo) and 10 (hi) psi.

From reading, the "BCPR7ES – 8 or 11" seems to be what people say to use with the Split Fires (since it states to use one colder heat range?)

Do I use a -8 or -11 gaping?

And i'd assume Iridium are a waste of time, since it's not that hard to to get to the plugs to change standard coppers ones?

Thanks guys.

[GTSBoy]

The reason to use coppers over iridiums has more to do with a lot of people having trouble with the iridiums.

At 8 - 10 psi boost with the standard turbo you should have no reason to gap your plugs down to 0.8mm, especially seeing as you have some nice strong coils in there. So buy or leave the plugs gapped at 1.1mm. The wider the plug gap the better, unless it is misbehaving (missing, breaking down at high boost, etc), in which case then you gap them down. But the same rule applies - the bigger the gap the better, so don't automatically gap anything down to 0.8 before trying 1.0, then 0.9.

[Shoujiki]

Gotcha, thanks mate. Bigger gap = more spark = better yield for a burn. Makes sense.

So the one step colder heat range is correct for using Splitfire coil packs?

[GTSBoy]

So the one step colder heat range is correct for using Splitfire coil packs?

I wouldn't know about that being a general rule. Again, because yours is pretty much standard, you're not likely to notice much difference from changing plug heat range anyway. When I put Splitfires in my RB20 I didn't change the plugs, and it has just continued to run fine (well, it actually runs better than with the old coils both because the old ones had shit themselves so it really wouldn't run for long at all at the end...but also the Splitfires are just stronger than the old coils were when they were nearly but not quite dead and so you'd bloody well want it to run a bit better!).

I think if you're leaning on an engine (big turbo and boost) and have been using weak old coils and gave been running plugs one or two ranges hotter than normal to help, then you probably don't need to keep running the hot plugs after fixing the coil problem, more so than saying you can use a colder heat range plug just because you're changing to Splitfires.

cheers

[JonnoHR31]

BCPR6ES-11 if your coils are good (sounds like it). if it misses gap them down .1mm at a time until it stops. 7s are pointless in a stock motor and will only foul up slightly faster for no gain.

[dori34]

for your boost level & power, the BCPR6ES-11 is what you need.

there is no such thing as BCPR6ES-8, there will only be BCPR6ES (which is .8mm gap)

.8mm gap is used for when running higher boost (12psi+)

[kitto]

Oh dear, another spark plug thread lol.

As above, i'd have to say the BCPR6ES gapped to .9 - 1.1mm. You wont know exactly what gap will work for you, but i would think with only 10psi boost and split fires, you should be able to use them at 1.1mm with no problems.

Fairly stock motor, so keep the 6 heat range plug.

Ideally you'd use Iridiums, as they last a long long time. By i, myself are one of those people that have had nothing but issues with them.

[Simon-S14]

i use the 6 heat range running 300 +rwkw and e85

[Shoujiki]

Perfect guys, thanks tons for the info! Clears everything up! Sorry if it's been talked to death! Just sometimes hard to find definitive information without people talking about other things

Thanks again!

[Shoujiki]

Ok installed the BCPR6E-11's into the motor the other day. The motor had the BCPR6E's in it, so .8 gap. Car seems to run good with the 1.1mm gap and Splitfire coils. No idea if it's just placebo though haha. The plugs that came out were pretty good still.

A tuner told me yesterday that I should not be using the BCPR6E-11's because 1) the gap is too big, 2) the heat range is too hot for the current Summer climate and 3) They are a "crap plug". He recommended BKR7E's, and gapping them down to 0.7mm-0.8mm, does that sound correct? He said using 1.1mm gap will cause the spark to "blow out" at my boost setting (10 psi).

Confusing!

[GTSBoy]

Bullshit. He should be kicked in the nuts.

[JonnoHR31]

^this, your tuner sounds like a muppet. you want to run the biggest gap you can without getting any spark blow out, so if its not missing under load 1.1 is fine, most standard cars with old coilpacks will blow out at 1.1 with higher than standard boost, but that doesnt mean you should run a smaller gap on all cars regardless of condition.

6's are fine, they're still 1 heat range colder than standard, 7's will simply not last as long for no gain whatsoever in your case.

the only difference between the bcp and bk is the v groove tip and depth, fairly minor differences and both will work fine.

[Shoujiki]

Thanks mate. good info

[silviaz]

On 1/4/2012 at 12:13 PM, GTSBoy said:

The reason to use coppers over iridiums has more to do with a lot of people having trouble with the iridiums.

At 8 - 10 psi boost with the standard turbo you should have no reason to gap your plugs down to 0.8mm, especially seeing as you have some nice strong coils in there. So buy or leave the plugs gapped at 1.1mm. The wider the plug gap the better, unless it is misbehaving (missing, breaking down at high boost, etc), in which case then you gap them down. But the same rule applies - the bigger the gap the better, so don't automatically gap anything down to 0.8 before trying 1.0, then 0.9.

The BCPR6ES come gapped at 0.9mm, and I have spitfires and is lightly modified. I assume there's no need to modify that gap as per what you wrote above? Mine's also maxes out at 10 psi.

[GTSBoy]

Well, splitfires are no different to a new stock coil, and stock boost is ~ 10 psi.....so 1.1mm is the likely best plug gap. Go ahead and use 0.9mm. It's not going to change the world.

[silviaz]

9 hours ago, GTSBoy said:

Well, splitfires are no different to a new stock coil, and stock boost is ~ 10 psi.....so 1.1mm is the likely best plug gap. Go ahead and use 0.9mm. It's not going to change the world.

I thought r34 gtt's run stock boost 5-7 psi?

[GTSBoy]

7 is stock. Put an exhaust on it, easily see 8 or 9. Put a bigger intercooler on it, easily see 10.