BKR8 crew, did you notice increased detonation resistance going from 6 to 7 to 8, or are you just going as cold as possible without seeing them foul? Stock is 5 on the 1.8L, going 3 ranges colder still seems really extreme.

 

How much timing are you running at ~220kPa and what gas? I didn't have a chance to tune timing with the 6 range plugs, as they would just misfire above 180-190kPa.

 

CA91, ~10deg advance at 220kpa.

 

100RON, running 19* at 220kPa/7000rpm.

 

Co 91, 10.5:1 static, 15* timing at 7000rpm 220kpa. My 240kpa row drops timing to 12*.

 

CA 91 15* 228kpa 7000rpm
So to be clear, I use bkr7e and not the -11. As far as I can tell the only difference is the gap.
-11's are gapped much larger at .043, while the plain ones without -11 are gapped much smaller at .031.
It makes sense that coils will have a harder time, jumping a bigger gap, under denser conditions.
I bet all you need to do is gap those bkr6e-11's a bit smaller, to say .031-.035.
I didn't notice knock resistance, but I swapped these plugs in when I installed my turbo.

Clearly the d585 coils are capable of jumping a larger gap under more dense conditions.

 

I always re-gap any plugs that go in my car. Can't really compare apples to apples if you're running different gaps on the different plugs.

 

Its not the 8 its the IX. I can also confirm, copper 7s would every so slightly hesitate at 12ish psi, iridium 7s wouldnt.

 

So re-gap 'em to .031 like the eix's & non-11's.
If you still have a problem try the 6eix's.

 

I don't want to gap the plugs down since it hurts idle quality. I'll do a set of 7EIX and pick up a set of 8s to try once I get a chance to get a full-wood tune on the car.

Another piece of the puzzle I forgot about - bought this a while ago and just got it installed. I had ~11psi on the medium can and ~18psi on EBC, but it's only rated to 19 and I was starting to see boost fall off up top as a result. With the Turbosmart dual-port, 14psi springs inside will hopefully let me reach into the mid 20s on EBC without much trouble.

 

Dual port and 4 port solenoid should get you wayyy into the 20s. They say 4+ times the spring.

My goal is 5 psi spring (maybe 3?) And then crank it to 20+ with the 4 port.

 

FWIW, mine was happy doing 3x the spring, but 3.5x got a bit iffy. That was with a dual-port EWG with the 4-port solenoid.

--Ian

 

Interesting. I can do about 3 times on my iwg right now.

 

I want to start with dual-port using the 3-port EFR actuator and see if I can get my desired results before I move to a 4-port.

 

How are you plumbing it with the 3 port? Bottom port to atmo?

 

probably "Two port connection (For controlling boost on a turbo system with high back pressure)" from here. I think that will help the bleed off up top on these. Backpressure can certainly blow these IWGs open. https://system.netsuite.com/core/med...=clear&whence=

 

BKR7EIX [not -11] is an excellent choice, I run them currently in the Miata and I've also run them in the Exige S and my old 318wHP MINI Cooper S. For your power goal, however, you might have to suck it up and run the 8 heat range and deal with fouling. You can't have a big *** cake and eat it too and not have indigestion.

 

If you say so, but the eix's come gapped at .031. Are you going to increase the gap on the eix's to match the gap on the -11's so we know if $10 iridium plugs are actually doing anything?

 

4port EBCS really have no limit in comparison to the spring used, I personally ran roughly a 7lb spring and ran 41psi+ with my 4port ebcs, granted that was with EWG and not a Miata. Theyre golden, but for EWG when modulating boost they have a horrible flutter sound that drove me bananas.

Just my .02

 

It's a daily-driven street car, fouling isn't acceptable. If I were trying to make that 400whp on gas, then yes, but that will be an E85 map and 8s will definitely be too cold for that. Only looking for ~325whp on gas.