Plugs/gap (higher hp)

[beems240sx]

I searched around and found links for people on stock motors and such so no help for me. I have a built sr with 9.0:1 compression. Running 20psi on a precission 5558. I put down 470rwhp/430ftlbs.

Now the car breaks up between 0-5psi

I got new plugs NGK bkr7e, same ones that were in there. What should I gap them too? What other plugs could I try for longevity?

Hopefully this helps other guys searching around too

[beems240sx]

Don't forget to Mind The Gap!

http://i129.photobucket.com/albums/p204/beemsmx6/image-1_zps7ed64312.jpg (http://s129.photobucket.com/user/beemsmx6/media/image-1_zps7ed64312.jpg.html)

KCCO!

[Croustibat]

Unless you are running e85, i'd rather go grade 8 than 7.

Gap rule is simple: run the largest you can run without having the spark blown by the pressure. The more boost, the smaller the gap (or the stronger the coils, your choice).

If it breaks up between 0-5 you have another problem (or a way too small gap, but i mean it ...i am running 0.25" and it is already quite small, if it breaks up under very small boost because of spark plug gap, it means you are running 0.10").

If your coils are in good shape you should be able to run 0.30" .-0.32" .

BTW until you get the car properly mapped, i'd stay with standard copper plugs. The plugs you are using are quite sensitive to being fouled, they are also worth 4 to 5 times more than standard coppers.

[ultimateirving]

Sounds like a bad coil pack or packs. You should not break up in low boost.

[beems240sx]

Sorry totally forgot to mention car is running AEM ems v2. I swapped the plugs and it's a little bit better but still there. Heading to my tuner later this week to check it out

[fliprayzin240sx]

A good rule of thumb is 1 step colder for every 100hp you make over stock. So 205 hp stock, atleast go 2 step colder to 8s, maybe even 9s. Stock are 6s.

[Croustibat]

A good rule of thumb is 1 step colder for every 100hp you make over stock. So 205 hp stock, atleast go 2 step colder to 8s, maybe even 9s. Stock are 6s.

That is just utter bullshit. This is 2013, not 1950 ... do you even know what that grade stands for ?

[Kingtal0n]

cough*

theres some good info about reading plugs from experts in this thread
Plugs, what am i looking at? (http://www.performanceboats.com/dyno/154233-plugs-what-am-i-looking.html)

and about plug temperature and effects on performance.

[mmmS13]

That is just utter bullshit. This is 2013, not 1950 ... do you even know what that grade stands for ?



Its actually 100% a good rule to go by... are you sure you know what you are talking about?

[Kingtal0n]

Its actually 100% a good rule to go by... are you sure you know what you are talking about?

yeah crusti are you sure? :trogdor:


rule #1
Plug gap should be as large as you can get away with.

[fliprayzin240sx]

That is just utter bullshit. This is 2013, not 1950 ... do you even know what that grade stands for ?

Yup, its bullshit cuz my 500hp SR was running NGK Iridium 9s gapped to .028 for 3 years and strapping was good. :rolleyes:

[Kingtal0n]

I personally like a big old .045" gap on mine. Use an MSD box np.

[mmmS13]

yeah crusti are you sure? :trogdor:


rule #1
Plug gap should be as large as you can get away with.

Yes because I actually had problems using 1 step colder plugs when I made 200hp over stock.. went 2 steps colder and wha-lah! Car runs perfect.

[Croustibat]

Its actually 100% a good rule to go by... are you sure you know what you are talking about?

Grade 7 plugs are too cold for my 300+ HP CA18DET, so yes i am quite sure. It should be running grade 8s based on your ideas.

Grade 8 plugs are nearly too cold too on a 500+ HP CA18DET i know. It should be running grade 9s based on your ideas.

So yes, i am pretty sure the +100HP = +1 grade is bull.

As i said, this is not 1950 anymore, we run various fuels and dont use carbs and centrifugal timing distributors ... big flawed old V8s needed that kind of rule, yes. We dont run that in our cars, so it does not apply.

[Croustibat]

Yup, its bullshit cuz my 500hp SR was running NGK Iridium 9s gapped to .028 for 3 years and strapping was good. :rolleyes:

It worked, does not mean it is good.

Believe what you want anyway, but please dont spread "knowledge" you dont even understand :duh:

[reeskm]

Rule #2: If running more power than stock, increase the heat of the plug as needed to avoid detonation and pre-ignition.

Every motor is different. More heat is produced with more torque output, not HP output.
https://en.wikipedia.org/wiki/Spark_plug#Heat_range

[Croustibat]

Rule #2: If running more power than stock, increase the heat of the plug as needed to avoid detonation and pre-ignition.


That is exactly what i am saying. no det nor pre-ignition, no plugs melting ? No colder plugs. Dont just put colder plugs because people told you to do it on the internet. Check you NEED it first.


Every motor is different. More heat is produced with more torque output, not HP output.
https://en.wikipedia.org/wiki/Spark_plug#Heat_range

Actually HP is torque x rpm, so call it torque or HP it does not matter.

Also torque has a direct relationship with displacement; 2L NA engines usually have around 180Nm of torque, +/-10 , whichever way they are built. Boost it to 1bar and it produces twice more,all other things being equal (which they never are so it always produces less).

[mmmS13]

Grade 7 plugs are too cold for my 300+ HP CA18DET, so yes i am quite sure. It should be running grade 8s based on your ideas.

Grade 8 plugs are nearly too cold too on a 500+ HP CA18DET i know. It should be running grade 9s based on your ideas.

So yes, i am pretty sure the +100HP = +1 grade is bull.

As i said, this is not 1950 anymore, we run various fuels and dont use carbs and centrifugal timing distributors ... big flawed old V8s needed that kind of rule, yes. We dont run that in our cars, so it does not apply.


But grade 7s are perfect for my KA. Okay makes sense, I don't know why I post on Zilvia (even though I barely have) I don't try and swing my E-dick around :hey:

[Croustibat]

Dude, why dont you tell people how you decided the plugs you selected where good ? Except "i had problems and then i didnt have", which is not exactly what could be described as a scientific method.

how about some pics of your plugs, and your tuning setup ?

How about trying to solve the reason you had problems with 1 grade colder before going 2 grades ? Oh wait i know. 2 grades colder magically fixed your problems, so no need to investigate after all, it could absolutely not have been a side effect :rimshot:

Anyway as i already said, you may be right, it worked FOR YOU. Which does not mean it would work with every engine setup. Seeing how a KA is built and how an SR is built, i would not be very surprised to see the old crappy V8 rule of thumb apply on it and not on an SR.

Because -yes- we are talking about an SR here, not about a converted truck engine only american people got.

[reeskm]

Actually HP is torque x rpm, so call it torque or HP it does not matter.

Also torque has a direct relationship with displacement; 2L NA engines usually have around 180Nm of torque, +/-10 , whichever way they are built. Boost it to 1bar and it produces twice more,all other things being equal (which they never are so it always produces less).

N/A or Turbo, when your motor is at it's torque peak it will be working it's hardest. This is where peak combustion temperatures occur.

See the wikipedia article I linked:
"However, the level of torque currently being produced by the engine will strongly influence spark plug operating temperature because the maximum temperature and pressure occurs when the engine is operating near peak torque output "

Although you are correct about your formula, the ECU will make a big difference to how much temperature the car makes at different RPM. My buddy's miata dosen't even use a knock sensor from the factory! That means the ECU is more primitive and compared to a more modern N/A miata could have a totally different combustion temperature profile.

A car with problems in the ECU and sensor circuit will run poorly and also change the spark plug requirements.

So it all depends! LOL

[mmmS13]

Dude, why dont you tell people how you decided the plugs you selected where good ? Except "i had problems and then i didnt have", which is not exactly what could be described as a scientific method.

how about some pics of your plugs, and your tuning setup ?

How about trying to solve the reason you had problems with 1 grade colder before going 2 grades ? Oh wait i know. 2 grades colder magically fixed your problems, so no need to investigate after all, it could absolutely not have been a side effect :rimshot:

Anyway as i already said, you may be right, it worked FOR YOU. Which does not mean it would work with every engine setup. Seeing how a KA is built and how an SR is built, i would not be very surprised to see the old crappy V8 rule of thumb apply on it and not on an SR.

Because -yes- we are talking about an SR here, not about a converted truck engine only american people got.

I guess I should have mentioned I tried the 1 step colder plugs re-gapped still didn't work, I suppose common sense would've dictated I tried that before going a step colder but I guess you've have too much wine and cheese over there :D Also, theres no point to going in the trash 9 months back to find some fouled plugs + my tune is in my bio but theres no point to continue. If I get deployed to France I'll come look you up and we can continue a dumb debate that isn't helping the op.

[TheRealSy90]

Okay, here's what you do.

Get some oem sr plugs, gapped to oem spec.

Install GM LS Truck coilpacks.

Problem solved, end thread.

[So Make Like]

I guess I should have mentioned I tried the 1 step colder plugs re-gapped still didn't work, I suppose common sense would've dictated I tried that before going a step colder but I guess you've have too much wine and cheese over there :D Also, theres no point to going in the trash 9 months back to find some fouled plugs + my tune is in my bio but theres no point to continue. If I get deployed to France I'll come look you up and we can continue a dumb debate that isn't helping the op.

You have 9 months worth of trash in your possession? Ho nah.

[Kingtal0n]

Actually the formula is

horsepower = [Torque X rpm / (33,000 / (2PI))]

Technically speaking, your highest cylinder pressure is going to be peak torque. That holds true most of the time- however, if your ignition timing is not correct, there may be instances at lower torque outputs where the cylinder pressure will spike higher than it (ever) should, and that can pop a head gasket. If you are lucky.

[steve shadows]

.028 standard always did me well whatever the setup...

[Croustibat]

Anyway the OP has a problem, and it does not come from spark plug gap nor grade, that is for sure...