I am going to start building my motor and I need to know what spark plugs are best? I have a fully built 6 bolt with FP Green 850cc injectors 255 walbro and I am going to use coil onplugs.
Thanks,
J
Thanks,
J
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rheckert
Well-known member
ngk bp7es correctly gapped imho
Dialcaliper
Well-known member
+1 NGK
Either the BPR7ES, or the BPR7EIX Iridum if you feel like spending the extra money.
Also, the R (resistor plug) is important - our cars have electronic ignition and fuel injection (it doesn't matter for distributor/carburetor engines)
Either the BPR7ES, or the BPR7EIX Iridum if you feel like spending the extra money.
Also, the R (resistor plug) is important - our cars have electronic ignition and fuel injection (it doesn't matter for distributor/carburetor engines)
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rheckert
Well-known member
Thank you for the correction. I get the cheaper plugs and change them more often.
Nobody indexes spark plugs anymore?
BadVr4
Well-known member
iridium is no good for boosted cars
gvr4ever
Well-known member
I couldn't find the information, but I thought Extreme Motersports did a test on spark plugs. The cheap copper ones were the best for just about every boost application. This has been well known for some time.
I think the iridium plugs were better for very high boost applications tho. Copper plugs are probably the right choice for 95% of us. That's what I run.
I think the iridium plugs were better for very high boost applications tho. Copper plugs are probably the right choice for 95% of us. That's what I run.
Hertz
Staff member
What is different with the resistor plugs?
They have an "R" in the number. /ubbthreads/images//graemlins/wink.gif
Myles
Well-known member
And I'm pretty sure they're gapped out of the box at .40. So you have to make sure to properly gap them. As with any plug but definitely always check the R's
Dialcaliper
Well-known member
They have a resistor in them. /ubbthreads/images//graemlins/rofl.gif
Quote:
What is different with the resistor plugs?
Whenever you have a high voltage spark gap going off, it causes radio frequency interference, which can cause problems with electronics, especially engine control computers, sensors, and the ignition system itself. Varies from vehicle to vehicle, but in general the resistor, along with good plug wires, will help reduce the RF generated to an acceptable level. That, and the ignition system is designed to use it (sort of like high and low impedance fuel injectors - use the right kind)
Teh interweb knows all
Quote:
What is different with the resistor plugs?
Whenever you have a high voltage spark gap going off, it causes radio frequency interference, which can cause problems with electronics, especially engine control computers, sensors, and the ignition system itself. Varies from vehicle to vehicle, but in general the resistor, along with good plug wires, will help reduce the RF generated to an acceptable level. That, and the ignition system is designed to use it (sort of like high and low impedance fuel injectors - use the right kind)
Teh interweb knows all
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GVR-4
Well-known member
acustark
Well-known member
Has anyone looked into the new Pulstar Plugs? They use a new technology to increase the spark, but add a caution to only use them with a stock setup. They do have another option for modified cars, but it sits atop the plug and would be a fit problem for our cars. I had planned on going to the COP, but if these work I may direct my $$$ elsewhere.
Dialcaliper
Well-known member
Hrm - looks like snakeoil to me. Their diagram is basically showing a secondary coil that would "store" energy normally used up by heating the plug and components. The problem is that all of the same components are seeing current regardless of the plug used, and "When the ignition power overcomes the resistance in the spark gap, the pulse circuit discharges all of its accumulated power" is true for any spark plug. They are somehow claiming that their plug doesn't require current to be used for ionization before the spark can jump the gap, which is also BS
Once ignited, the flamefront speed is determined by cylinder pressure. I don't buy the "increased cylinder pressure" bit. I certainly don't buy the claimed performance gains unless the original plugs on the vehicle are in awful shape. If anything, the circuit in there would retard the ignition timing, which would make things worse. Also, their pretty graphs are completely nonsensical - "Normalised Ensemble Velocity"? They can't even spell!
The only point they do have is that your typical ignition timing is pretty variable, and a given cylinder can preignite or misfire quite often.
Spark plugs for $25 each?
They also pulled the same cheater trick that every other "mpg/pwr/trq enhancer" does of running the car normally first (a total of 30 miles "city", 60 miles "highway") and then swapping the plugs. The first part of the test, the car isn't even warmed up, and they're taking mpg data based on less than a tank of gas.
Lastly, their two "in the news" entries are a blurb in a skeezy magazine, and advertisement in popular science
I call shenanigans.
Once ignited, the flamefront speed is determined by cylinder pressure. I don't buy the "increased cylinder pressure" bit. I certainly don't buy the claimed performance gains unless the original plugs on the vehicle are in awful shape. If anything, the circuit in there would retard the ignition timing, which would make things worse. Also, their pretty graphs are completely nonsensical - "Normalised Ensemble Velocity"? They can't even spell!
The only point they do have is that your typical ignition timing is pretty variable, and a given cylinder can preignite or misfire quite often.
Spark plugs for $25 each?
They also pulled the same cheater trick that every other "mpg/pwr/trq enhancer" does of running the car normally first (a total of 30 miles "city", 60 miles "highway") and then swapping the plugs. The first part of the test, the car isn't even warmed up, and they're taking mpg data based on less than a tank of gas.
Lastly, their two "in the news" entries are a blurb in a skeezy magazine, and advertisement in popular science
I call shenanigans.
grocery_getter
Well-known member
I've abandoned the "P" and now running just the straight BR*ES series.
Quote:
Nobody indexes spark plugs anymore?
What for ? /ubbthreads/images/graemlins/wink.gif
The real reason for Indexing plugs is 1: to project the strap away from the piston dome or 2: to advance or retard the timing on one particular cylinder based on EGT's or Pressure sensors.
/ubbthreads/images/graemlins/cool.gif
Nobody indexes spark plugs anymore?
What for ? /ubbthreads/images/graemlins/wink.gif
The real reason for Indexing plugs is 1: to project the strap away from the piston dome or 2: to advance or retard the timing on one particular cylinder based on EGT's or Pressure sensors.
/ubbthreads/images/graemlins/cool.gif
