What kind of plugs are you running? Heat range?

[Martin S.]

I've heard NGK plugs are best more than once. I'd like to order some plugs and was wondering what others are using. My turbo has had NGK DPR9EA in it over the last few years.
For my other, more stock engines, AC Net recommends this plug and I am wondering what you think about it... http://vwparts.aircooled.net/NGK-BP5HS-Spark-Plug-14-x-1-2-Reach-Threads-p/ng4111.htm

[modnrod]

Most of my "stock" engines still have a decent exhaust, close deck, pocket-ports with good seats and usually 8:1 comp, so in mine I run NGK B6HS or Denso W20FSR.
I only use "5" or "16" heat range plugs in completely stock low-comp engines, and even then in our summer I sometimes swap to the slightly cooler "6" or "20"s for highway running.

[Martin S.]

I see. So the higher compression, closer to stock type engines should be running the colder plug. What do you think of the projected tip plugs? Your plug is the regular tip, but John thinks the projected tip is much better. My turbo has the projected tip plugs in it.

[modnrod]

Projected tip just puts it further into the chamber I guess.
It might make for an easier burn, might not, that man knows his stuff though.
If I've ever had misfire issues I tend to just close the gap a bit.
If you run the colder plugs in your town and they get a bit black when it's cold weather (which I don't get here) then go back to "5"s if you need to of course.

[Martin S.]

That makes sense. The turbo also has Electromotive direct fire ignition which has more power and can jump the larger gap on those plugs.
Here's a pic of plugs from my more stock 1776, although it is high compression compared to stock.
A regular German bosch is on the right, and an NGK B7HS that the builder had installed. I did notice the bosch looked like they were running hot compared to the 7's.
Also the bosch has more of a projected tip than the B7HS.

[Martin S.]

I put an order into ClubPlug.ca which is a great site for cheap NGK plugs in packs of 10. Only $3 per plug (CAD$) and free shipping, nice. For the 1776 I got BPR7HS which is the projected tip resistor version in a cold version for the 9.4:1 engine (and maybe for my stock engined 71 Bus). Also got DPR9EA-9 which are the same as what Steve originally installed in my turbo.
Reading NGK info I didn't realize that it is the job of the spark plug to help cool the combustion chamber. From their info:

The spark plug has two primary functions:
  To ignite the air/fuel mixture
  To remove heat from the combustion chamber

There is some good reading here: http://www.ngksparkplugs.ca/tech-info-spark-plugs.cfm

[alex d]

Is there a reason for using the resistor versions?

[Martin S.]

For the turbo, I went with what was installed which was the resistor plug. That's what the builder put in, so it makes sense to replace it with the same. I doubt that the static would affect the ECU, but my cars are all daily drivers with radios so I don't want to hear static.
Also, when I did a search on the ClubPlug site, there was no availability of the BP7HS but when I added the R, those ones were available. From what I understand, there is no reason not to use a resistor plug and cables too. I like the look of the NGK wire set for bugs on the site (RC-VWC032) and the price is very cheap comparable to the cheapest no-name wires that are pure crap.

[Dougy Dee]

I called NGK Canada customer service late in April about non-resistor plugs.
I was told NGK no longer make non-resistor plugs!
After having a set of NGK 'R' plugs misfire with sparking shooting out between the porcelain and metal.... No thank you.
The new Bosch don't play nicely with our points and Blue coil ignitions...
Time to look at Denso or

[Martin S.]

From the Electromotive installation guide for my system,

about resistor wires:

"Spark Plug Wire Selection
The XDI outputs an extremely high-energy charge for the ignition coils. Resistor (carbon) core wires work best with this charging method, since they absorb electrical noise generated by the coil firing events. Use 8mm or larger RFI and EMI suppression wire with GM boots. We recommend using a carbon core-style suppression wire with a resistance of 3,000 to 5,000 ohms per foot. SOLID CORE WIRES SHOULD NEVER BE USED."

and about resistor plugs:

"Spark Plug Selection
Use of resistor plugs is highly recommended for optimum noise suppression. If using anything other than a resistor spark plug wire, a resistor plug MUST be used."

[Martin S.]

Dougy, Aircooled.net lists NGK plugs without the 'R' in the part number. I guess that means they are not resistor plugs. The picture shows an 'R' on the plug tho. It seems that non-resistor plugs are only good for carbs so it is no wonder they are getting scarce.

[alex d]

I had bad experiences with resistor plugs (that was with points and blue coil though), so i try to avoid them

[Martin S.]

I got my NGK BPR7HS and here's a pic. Interesting the projected tip is similar to the old Bosch, almost exactly the same.

[RaptorLou]

I like to run 7-8 of no good kind. I like the projected tip. at first I was worried about fuel wash, but after I wet flowed heads, that is not a problem on my bullet.