7 replies to this topic

[BlueJay73]

1999

NGK BKR7E      gap is preset at 0.036 in.

NGK BKR7E-11 gap is preset at 0.044 in.

NGK BKR7EIX-11 gap is preset at 0.044 in. (iridium)

 

I see that these are popular plugs among SM racers.

Which is better?

Does the gap matter?

[Steve Scheifler]

If your ignition and fuel systems are working properly you won’t notice any difference between these or any number of equivalent quality plugs. We have carefully tested $2 Bosch Platinum with six weekends on them against new NGK iridiums and found zero measurable difference. Much more important is to learn to read plugs and pull them out occasionally for inspection.

[tLinder]

If your ignition and fuel systems are working properly you won’t notice any difference between these or any number of equivalent quality plugs. We have carefully tested $2 Bosch Platinum with six weekends on them against new NGK iridiums and found zero measurable difference. Much more important is to learn to read plugs and pull them out occasionally for inspection.

Steve, any opinion on plug wires? (I've used Nology, which are more than enough for me)

[Steve Scheifler]

Steve, any opinion on plug wires? (I've used Nology, which are more than enough for me)

Excellent question, similar answer but with caveats. If the ignition and fuel systems (and tune) are otherwise good then the only meaningful difference between quality plug wires is how well they stay on the coils and how long they last before arcing to ground through the insulation. We’ve seen multiple sets of the popular blue wires (NGK and Taylor as I recall) last only a couple seasons. I’ve never had problems with Magnecor. If you can tolerate the shameless self-promotion and badmouthing of the industry at large, their website does provide some insights:

https://www.magnecor...necor1/main.htm

[Tom Sager]

Steve, any opinion on plug wires? (I've used Nology, which are more than enough for me)

I think your engine builder would have an opinion on this.

[tLinder]

I think your engine builder would have an opinion on this.

He does and I trust / believe in him, just thought I toss it out there

[Steve Scheifler]

He does and I trust / believe in him, just thought I toss it out there

I have no idea who that is so nothing personal when i say that engine builders are not immune to being convinced of things that won’t stand up to scientific method.

The thing that’s important about our engines is that they are essentially stock, relatively low performance and well engineered. As race engine go, with low compression, mild cams, four cylinders, dual coils, fuel injection, modest RPM and ECU control there is nothing tricky about igniting the charge and getting a good flame front IF all system components are working as designed. Crank up compression or add boost, rev to 9k etc. and the ignition system requirements increase, but these are not that. But hey, I’m always open to facts. If an engine builder or anyone else can provide data or even a convincing explanation I’m interested and would gladly spend the time testing it on the dyno.

[Dave D.]

For the price of the popular blue wires( I use OEM on VVT), I find no problem replacing every few years as normal maintenance. I have yet to have the simple OEM NGK wires pop off(IF installed correctly).