Spark Plugs

What spark plugs do I use in my turbo or nitrous LS based engine?!

Well 99% of the time I Use NGK TR6 plug, and I gap them at at least 25 to start, because I will nearly always shoot for 20-22lbs of boost, and if you gap them around 30 you will get blowout.

we also use the BR7 EF plug when running higher hp, or over 14psi on cars without methanol, or if you just want to be super safe you can run it, fairly cold plug for low boost or low hp application, if you are in an area where its super hot or your compression is high etc might be a good choice

If you goto the parts store ask for a

Quick picture of what i like a turbo LS plug to look like

this is a pumpgas+methanol car on 19lbs, a 5.3 with a master power 70mm street car

19psi and 11deg of timing, the base near the threads is sooty and black, the porcelan is gold bown, and the electrode strap is even color with a discoloration mark in the center

there are no marks, or speckles or noisy parts of the plug, just smooth colors and shades everywhere, clean and dry, no oil, sometimes spraying methanol or washer fluid, if it has a color like yellow, blue or green, you will see this on the plug, dont be scared that it is antifreeze, its just the methanol coloring.

this photo below is one of the plugs out of my fairmont #3, a pull after 22lbs of boost, 12deg timing, pumpgas+methanol/washer fluid mix

4.8l with a 76mm turbo, plug looks awesome, 11.0 AFR on this pull little sooty but i like it that way, the motors love it.

Again what you are looking for, in the correct timing range is the mark to be in the center of the bend, ideally, i like to see it at the top of that red mark, farther away from the threads, because im my experience you make the same power from the top or the bottom of the bend, just safer at the top of course.

Reading the Heat range on the plug

fuel ring markings

for instance here is a car i recently tuned, where we had it on 7psi 19deg, you can see the annealing mark is low, going to wards the threads, we pulled 2deg out of the car and made the same amount of power, much safer tuneup, and raised the mark on the plug strap

Below is another example of what i think is a perfect reading, good color, perfect point of discoloration on the strap on a BR7EF

(spark plug shown is from John Potucek's blow thru carb turbo LS build)

this is a turbo 5.3 street car, that i street tuned on 14psi 14deg, high 10 afr to be safe, you can see its sooty and the mark is right on the bend

another turbo LS car with a satisfactory plug

E85 plugs out of my truck right on the limit of power per deg, ethanol plugs have a slightly yellow color from what i see

marks race car on E85, after running low 8s right on the money even a little conservative

here is three in a row out of camerons 9.24@150 pass on his SBE E85 crown vic

and another in the shutdown at the track