plugs only run second to oil threads

ya got your choices, ya take yer chances.

 

That's the exact logic I used in my boosted Mustang. Simple NGK TR6 copper plugs that I change frequently. Works fantastic.
I found a set of 6 Bosch FR6LDC on ebay for $32 shipped so I grabbed them. I'll see how they work and may go for something different based on performance.

Thanks

 

Surprised not more run iridium. In my Supra those suckers were amazing. I fouled a set so bad the car barely ran but once the fueling issue was fixed they cleaned themselves right up! No real discernible wear, the electrode was hard as nails and tough as diamonds. (Shrug)

 

iridium doesn't conduct as well as copper. ngk sets are half the cost of the bosch and can be found in most any parts store

 

Allegedly silver is better than copper (see link). Anyone ever try these Brisk plugs?

http://briskusa.com/silver_spark_plugs_brisk_silver_racing_spark_plugs

No doubt copper is almost as good (per the chart) and probably cheaper and easier to find.

 

I found a set of 6 Bosch FR6LDC on ebay for $32 shipped so I grabbed them. I'll see how they work and may go for something different based on performance.

Thanks[/quote]

I would really consider changing the coils as well for piece of mind. At least have a really close look at them and if you find any hairline fractures, change them.

 

I've tried iridium in the boosted Mustang before and noticed idle was smoother. I think it may be specific to that 4.6 motor though as they're known to have a slight random miss or popping in the exhaust on copper TR6 plugs.
However I'm constantly tuning and playing with the motor and swapping plugs and reading them frequently. Tossing $10 iridiums vs $2 copper plugs made that one an easy choice

Will definitely look them over carefully. Any doubts and they'll be swapped.

 

Iridiums advantage is it's hardness and the ability of the manufacturer to make a VERY exposed spark tip so that ignition easily occurs. It may not conduct well but it lasts and is really tough to foul. These cars with extremely long extended plug change intervals use them as a result. As I said, I had terrific luck with them on another platform and am surprised that no one uses them much on this one since plugs are such a PITA to change out. I know that some platform swear by them and some swear at them <shrug>

 

I use them in my atv and saves me headaches as its prone to using up plugs= 2007 Honda Rincon they work like a charm.

 

Denso Platinum.

 

To stay with the thread I'm going to do a plugs coil change in the next six months with Bosch plugs in OEM with Bosch coils= hey has to be one boring stock guy in the crowd lol.

 

Bosch F5DP0R

 

Yes and yes! Glad someone else also understands that conductivity is not the only consideration. The geometry of the tip itself is just as important to stable idling and ignition during load.

The other reason [drag] racers use copper is that the material is more ductile, which is more resilient to abuse (i.e. detonation and pre-ignition). Great for racers tuned to the edge of the engines performance parameters to eek out hp.

For a race car, I can understand short change intervals. But for a daily driver, or a car that sees significant mileage, there's certainly a disadvantage and risk to the head plug threads and seating surfaces (not to mention the inconvenience) in needing to change the plugs often.

 

Yeah, losing the Iridium tip can really be bad but it takes a great deal of detonation to do that normally! High exposure to the mixture is an advantage of iridium, the electrode is pretty exposed and the sharp tip allows for an easy spark. Copper electrodes round because the sharp edge is where the spark jumps and copper wears more easily. Ever higher voltages aren't always the answer and once the spark jumps you should be good. You can gap down iridiums and the exposed gap will still ignite a mixture. I used motorcycle coils on my Supra after first using LSx coils but hated plug wires - still do! If I were going to go crazy there are some marine coils that will damn near arc weld.

Swapping plugs is a hassle enough that I don't expect to experiment much though lol. If it's not sputtering I'm happy! I'll likely go GT2 spec but iridium if wear becomes an issue.

 

I run denso irridiums. They were phenomenal in my supra running a 47-88 and 47-80 on the street and track. Copper would def be better as 32krazy! said, but I don't have the time to change copper plugs as often as you need to change em.