Nope. That's the beauty of these suckers--- standard socket, standard length plug with a nice long ceramic section, and they have a resistor so no worries about noise or interference. Ari at www.rx7.com recommended them to me many years ago. I think the quote was 'these babies will fire even submerged in a drum of oil' :lol:

^ How long do u get a set to last u for?

I use the NGK R7420's which is the Iridium version of the Platinum R6725's which is usually the same price... best deal I found was $33.82 a plug online.

Here's where I get the plugs:
http://sparkplugs.com/results_cross....-105&x=34&y=15
or, if I have something else to get I order them from Mazda Motorsports for around the same price.

Setup-wise I run a medium street port S5 block with S6 rotors. I use a GT35R Turbo kit from A-Spec with the stainless steel Tial V-band Hotside.
The car has put down:
340 rwhp at 8 lbs of boost
400 rwhp at 14 lbs of boost
460 rwhp at 18 lbs of boost

I was running a Microtech Lt8 with the stock coils, but I added 2 MSD Digital 6A's and two MSD HVCII coils to the leading ignition when I added the water injection this year.

-Trent

Thanks guys!

Plugs ordered today along with a datalogit.

Mike

Sorry to dig this up, but I'm having trouble finding the 6725-10's anywhere.

Where is everyone buying these?

Thanks

^ if you try to add that item to your cart, it says it is discontinued with no replacement. :(

I did, however, finally find them at summit under their part #


10's

http://www.summitracing.com/parts/ngk-3342

10.5's

http://www.summitracing.com/parts/ngk-3857

Or at least, I think these are correct for our application

I believe the 10 heat range 6725 is NLA. The 10.5, 11, and 11.5 are still available. Summit is not the least expensive option either.

Who's the best priced? I've only been able to find them around 26-27$. Online.

^ Where?

sparkplugs.com has 6725-9's for $19.99, the other heat range 6725's and 7420's are $33.

Link?

He told you, right at the beginning of his reply

Sry, but I can't find them there.

Like I've already said above, if you add them to your cart, it says unavailable with no replacement .

I've bought from this person already.

http://www.ebay.com/itm/NGK-R6725-105-ROTARY-RACING-13B-12A-20B-RX3-RX4-RX7-RX8-SPARK-PLUGS-x-4-/320981895353?pt=AU_Car_Parts_Accessories&hash=item4abc0308b9&vxp=mtr