sleeper7

Around 6$ from rockauto. Resistor plugs.

sk8world

iTrader: (5)

Is the thread pattern shorter?

sleeper7

They are shorter then stock plugs and require a thin wall socket. Making your own with a grinder is easy.

http://www.sparkplugs.com/results_cr...d=2396&x=0&y=0

just startn

iTrader: (33)

How much shorter than stock plugs? They look real short. Can we get a comparison pic? Whats the heat range?

sk8world

iTrader: (5)

Is there any direct effect from using a shorter plug? Could that cause faster cracking around the plug holes?

RXTASY57

iTrader: (2)

looks like the heat range is 10.5
Says on the webiste the reach is 3/4" which is just like the RE11's from NGK
What about gap?....what you all gapping them at or do you just leave them the way you get them?

NoPis10

iTrader: (29)

I run NGK Iridium BR10EIX. They cost $6 at the local Advanced Auto....

I am actually looking to try different plugs because these DO NOT last. They seem to foul out after 2 outings at the track and I am getting tired of changing plugs so often... I am running VP C-12 race gas...

If any of you have a suggestion for a longer lasting race plug I would be greatful..

L8R

C. Ludwig

iTrader: (27)

sparkplugs.com says that R6252 plug is a 19mm reach. Stock and the 6725 and 7420 plugs are 21.5mm. Gap on the R6252 is .060"! The 6725 and 7420 is .028".

Personally I hate the thought of using the shorter plugs and just asking for carbon to build up in the void only to become a nice glow plug like heat riser.

You spend 3k+ to build an engine. Is an extra $100 a year on the right spark plugs really such a bad idea?

RotaryEvolution

iTrader: (30)

less reach = more pocket for compression to increase the chance of seal lift off as well.

would be lovely if NGK made a colder surface discharge plug for us... i'm putting it on my xmas wish list.

sk8world

iTrader: (5)

I agree. Just like fuel. I don't skimp. Would love to buy plugs for $6 and q16 for $5 a gal.

Trots*88TII-AE*

iTrader: (11)

They do. http://www.ngk.com/results_cross.asp?pid=BUE

Reach is ~1.5mm shorter than stock, but you can overcome it a little bit by replacing the crush washer with a flat spark plug washer, and tap the rotor housing just a little bit further. It is still a bit more recessed than stock, but there are no protrusions (ground straps) to become hot spots.

Note: I haven't used these yet, but I was messing around with an old rotor housing to get them to fit better, and would like to try them maybe this year.

sleeper7

This is as important as getting the heat range correct, if not more important.

The correct gap depends on your ignition system, cylinder pressure and tune. IMO

PS good luck to you guys always buying the "best" parts and always doing thing the "right way".

RXTASY57

iTrader: (2)

Thats a lot of variables.
I am running Mercury coils and E85 at around 2 bar of boost.
Would you want less gap or more gap?

sleeper7

I gap my plugs at 19. could go bigger but trying to push 40psi and over 700rwhp. Using stock coils with 15$ plug wires.

Maybe start at 22 and see how it runs. Go smaller gap is misfires happen

These also show a 19mm reach so I may try a set of these. The Kansas City guys are pushing the limits. !!!

AlexG13B

iTrader: (7)

wat kind of average mileage u guys getting out of race plugs on DDs?

RotaryEvolution

iTrader: (30)

the wider the gap is, the more likely it will blow out and cause ignition breakup earlier. ideally you want the largest gap that still gives no breakup.

sk8world

iTrader: (5)

Thanks, Been working perfect. In fact this is my 4th season on the same motor

NoPis10

iTrader: (29)

How are you gapping those NGK 2396 ?

Looks like they can't be gapped....

Bacon

iTrader: (12)

LMAO I thought i was the only one!.... I would have to swap them after like 6-7 passes, and was like you've got to be kidding me! was worse with the EGV's that was when i ran c16, but then i changed ignition setups and will go back to good ol 9's all arround for this season

AnthonyNYC

iTrader: (3)

I run the 11.5s and I have been looker for a cheaper way for a while now worried to use the shorter plug as you guys mentioned. After repeated passes have you guys seen the ceramic in the plug develop very tiny hairline cracks?

How much boost are you planning on running with the 9s all around?

RXTASY57

iTrader: (2)

I went ahead and bought some Greddy Pro RE11's. I will just swap them out periodically and clean them with my blaster.
After hearing all the replys, I think that is my safest bet.
If it ain't broke, don't fix it. So far they have worked very well for me.
I wouldn't run more than 17 PSI on 9's.

sk8world

iTrader: (5)

Good move! You get them from ari?


Anthony, Mine alway get those cracks. Usually the leadings crack first after 5-7 track events. When they are small I keep running them but once They get larger I toss them.

AlexG13B

iTrader: (7)

Im just worried of the blasting media ruining the platinum/iridium

Gilgamesh

so let me throw a wrench in here.

what if im running a formula mazda where 5hp matters, and i just cant fork over the money for the race plugs, but ive ran rx8 trailing plugs all around.... (which are shorter in length) but looking for a cost effective way to have multiple plugs on hand for an entire race weekend.

whats the advantage of running a colder plug on an NA motor?

Bacon

iTrader: (12)

Didnt notice any cracking, but ill look through my Bag-o used plugs, some are toast, or have 1 pass or just 1 pull on them!! When Wilmerantic called NGK they said the 5777 is good for 30lbs and below, then their race plugs above 30, said there are alot of guys who warm up on the 5777, then switch to raceplugs for their passes.....depends on fuel, tuning, exct...
I dont plan to run alot of boost this season

Just remeber everone your tune is for the plugs you tuned on, going to a higher heatrange/ different plug length can and WILL affect tune/power outpt