Im moving to 10EGV's tomorrow.

 

Spark plug reading

Good reading. Proper way to select the right heat range plug. Grounding strap and heat on the plug threads.

Article also says something to the effect about a cdi box keeping the plug clean even though the plug is too cold.

 

Is BUR9EQ ok for 400-450whp @ 15-17psi?

 

Here's my experience with the BUR9EQ, BUR9EQP, NGK R6725, and NGK BR10EIX

BUR9EQ: cheapest. Confirmed safe up into low 400s, at least with the way I tune cars. Least expensive. Doesn't last very long--definitely 5000 miles or less if you are using an ignition amplifier.

BUR9EQP: close in price to BUR9EQ. Confirmed safe up into low 400s, at least with the way I tune cars. Lasts longer than BUR9EQ.

Both of these are a little more resistant to fouling due to slots and surface discharge design.



BR10EIX: cheap 10 heat range with irridium. Pain in the *** because they require an expensive thin wall socket. If you make a DIY one with a grinder, you are risking something going wrong. These are lacking in durability in my experience; I cracked the porcelain on a couple sets. I've found a BUR9EQ will hold up better than one of these.

NGK R6725 10.5: very expensive but work with a conventional socket. They definitely hold up longer than the other plugs.

Both of these sets of plugs have noticeable loss in idle quality and low load driving. I have done back-to-back swaps with these running the exact same tune, and had to add significant fuel to get AFR's from being too lean. Basically, brake specific fuel consumption increases in around-town driving. If you do foul them, you're probably out a lot of money.

I think people underestimate just how cold the stock heat range plugs are. I mean that is REALLY cold plug. There are a lot of piston engines with very high exhaust temperatures making a lot of power with a combustion chamber pressure that only run 7's or 8's.

 

I also cracked the porcelain on a couple BR10EIX plugs.

Never had a problem with the EGV's. Worked good for me but was a pain to install and remove. Found an alternative plug that utilizes a 5/8 socket, cheaper also.

 

Tried these plugs for awhile, no problems. required 21mm thin wall socket. Went 145mph a few times. 2600lbs car



Now giving these a try. Cheapest plug yet, no issues.

 

what about the r6254k-105 they are very similar to the ones above.

 

Looks good.
What plugs were you running before you took this photo of the housing?

 

If you are running water injection, you can go .5 to 1 higher on the heat range.

 

True but don't forget that those same plugs in a piston engine get a cooling off period because they fire every other rotation of the crank (unlike in the rotary's).

 

^^^^^^ been using these for the past 11 years or so, first on my turbo honda then on my rotary (500+rwhp) Nothing but good results to report. They are also long lasting. I use 10's all round.

 

Where did you guys get the thin wall socket?

 

I just used a grinder for the 21mm plug socket.

The V-power plugs use a 5/8 socket.

 

They don't idle / light load as well as the cheaper plugs in the same heat range?

 

i played with a bunch of different plugs in the P port, and basically noticed the same thing, different plug designs want different fueling at idle/ low speed.

with heat range i see no problem in going to 9's in the leading and running 10 or 11 in the trailing, essentially stock but colder

 

You didn't have any issues with these plugs since they have about a 1/4" shorter reach than normal plugs?

 

It's only 2mm. 19 v 21. Personally, I prefer the 21. But these guys are having good luck with the shorter plug and they are a lot less expensive.

 

To be 100% honest about possible issues with the shorter plugs, how can I can say either way, bad or good. My gopro camera wont fit in the combustion chamber for me to visually see whats going on in there. All I can say is, I have never once questioned them as a possible problem and will continue to use them.

 

Well said^^^ There's plenty of great information on this tread to help anyone decide on which sparkplug to use.

 

Chuck,

Let us know if you have issues running the non-resistor plugs. Looking at it from the engine management side, running the non-resistor plugs is not a good idea.

 

I'm going to order up some of the 6252s and give them a try. Looking at the tip versus the 6725, even though the reach is 2mm less on the 6252, it has a projected ground strap and electrode versus the shrouded parts on the 6725. So the spark kernel is less shrouded and in close to the same place relative to the rotor. The next debate would then be over the nickel coated, copper 6252 versus the platinum 6725... Good find Chuck!

6252




6725

 

100% agree with you, a little bird by the name of Ari Yallon told me many years ago that he does not recommend using non-resistor spark plugs due to noise/interference with the FD's CAS system.

I've posted many times against the shorter snowmobile/motorcycle plugs, and even tore down an engine that had ran them for years and had severe rotor housing damage.

Btw Chris, looks like that spark plug site doesn't allow hotlinking of pics..... you may have to DL the pics and upload them here.

 

so your blaming the plugs for the cracking around the spark plug hole? Cracking around the plug hole has been a issue long before anyone started using the shorter plugs. could the tune have caused cracking of the housing. I've seen cracking of the housing on motor that have run the "correct" plug. It's something that is going to happen sooner or later depending on how hard the motor is being pushed.

Who is Ari? he said it could cause noise but did he say the shorter plugs "WILL" cause cracking around the plug hole? Anything could cause this issue but to say the shorter plug is the sole reason...???? just wondering.
Yes some ecu don't like non-resister plugs. Tech GT for one. (ask me how I know) But the v-power plugs are being used by lots and lots of people with different ecu's with great success. I am not advocating the shorter plugs, just throwing something different out there.

Iv'e also tried removing the sealing ring from the shorter plug. I am a lazy sob and no longer do that. This put the plug directly on the housing and found the plug was hard to remove after a few runs. Just took more effort to remove them, vs with the sealing ring.

 

Weird. I see them, probably since their in my cache. Anyway, if a mod could edit my last post and insert the pics, that would be great.

 

You're a rotary drag racer from TX and don't know who Ari is? Unsure if joking.

Drag racing vs road racing vs street driving are such different applications it's almost worthless to make comparisons of something like spark plugs among cars used for those different kinds of driving IMO.