CR10EK VS CR9EK

[yamyfreak]

I hear all the hype about the CR10EK plug has anyone tried the CR9EK plugs which is the same general number the stock plugs come with.

 

[Blue Dave]

I seem to recall someone posting test results that showed the "colder" CR10EK working better than the CR9EK ? Anybody?

 

[Wisconsin]

You're supposed to get 2-3 hp on the dyno using the cr10ek plugs. I put in CR10EIX iridium plugs and hopefully I won't have to change them for a long time. I bought the sled used and figured I'd change them just for the heck of it. While I'm at it, I might as well get the good iridiums for just a bit more on ebay than people pay for the CR10EK's. Absolutely no problems. I recommend them. If you're going to spend money to put in better plugs, might as well go all the way.

 

[motohd66]

i have tried both, and i personaly didnt see any difference. imo there is no way you will feel a 2-3hp gain, so are they worth the money?? maybe for a peice of mind. i just left the stock plugs in my s/c sled.

 

[Blue Dave]

I have the NGK CR10EK's and have had no problems in 3600 miles of use. I am not sure that I can feel the reported 2-3 HP increase but it has been dyno proven and every little bit helps!

However I believe that the question asked by yamyfreak is why run the "colder" 10 heat range CR_EK instead of the 9 heat range CR9EK's which would match the 9 heat range of the standard CR9EB's ?

The "K" denotes dual grounds for the electrode. The "B" denotes a solid cap. If you want the dual ground and a solid cap then you want a CR_EKB which is apparently available.

Switching from a single ground to a double ground in and of itself should not require going one heat range colder (9 to a 10). Therefore there must be some performance advantage to doing so or we would be running the dual ground "K" plug in the 9 heat range ?

 

[Phazernut]

The time it takes to change out the plugs is simply not worth it to me. Come on...we have 150HP sleds and we are asking for 2-3 more.

 

[tryanATTAK]

I changed to the CR9EKB's in my 07 Attak and I could not be happier. It seems to have picked up some performance and throttle response. I don't have any dyno numbers to back it up just giving you my seat of the pants and comparing it how it fared against my fairly modded 04' 700 Polaris and my buddies 05' ZR900 Cat. Before the plugs my polaris with the SLP pipe,can, air horn kit, jetted, flowrites,clutching,gearing, and stretching it to 136" would beat my Attak 3 out of 5 times. Now take into consideration my son who is about 80lbs lighter was on the Polaris. After the plugs and no other changes I can smoke him every time. My 04' Poo also had no problem beating my buddies 05' ZR 900 EFI. I could beat the Cat before the plug change but after the plug change there is no competition, I can smoke him at will even if he takes a head start. Like I said there is no dyno proof here just honest seat of the pants and comparison. Gene

 

[Blue Dave]

CR9EKB would seem to me to be the logical plug to use if you want the dual ground for the electrode and you want a solid cap. This is because it retains the OEM heat range of the factory installed CR9EB.

Therefore the question remains as to why many of us are running a "colder" CR10EK ? I am assuming that whoever dynoed the plugs tried both the CR9EK & CR10EK, and for some reason the latter proved to work better?

This makes me wonder if the slight HP gain is due to the dual grounds or the colder range or both?

 

[guardrail]

I believe it was Freddie from ECP who did the testing with his kits. I could be wrong. If you look through the 4 Stroke Air Intake section, you'll see a lot of info on them

 

[yamyfreak]

Tryan ATTAK was it only the plugs that you changed to make those gains or was it only the plugs? The other thing where did you get the plugs?

 

[Blue Dave]

I got my CR10EK's from Ulmer racing. Allen puts the threaded caps on them. If you buy them elsewhere they may not have the required threaded cap.

I am still curious however to learn if the small performance gain is from the dual ground or the colder range or both?

Allen,

I sent you a PM. Perhaps you can reply to all of us about the reason you recommend the dual ground CR10EK rather than the "hotter" dual ground CR9EK which is the same "9" heat range as the original single ground plug?

I am also curious why you do not sell the solid cap CR10EKB which eliminates the need for the threaded cap that you supply?

 

[Srxspec]

You will make the most HP running the coldest heat range of plug you can without having fouling problems. That said you will see very minimal gains from the CR9EK/B plugs (like 1/2 hp) over stock.

NGK does not offer a CR10EKB plug to my knowledge.

 

[yamyfreak]

Tryan ATTACK do you actually have the CR9EKB plugs or are you running the CR9EK plug. People want to know.

 

[Srxspec]

NGK does offer a CR9EKB plug, just not a CR10EKB series.

 

[Blue Dave]

Thanks Allen,

So if I understand you correctly, part of the very small HP gain is due to the one step colder heat range and part is due to the dual grounds?

Or is the HP due to the heat range and the dual ground just helps prevent fouling?