I did a search and found that most people have been using the denso IW24 when they upgrade to a colder plug. NGK has an equivalant plug BR8EIX, but haven't heard any reviews on these plugs, Any reason why? IW24's are like $12 each while the BR8EIX is $7, Anyone out there running these NGK's? Tell me what you think about them.

 

if you get the BR8EIX plugs make sure you get the "SOLID" version. If you get the standard screw on connection ends you will get arcing accross the bottom of them. I had this problem with one of my plugs and it was causing my car to bog down. when I pulled the plugs out you could see the carbon deposits on the base of the end.

 

How many HP are you running. You really dont need a colder plug. I had the IW24 and it ran like crap. Swap them out with NGK Copper BPR7ES and it ran much better. Both gapped the same. I had soooo much carbo deposit on my Denso plugs. Plus the copper are way cheaper, 2 dollar a plug.

 

When I first started to use the IW24's, I was getting some misfires, but the water injection seems to have cleaned up the combustion chamber a bit and now I love em.

Anyone want to buy 3 boxes of BPR7ES NGK's?

Joe

 

Running close to 400 whp. I tried cooper plugs but had misfires at higher rpm. The reason for the colder plugs is hopefully to pull some heat out of the cylinder so that there is less knock. That way the car won't pull timing.

 

I would say stick to the NGK brand because of the tip design, the NGK tip sticks out more than the Denso tip and this is why I believe I had better luck at the same heat range with tuning/egt and knock. This was the only thing I could come up with and the only real difference between the two. I didn't notice a difference in testing the two plugs so this is the only thing I could come up with. Just my personal results, I don't have 400 hp either but I made the change to help with knock and summer weather. Just my opinion , hope it helps in your decision.

 

Thanks for the info. I just picked up a set of BR9EIX. We'll see how these run.