Delco Rapid Fire

knightrider2000 · July 8, 2003

lookin at changin my plugs. almost at 100K now.. and was wondering if anyone had good luck with the rapid fires, or some of the NGK Iridiums? Or i am open to suggestions, whats good?

Thanks

Matt G.

bigtruck21 · July 9, 2003

Hey, I used ngk iridiums in my harley and they worked great. My bike was running pretty rich and fouled out my standard plugs in 2k (should last 5k). I did some research on the iridiums, and since the electrode is tiny, the flame kernal can expand better for more spark. I noticed in my bike, it produced more power, starts faster, and the plugs aren't fouled after 1k on them. Talked to some harley techs that said these plugs are really good for rich running bikes which is much better in an aircooled engine than running lean. It also showed how it's more precise firing which smooths it out. Supposedly if a vehicle has a stock ignition that is underpowered, iridium plugs will make the most power. But ultimate power can be made with an aftermarket ignition with straight copper plugs than are overgapped according to dyno runs. So I learned my stock harley ignition is pretty underpowered, but I don't know about our trucks (but I would assume so).

silversport · July 9, 2003

Do a search, I asked about RapidFires a while back (months ago) and got some pretty good responses...it will have the numbers too...I have 'em but have not installed 'em yet...

Tucson_02Silverado · July 9, 2003

RapidFire 12.

Look on the LS1Forum and LS1tech. Good number are running them.

knightrider2000 · July 9, 2003

I have run them before.. might have helped the performance a little.. but i think they made the fuel mileage go down a couple of points in the other truck i had.. it 2 was a 99 5.3.

I was thinking of trying the Iridiums, just wasnt sure how long they would last with the small electrode they have..

Matt G.