Spark Plug Debate :)

[hondarider188]

ok so I know we have all read about buying the best plugs out that get the best hp and mpg, these plugs cost more but are they worth it. So a little background as to why this comes up. Yesterday at work I decided to check a couple of my plugs that are already in the truck to make sure the mixture is good and is burning correctly. Well on the second plug I checked the insulation busted off the plug this caused me to have to buy new a new plug to replace it. well I figured I might as well replace them while I was at it. I don't know why but when I was installing one of the new plugs I accidentally broke it to:). to I had to go back to the local auto parts store and get another plug. well I had already bought all they had of the AC Delco r45ts so they recommended the AC Delco Rapid fire #2 which was the same Heat range just the nice high end plug that supposedly makes for better performance. so long story short im running 7 AC Delco R45TS and 1 AC Delco Rapid Fire #2. I will say that just by changing plugs since ive had the truck I noticed huge performance gains. so my real question is would it have been worth to me to buy the Rapid fire plugs all around for even more performance VS the regular plugs.

[Irish_Alley]

imo no, the only thing i think could benefit a engine is the heat range. nothing that i know of beside the people who get paid to say "try this plug its worth the extra 10 bucks" shows a performance gain. now if your racing or something like that then yes you want every little hp you can get. get another r45ts in your engine. idk if there is a big difference but i wouldn't risk a piston on a plug

[VileZambonie]

Is your engine stock? How were the old plugs, did you read them? Your plugs should all be the same size and heat range unless you are trying to remedy a specific cylinder issue. Your best investment in a distributor type ignition system is a complete system upgrade. The HEI came out in 1975 There's been quite a bit of advancement in technology and efficiency since then. If you are looking to truly notice a difference invest in a complete ignition system. I've had excellent results with MSD

[LTZ C20]

Don't do it! I had the same idea, "I'll put high end factory plugs in, make it better, it will be easy." I caused more problems with those plugs then when I started. I had a little misfire, changed plugs and it didn't stop. I work for a Chevy Dealer, so I went into the parts department and said I want new wires, new cap, new rotor. Did all this work and it lasted for a few days then the mis returned. I was talking to one of the old hot rodders at work, told him all I had done. First thing he said was do you have rapid fire plugs? Yes I do, he said take those pieces of crap out and put the r45ts back in. I did that and it cleared the mis and the truck ran great. Rapid fire plugs are for FUEL INJECTED engines. They work great in fuel inj. engines but carb not so much.

My best advice is toss that one rapid fire, check all your wires, cap, rotor. Also ohm out the wires if so inclined. Clean or replace as necessary. Also double check your timing and carb adjustments. That should get the best results without going all crazy and burning cash and swapping parts. 

[bake74]

Rapid fire plugs are for FUEL INJECTED engines. They work great in fuel inj. engines but carb not so much. 

     This quote is worth it's weight in gold.  When you go into parts supply houses, who are you dealing with.  OK, 95 percent of the people there just have a job, 5 percent might actually build or race vehicles.  But I degrees,  my point is those working there hear how wonderful the rapid fire is and how they can improve the performance from the salespeople who are selling them.  They want to be helpful so they suggest them to you.
     You also have to take into account the differences between fuel injected engines and carburated engines.  Fuel injected engines have a computer that makes changes depending on the vehicles surroundings, carburated engines do not.  So running a carb engine the temp and altitude can make a difference on how you purchase spark plugs.  In real high cold climate's most of the year compared to low hot climate most of the year for the same truck would take different spark plugs to run their best.

[LTZ C20]

Thank you Bake74. Bake also hit the nail on the head.

[hondarider188]

Yeah i agree with you guys that the rapid fire isn't worth it. and i don't know much about the specs on my motor only its got headers and full exhaust system, edelbrock sp2-p intake, quadrajet, I am running the stock hei ignition but with the msd street fire the P.O installed, but other than that i don't know because i haven't built the engine myself. the only reason i got the one rapid fire was that they were sold out of the r45ts and no one else in town had them or had already closed. the guy from the store said the equivalent of the r45ts was the rapid fire #2 which is what he gave me and it seems to run good on it, but i may change it just because it bugs me that one is different.

[LTZ C20]

GIT ER DONE!

[Irish_Alley]

i say get rid of your plugs ;-)

[zieg85]

Autolite, Taxi tested tough...  Been using them for years with zero problems.  I guess I am set in my ways...