When doing ignition sparks replacement at your hemi do not miss a chance to serve ignition coils high voltage terminals and springs which are inside the spark boots. I"ve found out oxidation at mines. Just clean terminals and spring with electric parts cleaner and suitable tools.
At mine 3,5 years old jeep that simple procedure has made a definite performance improvement )
I believe that better electrical contact and less resistance leads to stronger spark and improve combustion. As it was when the car was brand new . That is actually performance improvement. ) So Ive felt positive changes in drivability.
I hope we can agree on the following, more air and fuel in the combustion chamber means more power potential. The ignition system is a vital key to ensure that an engine is maximizing its modifications. As power and rpm increases, so does the need for an intense spark. If the vehicle is stock or has minor bolt-ons like exhaust, CAI and intake the addition of high energy ignition system and related components will not add any more power.
On a normally aspirated engine with the exception of high-compression engines, there isn't a need for a hot ignition set-up due to the relative ease for the spark plug to ignite the air/fuel mixture due to the relatively low cylinder pressure. When an engine is designed by the OEM, thousands of hours of design work and testing are dedicated to ensure that each engine component will operate across a variety of engine and environmental conditions and this includes the ignition system.
Michael, just check in few years high voltage terminals at your coils when you will replace spark plugs. Then decide how it was designed.
Oxidе in high voltage ignition chain is not something that was intended to keep good spark.
I agree, oxidation will increase resistance to current flow but to what degree? Is it enough to affect drivability and performance? I'm sure OEM engineers are aware of this but I don't see anything in terms of a maintenance schedule for replacing or cleaning these components. If you vehicle is stock or has minor bolt-ons, I don't see the benefit or how it can increase performance.
Again, if you're not getting spark blowout thru your rpm band then you have enough spark energy to ignite what's in the combustion chamber.
In the end, it's your truck, your time and money. If you feel it has made an improvement to your vehicle and gives you peace of mind that's cool and thanks for sharing.
When you doing sparks plugs change it worth the time to service terminal. I meant that. Its just few minutes for each coil. I didn't mentioned about the improvements. I felt improvement. But I do not want "placebo" discussions.
Hi. Thanks for the tip on the coils. I recently replaced all the plugs in my 2011 Overland and for the first couple of weeks all was smooth again and mileage came back up.
Now the engine seems to be running rough again and mileage has dropped.
My Hemi has over 120,000 miles and I was thinking of the coils, I do not no why I didn't think of it while changing the plugs. As coils become defective they do cause a drop in performance and mileage. I've seen this on my motorcycles and other cars.