Mark923

For those JK owners that may be interested, engine performance improvement was noted on my 2009 Sahara Unlimited with 2000 miles on it after changing the OEM spark plugs to Bosch Fusion IRs and changing the plug wires to the Granatelli MPG "0" ohm plug wires.

It will be some time before an actual MPG improvement can be determined, but for local driving there is a noticeable improvement in engine starting, acceleration, and not as much downshifting in the auto trans on grades.

It took only a few minutes to change the engine left side plugs and plug wires, but it is tough to access the plugs and re-route the plug wires on the right side of the engine. But so far it looks as if the project was worth the time and expense.

It was also interesting to measure the ohms in the OEM plug wires and find none were the same. They measured from 3,800 to over 11,000 ohms depending on the cylinder.

ALL of the Granatelli MPG plug wires measured "0" ohms.

These two additions to the K&N Filter should give better engine performance.

33 williys 77

Without getting into to much electrical theory

One of the byproduct of an amp is heat whether its jewles, milli, or amp
Running zero resistance plug wires, you are allowing the coil to deliver full load
which in turn makes the coil run hotter, shortening its life, so there is a trade off here.


33

Mark923

Right! Thanks for the heads-up on the trade off.

Removing the resistance from the OEM wires moves the JK ignition a little closer to the coil on plug ignitions used on some Chrysler, GM, Toyota, and other engines. The coil on plug ignition system is essentially the same as other ignition systems, but without the wires. Each coil has low primary resistance, about 0.4 to 0.6 ohms with Chrysler, and steps up the primary system voltage from 12 volts to as much as 40,000 volts to produce the spark for the plug.

The difference between coil on plug and other ignition systems is that each coil is mounted directly atop the spark plug so the voltage goes directly to the plug electrodes without having to pass through the plug wires. It is a direct connection that delivers the hottest spark. It appears the Granatelli MPG wires are very close to the coil on plug system to get a hot spark for ignition, without having the cost of a full ignition upgrade on the JK, that is if the owner of the JK wants better ignition and a smoother running engine.

dream catcher

I would agree with you on the IR Fusion plugs, I changed to the IR fusion plugs shortly after getting my 2007 JK. I tried CAI and Computer programers which in my opinion are not worth the drop in gas milage that I experienced, I took the CAI off and went back to the stock computer program and still run the IR fusion plugs with a KN replacement filter and a throttle body spacer.
I will give some thought to the "0 resistance plug wires"

derff96963

The issue however is that they make the two types of coils differently. The Coil on plug is designed to handle the "Zero" Resistance and will be made to keep itself cool. However the standard coil is not meant to have a zero Resistance load and might overheat. I am not saying it will fail right away but the potential is there. You might want to make sure atleast know where you can get a new coil in the case yours fries.

For example I has a similar thing happen in my CJ. It came with the 2.5L 4 cylinder engine it in. When I bought it I swapped in the stock 258cid I6. Well I kept frying ignition coils. I even boiled the oil out of an Accel Super Stock Coil. Well it turned out the stock 6 cylinder engine had Resistance wire from the ignition switch to the coil dropping a couple of volts before it got to the coil. The Coil was not meant to run off of full voltage. Instead is only wants around 9-10 volts.

My stock 4 cylinder used a different coil design that wanted full voltage so no resistance wire in mine. I put in a Ballast resistor and its been fine ever since.

Just something to keep in mind.

BadTime

I tend to doubt the gains from this kind of stuff, but I am surprised at the resistance variation in the plug wires. That would truly have to be some low quality wire. Any chance you were not getting good measurements?

iannis

Switched from OE to Granatelli MPG Plus zero-resistance spark plug wires last week,quite a task considering the tight space passenger side, and everything runs smoother and it seems that the engine has gained power as well. Attributing to the aforementioned power gain must be the K&N filter,inbox, used.
Overall I must admit that the quality of the OE plug wires is very low and the reason Initially looked for replacement was the fact that during my last visit at the dealership whilst the mechanic changed spark plugs he ruined one of the plug wires, due to the fact that he couldn't pull it of place easily.

Overall rule of thumb is that upgraded spark plug wires will offer better spark and therefore producing a better burn of the air/fuel mixture and thus contributing to power gains plus fuel economy.

CalebSC

I have had the Granatelli wires on the my 08 Wrangler X Automatic for over 2 months. The only issue I have is I get a little pop in the radio. I talked to the folks on the tech line they gave me a few ideas and stated they would check with the "main guy" and call me back. Still waiting on the call . I did pick up some MPG's. Approx 1 to 1.5 MPGs. I want to change out my plugs. Any ideas for a high quality replacement plugs? Type ? Brand? Thanks

flounder

I was looking at those plug wires for possible purchase but I didn't believe u gould get power just by changing wires but it worked for u so Im gonna try em. x2 on the plugs how bout e3

A/C Guy

You are comparing apples to oranges here. Your problem was due to the input voltage; a primary side issue. They are talking about the secondary side; output side. A coil is a transformer. The total output is measured in KVA. Going to 0 ohm wires will not short out or over load the coil. The spark still has to make the jump across the spark plug gap, that is enough resistance to limit the load on the coil. The only drawback to 0 ohm wires is you will get radio interference. Just like the other post stated. The engineers know the only way to stop the static interference is to add a resistor. That is why they haven't and won't call back. That is also the reason car manufacturers always use cheap quality, high resistance wires; they are quieter, no RF issues. Straight wires are cheaper to make, but you will always get RF static.