3.7L Performance

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K9JEEP

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Oh I see thats the GVWR. But where does it say the actual weight?

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Boomhawr

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My sticker on the inside of my driver door says my rig weighs 5600lbs. Where are you guys getting 4300 from?

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Maybe you just feed yours to much and it needs to go on a diet. :happy175:
 

K9JEEP

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Maybe you just feed yours to much and it needs to go on a diet. :happy175:
Feeding it too much gas haha. So I was thinking this thing was 5600lbs but more like 4400

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2002KJLimited

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Does anyone have the DUI S.O.S ignition coils, I may buy some and want to know how they perform. I know you can open the plug gap a lot with them.
 

tommudd

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Does anyone have the DUI S.O.S ignition coils, I may buy some and want to know how they perform. I know you can open the plug gap a lot with them.

For 225 bucks they better do real well.
But again the computers not going to give up much if any unless you reflash it.
I wouldn't see that they would be worth installing .

Still trying to make a race horse out of a pig..............:icon_razz::icon_razz::happy175:
 

JeepinJarhead03

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i put a set of 80kv granatelli's on a grand cherokee drag jeep, they ran the guy about 750 bucks for the set, it was about 5hp net gain on the dyno, he shaved a few hundredths of a second

thats junk you do when everything else has been done and redone
 

tommudd

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Thats when you are down to getting that last little 2-3 mph at top end and knock a couple of seconds off your ET
 

renegade 04

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Has anyone tried a cowl air intake or going with non resistive spark plugs? I really want to try the cowl air intake to make more run under the hood and to lower intake temperatures.
 

tommudd

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Has anyone tried a cowl air intake or going with non resistive spark plugs? I really want to try the cowl air intake to make more run under the hood and to lower intake temperatures.

Cowl intake would be hard to do, I have sat and drawn up plans but not much room in that area. Plus you'd actually have more piping under the hood and have to be "S" shaped to do it ( just my opinion )

From NGK

NGK strongly recommends using resistor spark plugs in any vehicle that uses on-board computer systems to monitor or control engine performance. This is because resistor spark plugs reduce electromagnetic interference with on-board electronics.

They are also recommended on any vehicle that has other on-board electronic systems such as engine-management computers, two-way radios, GPS systems, depth finders or whenever recommended by the manufacturer.


In fact, using a non-resistor plug in certain applications can actually cause the engine to suffer undesirable side effects such as an erratic idle, high-rpm misfire, engine run-on, power drop off at certain rpm levels and abnormal combustion.
 
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JasonJ

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From NGK

NGK strongly recommends using resistor spark plugs in any vehicle that uses on-board computer systems to monitor or control engine performance. This is because resistor spark plugs reduce electromagnetic interference with on-board electronics.

They are also recommended on any vehicle that has other on-board electronic systems such as engine-management computers, two-way radios, GPS systems, depth finders or whenever recommended by the manufacturer.


In fact, using a non-resistor plug in certain applications can actually cause the engine to suffer undesirable side effects such as an erratic idle, high-rpm misfire, engine run-on, power drop off at certain rpm levels and abnormal combustion.

^ I've seen this happen on newer vehicles... was so strange... and then the owner put the correctly spec'd spark plugs in and it was as if a switch was flipped.
 

tommudd

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^ I've seen this happen on newer vehicles... was so strange... and then the owner put the correctly spec'd spark plugs in and it was as if a switch was flipped.

A lot of what people try to make any newer motor run better/faster/ whatever is hold overs form years ago. Lot of the things that used to work just don't anymore due to all the electronics, but yet they persist in trying or saying it will work.
Just like TB spacers for one example, argument on Facebook a while back, kid swore up and down the spacer gave him a ton of extra horse power and mileage LOL
 
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J33Pfan

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how about just getting great gas mileage??

can we get a Sticky on Gas Mileage Improvements??
 
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J33Pfan

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^ I've seen this happen on newer vehicles... was so strange... and then the owner put the correctly spec'd spark plugs in and it was as if a switch was flipped.

I always thought you need Resister plugs because of the High Energy (high voltage) Ignition Coils need that to make a proper spark.
 

JasonJ

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I always thought you need Resister plugs because of the High Energy (high voltage) Ignition Coils need that to make a proper spark.

Nope. I believe originally they were intended to reduce/eliminate ignition noise that was heard as feedback through car radios, mainly AM band.

Ignition coils output between 35,000 and 50,000 volts coming off of the secondary windings... the few ohms of resistance that a spark plug presents is a speed bump on the highway for the ignition coils... barely noticed.

20-21 at 75 plus on the hiways and the way I drive, lifted , heavier skids isn't bad, what do you get ?

I see 23-25mpg at 55mph cruise set; 72mph cruise enabled I routinely get 20. With 4WD modes enabled it goes down, obviously.. new AT tires, otherwise I'm as stock as it gets at factory build weight. I drive conservatively except for the occasional need to get my **** moving on on-ramps.
 
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tjkj2002

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Ignition coils output between 35,000 and 50,000 volts coming off of the secondary windings... the few ohms of resistance that a spark plug presents is a speed bump on the highway for the ignition coils... barely noticed.

Actually it's really noticed.

You want to run platinum plugs you need to increase the plug gap from 0.040" to at least 0.060" to have the same resistance as a nickle/copper plug.For iridium you need to increase that gap to over 0.080",that's twice the gap as nickle/copper plugs.

Then you gotta deal with heat range which is hard to do with platinum/iridium plugs.

Besides those types of plugs were designed for 1 sole reason,longer service intervals on V6/V8 transverse engine vehicles that are labor intensive to change the plugs(2+ hours,some call for over 5 hours).There ignition systems were designed around those plugs.It takes less then 20mins to change the plugs on a 3.7 V6 KJ.
 

JasonJ

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Actually it's really noticed.

You want to run platinum plugs you need to increase the plug gap from 0.040" to at least 0.060" to have the same resistance as a nickle/copper plug.For iridium you need to increase that gap to over 0.080",that's twice the gap as nickle/copper plugs.

Then you gotta deal with heat range which is hard to do with platinum/iridium plugs.

Besides those types of plugs were designed for 1 sole reason,longer service intervals on V6/V8 transverse engine vehicles that are labor intensive to change the plugs(2+ hours,some call for over 5 hours).There ignition systems were designed around those plugs.It takes less then 20mins to change the plugs on a 3.7 V6 KJ.

I think we'd have to compare the same copper plug, one resistor one not. I've played with both variants a lot in recreational vehicle engines, jet ski's, snowmobiles and such.

But yes, when you consider platinum and iridium plugs, it becomes a more significant difference.

I recall seeing some transverse engine designs that nearly called for the entire engine cradle assembly to be dropped in order to change spark plugs. Or where the whole upper intake plenum needs to come off... horrible.
 

tjkj2002

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I recall seeing some transverse engine designs that nearly called for the entire engine cradle assembly to be dropped in order to change spark plugs. Or where the whole upper intake plenum needs to come off... horrible.

I know I get the pleasure of changing said plugs on a daily basis.

Try a F-body Camaro,those back 2 plugs will make you want to never buy a GM product again(really doesn't take much for that decision though) and beat the engineer to death.
 
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