Performance upgrades

[mancheflo]

I’m looking to do a firepower ignition kit replacement here soon and was wondering if anyone has ever done one and if there’s other performance upgrades I should think about doing

[Eagle]

What year and engine is your MJ, and what is the firepower ignition kit?

[omega_rugal]

depends on your version of engine... update your signature

[Eagle]

Holy Ripoff, Batman!

 

I just Googled it. $200 to $250 for a distributor cap, rotor, and wires? The OEM Jeep coil is already a high-output coil, so unless yours is bad there is no need or reason to replace it. Save your money.

[Minuit]

I wonder what magic pixie dust they put in the cap and rotor to make the electricity go faster? 

 

Don't waste your money.

[Jeep Driver]

16 hours ago, Minuit said:

I wonder what magic pixie dust they put in the cap and rotor to make the electricity go faster? 

 

Don't waste your money.

DUI cap and rotor in brass is $27 which is about $3 cheaper than other brands......IN BRASS. 

Wires are the best on the market, bar none, will run just under $100. 

 

Kit is sold for $175 and includes coil........coil will run you $50 no matter where or what. 

 

I have wires for the 2.5, they are worth the money. 

 

 

You want quality, you pay a few bucks more......or you can buy cheap $#!&, up to you. 

 

 

But, a little perspective. 

 

 

[Eagle]

7 hours ago, Jeep Driver said:

DUI cap and rotor in brass is $27 which is about $3 cheaper than other brands......IN BRASS. 

Wires are the best on the market, bar none, will run just under $100. 

 

Kit is sold for $175 and includes coil........coil will run you $50 no matter where or what. 

 

I have wires for the 2.5, they are worth the money. 

 

 

You want quality, you pay a few bucks more......or you can buy cheap $#!&, up to you. 

 

 

The coil may be worth $50 (or not) but, unless you need a coil, why replace the OEM high-energy coil with their high-energy coil? That's just a waste of money. Just buy a new cap, rotor, and a quality set of spark plug wires and call it good.

[Jeep Driver]

3 hours ago, Eagle said:

 

The coil may be worth $50 (or not) but, unless you need a coil, why replace the OEM high-energy coil with their high-energy coil? That's just a waste of money. Just buy a new cap, rotor, and a quality set of spark plug wires and call it good.

I was not defending the concept of a grouping of parts as a 'kit', if you have paid any attention to my posts (attitude) you would know that I think 'kits' are for dummies. 

 

DUI sells the cap and rotor separately. I bought the Elchin from NAPA and paid more than the DUI. 

 

Try to find a truly custom made high quality 10mm wire set that is numbered and insulated and in a color of your choice for the 2.5 or 4.0........you cannot, so, $100 is a good deal.  (and further- you can no longer find a set with a 90 degree boot on the #1 plug to clear the AC compressor, DUI does) 

A set of Taylor wires will cost you just as much if not more and will not be insulated. 

 

 

I responded to the 'pixie dust' comment and the point was that as separate parts they are no more expensive than any other parts, grouped or not. 

 

 

And you can make what you want of this-

 

Quote

The Jeep Screamin Demon Coil allows spark plug gaps to be opened up to a whopping .065″! This larger plug gap exposes more spark in the combustion chamber for a more complete burn of the fuel mixture which increases horsepower, gas mileage and keeps spark plugs cleaner. The Screamin’ Demon Coil features a brass terminal, which is more conductive and resists corrosion longer than the aluminum terminal on the stock coil. The Screamin Demon Coil is too hot for stock plug wires so a high quality wire such as our LiveWires must be used with it. This coil mounts in the original factory location.

 

[Pete M]

gears, gears , gears.  hands down best bang for your buck.  I once watched a TJ on 40s do an epic burnout with his stock 4banger.   the right ratio will give your Jeep a big kick in the pants.

[HOrnbrod]

10 minutes ago, Pete M said:

gears, gears , gears.  hands down best bang for your buck.  I once watched a TJ on 40s do an epic burnout with his stock 4banger.   the right ratio will give your Jeep a big kick in the pants.

 

What was his top speed? 30 MPH @ 5000RPM.  

[Pete M]

not sure of that, but I'm not sure I'd want to go much faster in a TJ on burnt 40s 

 

I think he was on 5.38s?  maybe the next step up, whatever that is.  they were deeeeeep gears. 

[Minuit]

On 11/22/2018 at 10:49 AM, Jeep Driver said:

You want quality, you pay a few bucks more......or you can buy cheap $#!&, up to you. 

 

Almost five years ago, I spent roughly $30 on a "tune-up kit" with a cap, rotor, and a set of spark plug wires that are still on my truck today. The cap and rotor at least claim to have brass contacts. That very same kit is still for sale on Rockauto for $24.79 before shipping.  The #1 failure point of a cheap spark plug wire is the connectors, which on cheap wires will just break and leave the connector on instead of coming off cleanly. My "cheap $@!&" hasn't ever done that to me. Since installing that kit, I've unhooked the wires several times with absolutely no problems. Even if they did break? I paid thirty bucks. They don't owe me a damn thing at this point, and I have the equipment and supplies to put a new terminal on them myself. Besides, I don't go around unplugging my spark plug wires all day.

 

If you've read any of my posts at all you know how worked up I get about cheap aftermarket parts. I'm all too aware of the cost of buying cheap $@!&. I've been burned by cheap garbage enough times to know better. But some things don't have to cost an arm and a leg. As to the 2.5L and its A/C compressor being in the way - that's an unfortunate problem with the 2.5L. I'll give you that.

 

The "pixie dust" comment was in regards to the claims that these companies make that are often half-truths at best, and sometimes outright BS. Do I think that a "performance" cap, rotor, and wire set will make any difference whatsoever to the performance of OP's engine? Absolutely not! The only thing that those parts do is transfer a spark from the output of the ignition coil to the plugs. As far as I'm concerned, they either work properly or they don't, and the only way he'll notice any difference is if the old parts are bad to begin with. I see it the same way as I see extremely expensive speaker wires that are supposed to make a stereo system sound "warmer" or whatever adjective they're using that day. It may be high quality, but at the end of the day, it's wire. It either conducts or it doesn't.

 

Does that "Screamin' Demon" coil output a higher voltage spark than stock? Maybe. Will it let you open up the spark plug gap? If it is higher voltage, sure. Is it too high of a voltage for the factory wires? (and don't worry, they can sell you the perfect solution!) I have to admit, I kind of laughed at this, but let's just say it is. Does any of this make a real, measurable difference? That's the real question, and I'd love to see some qualitative evidence that it really does. I put absolutely no faith in any manufacturer's marketing copy unless I can find real data.

 

None of this has to do with the OP's actual question. He's clearly interested in a performance gain. I think he's barking up the wrong tree looking at the relatively well-designed ignition system for a performance gain. Eagle kindly did the Google work for me and showed that this "Firepower" ignition costs more than $200 for a cap, rotor, and wires. I spent $30 on stock replacement cap, rotor, and wires damn near five years ago and I've never had any sort of problem with any of it. I also spent $40 on a kit that included, among other things, a new Mopar ignition coil. That puts me at $70 for all new ignition parts, and they've been utterly reliable. If he's after performance, he should buy stock replacement parts and spend the rest of his money elsewhere.

 

Before he spends any money on performance stuff, though, he should make sure his engine is running properly in the first place. Start off with a check for OBD codes, then move on to a compression test and maybe clean the throttle body and IAC motor. If he's feeling fancy, maybe hook a scanner to it and see what the fuel trim and O2 sensor situation looks like. The highest voltage ignition coil in the world isn't going to help if his engine has a dead TPS and 70psi of compression on all 6 cylinders. It won't anyway.

 

There. I've said my piece.

[Eagle]

21 minutes ago, Minuit said:

None of this has to do with the OP's actual question. He's clearly interested in a performance gain. I think he's barking up the wrong tree looking at the relatively well-designed ignition system for a performance gain. Eagle kindly did the Google work for me and showed that this "Firepower" ignition costs more than $200 for a cap, rotor, and wires.

 

The $200 kit also includes a supercalifragilisticexpialidicious coil -- which, unless the OP's OEM coil has failed, he doesn't need.

[Minuit]

1 hour ago, Eagle said:

 

The $200 kit also includes a supercalifragilisticexpialidicious coil -- which, unless the OP's OEM coil has failed, he doesn't need.

You're right. I looked it up and that makes it a little less ridiculous.

 

The coil looks very, very much like the aftermarket one I took off my truck a couple of months ago, just with an extra yellow sticker. I'd be very curious about its specs, and even more curious about who manufactures it. I'd say there's at least a 50% chance that it's just some random aftermarket coil with a fancy sticker on it.

[HOrnbrod]

Lot's of misinformation here. You will not get any noticeable performance gains with aftermarket ignition components on a stock HO 4.0 engine, i.e. coils, ignition wires, dizzy cap, etc. etc. I went through many versions of "high performance" ignition parts during several dyno runs on my stroker and they did nothing for "performance" gains. The butt dyno reports above don't count, it's just wishful thinking.

 

Meaningful Jeep 4.0 HO engine performance gains come only from increased displacement, free flow headers, bored throttle bodies, i.e. suck and blow improvements, not ignition. A quality cap with brass terminals, good quality copper plug wires, and a Mopar factory coil  is the best you can do on a stock engine. The Mopar HO factory ignition system is well designed and replacing it with aftermarket garbage is a waste on $$.

 

EDIT:  And yeah - as Pete says, if you want butt dyno performance gains on your stock engine, regear.

 

 

[zomeizter]

^^this^^

 

HOrn, you beat me to it...

[mancheflo]

So love the feedback on the kit, definitely want to upgrade performance and now know that the kit ain’t worth it but how about any parts websites that are gonna have any cyber Monday deals?

[mancheflo]

18 hours ago, HOrnbrod said:

Lot's of misinformation here. You will not get any noticeable performance gains with aftermarket ignition components on a stock HO 4.0 engine, i.e. coils, ignition wires, dizzy cap, etc. etc. I went through many versions of "high performance" ignition parts during several dyno runs on my stroker and they did nothing for "performance" gains. The butt dyno reports above don't count, it's just wishful thinking.

 

Meaningful Jeep 4.0 HO engine performance gains come only from increased displacement, free flow headers, bored throttle bodies, i.e. suck and blow improvements, not ignition. A quality cap with brass terminals, good quality copper plug wires, and a Mopar factory coil  is the best you can do on a stock engine. The Mopar HO factory ignition system is well designed and replacing it with aftermarket garbage is a waste on $$.

 

EDIT:  And yeah - as Pete says, if you want butt dyno performance gains on your stock engine, regear.

 

 

So what does a throttle body spacer do? 

[HOrnbrod]

3 minutes ago, mancheflo said:

So what does a throttle body spacer do? 

 

Makes the throttle response a bit more sensitive and touchy. That's about it....

[JMO413]

I can say the bored throttle body seemed to have the most noticable gain. I know mine is a Renix but just thinking and typing. It might be in part to already having updated the injectors and later ECM. 

[Pete M]

gears.  

[mancheflo]

On 11/24/2018 at 11:19 PM, Pete M said:

gears.  

I have 3.55 gears now, what would be an upgrade from that?

[DirtyComanche]

On 11/23/2018 at 5:31 PM, Pete M said:

gears, gears , gears.  hands down best bang for your buck.  I once watched a TJ on 40s do an epic burnout with his stock 4banger.   the right ratio will give your Jeep a big kick in the pants.

 

2Lo kit.

[Swampy]

4 hours ago, mancheflo said:

I have 3.55 gears now, what would be an upgrade from that?

Depends on the tire size and your end goal. I am swapping in 5.13s because I want to have the possibility to daily drive a 2.5l comanche on 35/36s and still have the final crawl ratio to be able to do things offroad

[Eagle]

Dutch uncle here ...

 

Looking at your other posts/threads about this truck, such as the fact that the rear brake proportioning system is disconnected and non-functional, I'm going to make an unthinkable suggestion: STOP looking at upgrades and such until you have gone through the truck and fixed everything that needs fixing. Make it solid and reliable, drive it for awhile, and THEN you can take your time deciding what you really want to upgrade.