should i upgrade the ignition or not? how hot should i go?

[brdhntr]

what has everyone used to upgrade the ignition on their mj. more specifically on a 2.5, but i'm interested in all the experiences. i would like to get a little more power and , maybe, mileage. i'm curious if those who have upgraded have noticed much of a difference on the 2.5 and if it was worth the money for the performance parts. also what you felt was the best as far as specifics for wire size coil output, etc..

 

in my experience, it's almost always cheaper bumping up to the performance parts over the stock anyway. i usually am partial to accel parts. i was thinking of a super stock coil at around 45 k output. wires i've used all different sizes. i was thinking of accel 8.0 wires. is this set up too hot? should i bump up to 8.8 wires? am i better sticking with a 7 or 7.5 wire (stock i believe is 6.6)? i have been using bosch platinum plugs since they came out. is this going to be a good choice or should i go with a 2 or 4 spark type plug? how hot can i safely go?

 

i've used msd alot as well as some flame thrower stuff as well. to me, it just didn't seam like a difference worth the price. the accel has always served me well on all the vehicles i've used them on.

 

the vehicle will be used on the highway alot and as a dd so it has to be very reliable. i don't want to change things if it's going to cause problems in the future. a little extra power and mileage would be great.

 

just so you know, my k&n is already ordered and on the way.

 

so, what do you all think? :popcorn:

[jeepcoma]

Not sure how much is available for the 2.5, and how much of a difference it will make. For the 258 the GM HEI conversion was pretty popular (I did it to mine, really loved the results) and I plan on seeing whether the same conversion will work for the 4.0. There might be a similar route you can take with the 2.5 but it might not have much effect (if any).

 

I wouldn't bother with multiple prong plugs, just stick with some quality platinum plugs (for longevity) or super-fine tip iridium plugs... if you notice a difference with standard good plugs vs iridiums, then you may in fact have something to gain by replacing a stock or tired coil and wires. Of course, if you're replacing worn-out stock components, you'll notice improvements whenever you replace it.

 

I think any real measurable improvements will be difficult to come by though, and very pricey. You'd probably need something like the MSD control module and all supporting accessories to go with it. For the money, I think you'd be better off improving the exhaust.

[brdhntr]

For the money, I think you'd be better off improving the exhaust.

 

 

what specifically are you thinking on the exhaust. i was going to make a custom one this spring with a magnaflow muffler.

[Pete M]

Best bang for your buck on the 2.5 will likely be removing the stock radiator fan an installing an electric one. Other than that, gears, gears, gears, gears, but that isn't typically cheap. What axle ratio do you have now? 2wd or 4wd? Tire size?

[jeepcoma]

Best bang for your buck on the 2.5 will likely be removing the stock radiator fan an installing an electric one.

 

That's a great suggestion, the old fans suck down quite a bit of HP. Going electric will probably have a noticeable affect on highway fuel economy if not power as well.

 

As far as exhaust, ditching the stock manifold for some shorty headers (if there are even any made for this engine) and replacing the crush bend pipes with a nice 2.5" (maybe 2.25" or 2.75", you'd have to do some research for the optimal size) mandrel bent system from start to finish, and a quality cat and muffler will probably give you some noticeable improvements.

[HOrnbrod]

Best bang for your buck on the 2.5 will likely be removing the stock radiator fan an installing an electric one. Other than that, gears, gears, gears, gears, but that isn't typically cheap. What axle ratio do you have now? 2wd or 4wd? Tire size?

 

:agree: And since the radiator on the 2.5 is basically square, unlike the rectangular 4.0 rad, it will be much easier to mount an electric puller fan that will cover 80% or more of the radiator and provide good cooling. :cheers:

[Pete M]

Be careful with the exhaust, especially with a 2.5L. The stock engine is designed around a certain amount of backpressure. If you free up the exhaust too much, you can gain some top-end HP, but lose a lot of low-end TQ.

[wolfpackjeeper]

Ive heard good things about a flywheel weight, but I have never personally used one. For the Ignition, I would look at getting a stock style MSD coil, a nice cap and rotor with brass terminals, and some good wires. For plugs I would Use a good champion copper plug, OR I have had great luck with NGK V-powers. Use a good filter, and when you do the exhaust get a nice muffler and a good quality CAT.

 

I was thinking 4.0 stroker swap. But I think I may just see how far I can take the 2.5. Go with a good internal rebuild, premium rings and such, probably with an overbore. And rebuild it strong enough to take some boost or nitrous. At this point thinking a set of long tubes to build up the torque curve and a remote mount turbo pushing about 6psi. Plenty of room under the truck and bed since it is a 2.5.