oddball said:

notoriousDUG said:

How can a motor 'not like' a platinum plug?  A platinum plug should show no real change in performance, it is not to make the plug work better but to make it last longer, f'n things are a waste of money if you ask me…

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I wondered the same thing but there are literally dozens of Rubicon owners who all agree the platinum plugs don't work well in their 4.0's  and since the overwhelming majority say not to run them, I'm not going to.  End of story.
 

I believe the Rubicon forum is where there was once a guy telling people he could feel the loss or gain of 3HP as well so I take everythign there with a grain of salt.

Moot pointbecause they are a waste anyway.

One thing to keep in mind when you are getting down to making motors for off roading is the type of power you want and why.

Unless you are planning on becoming a mud runner desert racer you want the power band low and don't really need a ton of power, you need tons of gearing.  Some of the early winners on the rock racing circuit with 4 bangers with inertia rings and crazy crawl ratios; even today light rigs with steep gears are doing just as well as a pig of a rig with a fire breathing V8. 

But then again what works rock racing and what works wheeling for recreational purposes are two entirly different things…

Some of the best wheeling rigs I have owned and know when it comes to just wheeling for fun used stock motors!  My CJ-7 with a tired 258 and stock gears worked great.  Cooter's TJ is still a bone stock 4.0.  Zach's insane Samurai uses a factory 4 cyl with stacked t-cases.  JoeZ ran his 'runner on a 42" tire with a stock 22RE.  Tom at the Cliff's runs stock motors in his samis with deep t-case gears.  My 6.2L diesel Blazer was awesome and made like 90HP on a good day!  I had a XJ with a fire breathing V8 and in some cases I think it was more of a pain then it was a help; if I built that again I would have kept the 305 that was in it when I bought it or found a starter rig with a 4.0 in it and used the SM465 behind that.

The poop you see on the internet videos and in the pictures is awesome, but it's comp stuff and wheeling like that in trail groups is just stupid; there is no reason for it so why spend the money for power you may never use?  You want a really fun rig that is a joy to drive and fun on the trials?  Keep it tuned up and well maintained and put all the speed parts money into gearing and parts to make the suspension work better and you will get many, many times the bang for your buck and far more enjoyment then you ever would from the performance mods.

Strong motors cost money, take more maintenance and are more fickle when it comes to behavior; why add the headache when you could just build a sweet rig on a stock motor that will never hurt for power if you drive it well?

You will see more of your power back in traffic from a re-gear then you will ever find messing with the motor.  I would take a 2.5 w/ 4.56 gears and 35's over a 4.0 w/ 3.73 gears as a daily driver; that's real talk.  You want the best of everything 4.56 that thing now on the 33's and just get used to not going fast on the highway.

Plugs I recomend Delco but as long as youa re buying a name brand premium plug you are not going to go wrong, just stay away from 'novelty plugss'

You want to make real power with the 4.0 do the same stuff you would to any motor for low end grunt but in my opinion with the HO 4.0 you are really not going to see any real gains without real mods to the engine, bolt on stuff is not going to do much for you they are a pretty well optimized engine as it sits.

ktraver97ss said:

Cool beans, thanks for the help.  If Im gunna re-gear Ill probably wait and choose my gear when I go D60/14bolt.  My reasoning behind that is if I do gears, im gunna do lockers, if I do lockers, im gunna start breaking axles, so until all that is planned and ready Ill just keep her running strong.

What gear ratio comes in my 03 Sahara stock?

The whole axle snapping thing is nothing but lies perptrasted by bad drivers.

Cooter ran locked on a D30 with 297 joints running 4.56 gears and a Q78 (36x10.5x15) and has, I am pretty sure, never broken an axle.  Remeber the u-joint on a late model D30 is the same as that on a D44 and the shaft diameter is almost the same as well; your real weak point is the ring and pinion compared to the D44 and when was the last time you heard of a D30 R&P blowing?  Plus if you compare a high pinion D30 to a D44 you are evening things out even more.

The D35 is weak but you can make it live, I have seen them live with a 35 or 36" tire for a surprising amount of time and with the ease of a D44, 8.8 or 8-3/4" swap you can have the proper width and bolt pattern for next to nothing; heck you can even buy all kinds of bracket kits for it and not have to make anything yourself!  I don't think Cooter has broken anything on the D30/8-3/4 combo he runs and he didn't even need to change his wheels!

Unless you are planning to run a 38" plus tire there is just no call for thatkindof axle nonsense.

FYI, if you have a YJ disregard all of that because they have a very low airbox intake and tend to suck water.

Actually I think the air box on a TJ is to low and an open element on a short tube up high with a splash guard is a better idea. 

I would be interested to see the filter data because if the filters are of the same material you should see the same filtering capability regardless of shape and location.