99 Sahara Upgrades - JeepForum.com
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post #1 of 5 Old 08-12-2012, 08:29 AM Thread Starter
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99 Sahara Upgrades

My nearly bone stock 99 TJ is about to get some performance upgrades. I will admit up front that other than a few trips along a gravel driveway my Jeep has no clue what "Off Road" means. I suspect that there are a lot of Jeepers out there like me. So I look back on my years of Mustang performance mods (everything from a 1969 428SCJ Convertible through a 1997 Cobra and 11 others in between) and have been beating my head against the wall trying to figure out what is and is not worth it on this 4.0. Reading forum posts is like reading religious debates – with opinions often being polar opposites. Even the "Experts" can't keep their story straight... Case in point, JP Magazine. Compare the advice here, http://bit.ly/Qrs4nJ and then the often referenced "Myth Busters" article here: http://bit.ly/4uveCG

I fully respect that many of the guys (and gals) on this forum have years, even decades of experience that I can never hope to match. Unfortunately I am one of those “I’ll believe it when I see it” kind of guys…so I am about to learn these lessons the hard way. That said, my goal is to improve performance of a daily street driven 1999 Jeep Sahara with automatic tranny and 4.0 and 3.55 gearing for the sole purpose of…well, just to have fun. No matter how this turns out I will have a good time doing it – and at the end of the day, that is why I even own a Jeep in the first place.

To keep things honest I started with a trip to J&R Racing in Greenville, SC to get my baseline dyno pulls. I purchased my Jeep brand new back in 99 and have performed all regular maintenance with quality components, synthetic oils, etc. and never abused it. As any Jeep owner knows, a Wrangler does require more repair than your average vehicle – and I will list what I have had to fix later.

Given the 181HP factory rating at the flywheel I was told to expect about 130HP at the rear wheels. I would love to hear comments from people with Jeep dyno experience if they believe this to be accurate.

I am about to start my first “phase” – ignition upgrades. I am starting here because this is a fairly easy area to make self-contained upgrades that do not entirely rely on complementary upgrades in other areas. These are also all upgrades that can easily be performed in a couple hours without any special tools. I will have another set of dyno pulls after this.

This phase includes:

MSD Ignition 6425 Digital 6AL Ignition with Rev Limiter ($230)

MSD 8884 Wire Harness for Above ($38)

MSD | 8228 | Dodge Late Model | Ignition Coil - Blaster - with 2 Pin Connector ($51)

ACCEL 300+ Ignition Adapter Harness ($25) – Required to attach MSD coil to stock wiring harness

Autolite APP985 Double Platinum Spark Plug ($4.50 each, but $1.50 each rebate)

ACCEL 120330 Distributor Cap ($15)

ACCEL 130330 Distributor Size Rotor ($7)

Magnecor 6595 Ignition Cable Set - 8.5mm ($76)

(About $460 total, almost everything was free shipping/no tax, and my time)

Everything is here, sitting in my garage and will be installed today. I will post a follow-up when I have another dyno pull. Due to my schedule that may be a couple weeks. I want to stick with facts since we can all convince ourselves we “feel” the difference when we look at how much we spent. Therefore I will not post a follow up until I have the next dyno run.

In any case, here are a couple pics.

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post #2 of 5 Old 08-12-2012, 09:17 AM
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Im curious

I am looking forward to what your results will be. I have the same year wrangler and also would like to boost its performance.
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post #3 of 5 Old 08-14-2012, 05:53 AM
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post #4 of 5 Old 09-16-2012, 05:25 PM
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Originally Posted by taztj View Post

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post #5 of 5 Old 09-16-2012, 05:51 PM
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Did you do a regear or axle swap? On phone so can't see full profile. The reason I ask is that I don't believe 3.55 was a stock gearing in 99 and is not a common setup to regear to if making changes.
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msd , sahara , upgrade

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