what should i get to get the most juice out of the 3.8? - JKowners.com : Jeep Wrangler JK Forum
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post #1 of 38 Old 04-15-2009, 04:23 PM Thread Starter
 
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what should i get to get the most juice out of the 3.8?

I'm looking to ad some performance to my stock JK engine. as far as im aware of with my extremly limited knowledge of wranglers. the only three ways to increase horsepower is to add
1. programmer/chip
2.exhaust
3. air intake.

my question is what makes and models of each of those 3 and you all like. and how much HP am i realistically going to add to my engine?
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post #2 of 38 Old 04-15-2009, 04:35 PM
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MBRP exhaust has a documented 9hp increase.

I would NOT do a CAI if your going to wheel it. Get a drop in airfilter replacement, you will get more power and better MPG

A chip or programmer is the way to add power. Even on the regular gas settings.
(Either superchip or hypertech) AEV is only for tires/ gears and NOT for power.

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post #3 of 38 Old 04-15-2009, 05:22 PM
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Why not do the CAI? There are a few good looking sealed ones like the Volant and the S&B. I understand the issues with swamping to engine, and if you plan to wheel in water, the get a snorkel. Some of us live where there just is not any water we can legally drive through and dust is the main concern.
The stock air box has a smaller hole than a stock 700cc V-twin. Yes, more availible air will do nothing with out more fuel, but with a CAI and the right mapping in the chip, you will get more power.
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post #4 of 38 Old 04-15-2009, 05:52 PM
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get the ripp supercharger

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post #5 of 38 Old 04-15-2009, 05:54 PM
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lol put it on a pallet and buy a hemi like we should have gotten from Jeep hehehe.
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post #6 of 38 Old 04-15-2009, 06:01 PM Thread Starter
 
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this is gonna sound dumb but does a snorkel replace the need for a CAI>?
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post #7 of 38 Old 04-15-2009, 06:22 PM
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all those are pretty much a waste. Any gains seen in most of these are above the 4k RPMs mark so unless you plan drive around at 4-5,000 RPMs spend your money on the gears for those 37's


O and don't get suckered into the "when I installed X exhaust I could feel the difference." Yeah when I was in highschool I swore my car was faster after an oil change and car wash too


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post #8 of 38 Old 04-15-2009, 06:26 PM
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Quote:
Originally Posted by Bigjerm View Post
all those are pretty much a waste. Any gains seen in most of these are above the 4k RPMs mark so unless you plan drive around at 4-5,000 RPMs spend your money on the gears for those 37's


O and don't get suckered into the "when I installed X exhaust I could feel the difference." Yeah when I was in highschool I swore my car was faster after an oil change and car wash too
Bingo...
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post #9 of 38 Old 04-15-2009, 06:50 PM
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Exhaust and a CAI do one thing, they make you sound faster!

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post #10 of 38 Old 04-15-2009, 06:53 PM
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Quote:
Originally Posted by SDMF View Post
Exhaust and a CAI do one thing, they make you sound faster!
plus one other thing... a new exhaust will get that giant beer barrel of a muffler out from under your rig and buy you a little more clearance!
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post #11 of 38 Old 04-15-2009, 07:43 PM
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Quote:
Originally Posted by DesertJK View Post
Why not do the CAI? There are a few good looking sealed ones like the Volant and the S&B. I understand the issues with swamping to engine, and if you plan to wheel in water, the get a snorkel. Some of us live where there just is not any water we can legally drive through and dust is the main concern.
The stock air box has a smaller hole than a stock 700cc V-twin. Yes, more availible air will do nothing with out more fuel, but with a CAI and the right mapping in the chip, you will get more power.
You are right, I thought I clarified wheeling in water... but alas..I didn't.

I live in Florida so everything is mud and water to me....LOL

The MBRP exhaust does document an increase in overall HP from 1800 RPM as I recall.

And I agree with gears being the first thing.. I missed that, even though I did this when I put my 37's on.

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post #12 of 38 Old 04-15-2009, 08:31 PM
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From what i hear, the 3.8 is pretty much at its peak performance right now, so most mods dont make much of an improvement save for a supercharger. Whereas if you could afford to swap a hemi into it, you're starting with a base to build on. Also, you can make your own CAI for your JK for about 70 bucks.
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post #13 of 38 Old 04-15-2009, 08:41 PM
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Freeing up the intake and exhaust does help,but not major HP gains.Definately helps with the mpg,at least in my case.You don't need to spend stupid money on exhaust mods either.A simple glass pak,flowmaster 40,magnaflow etc will do the same job as the arm and a leg mbrp system.It's just a catback,it ain't tuned like headers.If your really looking to run 37's,then you really need gears first.

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post #14 of 38 Old 04-15-2009, 10:31 PM Thread Starter
 
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sounds good i think i'll go with the consensus and buy gears so i can run 35"s or 37"s. and then maybe in the long run i'll screw around with engine preformance.
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post #15 of 38 Old 04-16-2009, 05:13 AM
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Well when I put my River Raider Snorkel on My MPG went up.. Plus I have a few other mods that gave me more on top of that. See my Sig



Changed to MPG!!!

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post #16 of 38 Old 04-16-2009, 05:37 AM
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Quote:
Originally Posted by mrsig View Post
Well when I put my River Raider Snorkel on My GPM went up.. Plus I have a few other mods that gave me more on top of that. See my Sig


GPM? You mean you're using Gallons Per Mile? It's not a Hummer!

From what I can tell you, MOST of the catbacks will give you a few horsepower UP TOP, and maybe a couple in the midrange. But this isn't a Honda, where revs=go. This is a JEEP, where torque is king. Backpressure (up to a point) shifts the power band to lower RPM's, adding torque. Our cars have fairly minimal backpressure (for an OEM setup), and reducing what little is to be had with larger diameter exhaust will kill what little backpressure is to be had, thus why the 3.8 with the bigger exhausts sounds like a Honda with a 5" fart can out the back- there's no backpressure!
This is why most people go with just a Flowmaster or other muffler- they reduce backpressure a MINIMAL amount, get rid of that monster OEM muffler, and add a deep sound because you still have backpressure.
Having built race and high-performance engines for years now, I can tell you- virgins brag about horsepower- pros brag about torque Unless you're turning your JK into a NASCAR "stocker," brag about how you improved your torque curve via engine tuning.

Best results I've seen from the 3.8 in terms of a solid on/off roader are from a Mopar/K&N drop-in, a muffler, and a Superchips/Hypertech programmer. Other than that, bump for a Hemi- Mark W.
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post #17 of 38 Old 04-16-2009, 07:09 AM
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Quote:
Originally Posted by thaduke2003 View Post
GPM? You mean you're using Gallons Per Mile? It's not a Hummer!

From what I can tell you, MOST of the catbacks will give you a few horsepower UP TOP, and maybe a couple in the midrange. But this isn't a Honda, where revs=go. This is a JEEP, where torque is king. Backpressure (up to a point) shifts the power band to lower RPM's, adding torque. Our cars have fairly minimal backpressure (for an OEM setup), and reducing what little is to be had with larger diameter exhaust will kill what little backpressure is to be had, thus why the 3.8 with the bigger exhausts sounds like a Honda with a 5" fart can out the back- there's no backpressure!
This is why most people go with just a Flowmaster or other muffler- they reduce backpressure a MINIMAL amount, get rid of that monster OEM muffler, and add a deep sound because you still have backpressure.
Having built race and high-performance engines for years now, I can tell you- virgins brag about horsepower- pros brag about torque Unless you're turning your JK into a NASCAR "stocker," brag about how you improved your torque curve via engine tuning.

Best results I've seen from the 3.8 in terms of a solid on/off roader are from a Mopar/K&N drop-in, a muffler, and a Superchips/Hypertech programmer. Other than that, bump for a Hemi- Mark W.
I totally agree,especially about the exhaust hype.The outfits trying to sell you 4 or 500 dollar exhaust systems for "big hp gains are full of crap.Even if they dyno proved it,it's done at top rpms,which you'll never see.Keep It Simple and enjoy

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post #18 of 38 Old 04-16-2009, 07:23 AM
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Yeah Hemi.
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post #19 of 38 Old 04-16-2009, 07:38 AM
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Blower or Hemi...

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post #20 of 38 Old 04-16-2009, 09:14 AM
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^ I'm not sold on the blower for a couple reasons.
1. Is heat. The JK underhood area gets pretty darn toasty as it is due to a relatively lean-burning enine. While the chip included with the kit would remedy some of the lean-burn issues, the blower itself creates a lot of heat, as does the increased boosted compression (not to be confused with compression ratio- this is that, plus the pressure of the forced air).
2. Is cost. For not much more (relatively), you get a garuanteed, known entity. The 5.7 Hemi is dead-reliable, stock (assuming you leave it that way), and thus built in a way that Chrysler is comfortable giving it a LIFETIME warranty. The supercharger's warranty only covers the kit itself, and says nothing about how well the engine itself will hold up. While Chrysler obviously won't warranty the Hemi you put in your JK, it is garuanteed to last for years as long as you don't mess with it too much.
3. A report I read from Mopar a few years ago about their efforts to make a turbo 3.3/3.8 setup. I remember distinctly the phrase "came apart under even mild boost." Now, the newer 3.8 is somewhat stouter than the 3.3, BUT it is still the same basic architecture. I know that to an engine builder/engineer, "mild" boost is under 14.7 PSI of boost. I can't remember seeing what the blower kit pushes, but it is likely 5-9 PSI on most setups. I know that supercharger boost is quite different from turbo boost, but the problem lay in the rods, which take up a lot of the pressure of combustion, which is increased massively under ANY kind of boost.
While this is not THAT much, it is enough for me to question longevity. I simply won't be able to reccommend something as (relatively) untested as the supercharger kits until I see 100k mile+ individual vehicles with no major problems becoming the norm.

I am in NO way associated with RIPP, and have nothing but the utmost respect for anyone who brings a new and (by what I've seen and heard) high-quality product to the market. As a professional, I simply tend to stick to known quantities on street vehicles. On race cars, I run prototype and one-off pieces all the time, but for a daily driver, I just can't reccommend aftermarket super- or turbocharger kits, especially relatively new ones.
No hard feelings fellas- there's always beer in my garage for you guys at RIPP Mark W.

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post #21 of 38 Old 04-16-2009, 10:04 AM
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I've encouraged Ross @ RIPP to get on here, so hopefully you'll see him on here soon to support as a vendor and cure some of what I believe to be common misconceptions about the supercharger on the 3.8L

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post #22 of 38 Old 04-16-2009, 10:27 AM
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What I said isn't based on any misconception. I know NOTHING about the specifics of the kit. What I DO know is supercharger systems in general, and the inherent characteristics of boost, superchargers, and engines. I also know what I read in a Mopar engineering report on boosting the 3.8 V6. I'll try and find it, but I read it at a Chrysler dealership years ago, so no promises.
My comments were MY personal feelings and thoughts. I put my name behind every vehicle I've ever built- I etch my name into the intake manifold or valve cover of every engine I've ever built or modified enough to earn my garuantee.
I know there are countless people running boost in daily drivers on 3.8L and other less-than-stellar perfoming engines. That's their choice. My feeling on the subject remains the same- it's simply not worth trying to get big-number performance out of non-performance engines. Stick to the basics, or swap it. The less you mess with, the less that'll go wrong. Mark W.
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post #23 of 38 Old 04-16-2009, 02:12 PM
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Reliability is a great subject because every single person needs their builds irrefutably safe in every aspect.

In 2007 We began testing our JK 3.8L equipped with a RIPP supercharger running 10psi for 40,000 miles before releasing the kit to the market. Before selling we pulled the motor, checked internals only to find all cylinder walls, pistons, rings, rods bearings, and cylinder head to be in PERFECT condition and with-in spec. That same motor was reassembled with its original components and driven another 15k miles before recently driving across the country to Utah (for the EJS in MOAB) 2,800 miles straight. Mind you the owner behind the wheel (RIPP engineer) has a right foot made of lead. There is video of him traveling up hill @ 5,000 RPM's boosting for 20 min straight ( it's quite amusing). We hit MOAB for a week for EJS.. rock climbing, and racing it around all week. Turned around and drove her home another 2800 miles with out braking a sweat.

We have an easy 60,000 miles logged on just one of our JK's. On top of real world testing we also spent countless hours on our AWD Dyno logging air/fuel ratios, exhaust gas temps, knock counts, ignition and injection times. With all the data gathered we have developed a "Bolt-on" supercharger that not only installs in 6-8 hours and adds a 100HP (starting at 2500rpm's) but is also proven to be as reliable as your stock motor.
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post #24 of 38 Old 04-16-2009, 03:28 PM
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Heh, looks like you were already here!

I no longer work with Warrior. I am now working with The FIRM.
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post #25 of 38 Old 04-17-2009, 06:19 AM
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RIPPMODS,
Can you post any engine pics of how a snorkel would mount up to your system? I noticed there is one shot where the silver Jeep looks like it has the River Raider snorkel.

Never mind, found it on your site:
http://www.rippmods.com/v/vspfiles/p...k-snrkab-6.jpg

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