saad

Hi all,

I want to boost my engine power and make my JK more powerful and faster. And I'm not really sure what to do. Some people told me to change the exhaust system and the air filter!!!

I want to hear your opinion and if any one have done something similar like that or if any one has any suggestions???

08SaharaM6

An intake system-snorkel or CAI would work, cat-back exhaust, programmer, gears-not really an engine upgrade but performance upgrade none the less, if you upgrade tire size.

RedneckJeep

You can spend close to a grand between the two and not have anywhere near the bang for your buck you probably should. Everybody is trying to add power. Why not consider a universal dry shot nitrous system? 50-75 HP at the touch of a button would beat anything that's out there now except maybe a blower. In price though, the nitrous wins hands down.

08SaharaM6

nitrous is good and cheap but not a good idea if you want that power on a daily basis. I had mentioned a few lower priced mods, if budget isn't an issue and he doesn't plan on going threw deep water, I would tell him to get a supercharger for 4-5 grand. A hemi swap is in the tens of thousand's but if you got the cash, by all means do it. The power gains are minimal for bolt-ons but they all add up and if you can get 20-30 more h.p and 25-35 more ft. lbs. of torque why not. Any time you can get cold air into your engine it will benefit you, but forced induction is the best way to get power, unless they make a stroker kit for these 3.8's!

jkkat

Our Engines now
Engine - Number of Cylinders 6
Engine - HP Rated RPM 5000
Fuel Economy [mpg] - City [] 15
Fuel Economy [mpg] - Highway [] 19
Engine - Displacement - Cubic Inches 230.5
Engine - Displacement - Cubic Centimeters 3778
Engine - Standard Horsepower 202
Engine - Displacement - Bore [in] 3.78
Engine - Valvetrain - Number of Valves 12
Engine - Displacement - Stroke [in] 3.43
Fuel Economy [mpg] - Combined [] 16
Engine - Standard Torque 237
Engine - Configuration 3.8L V-6
Engine - Supercharged No
Engine - Compression Ratio ( :1) 9.6
Engine - Valvetrain - Configuration OHV
Engine - Torque Rated RPM 4000


I thaught that was called the 4.0 V-6 in the Nitro's

Engine - Number of Cylinders 6
Engine - HP Rated RPM 6000
Fuel Economy [mpg] - City [] 16
Fuel Economy [mpg] - Highway [] 21
Engine - Displacement - Cubic Inches 241.2
Engine - Displacement - Cubic Centimeters 3952
Engine - Standard Horsepower 260
Engine - Displacement - Bore [in] 3.78
Engine - Valvetrain - Number of Valves 24
Engine - Displacement - Stroke [in] 3.58
Fuel Economy [mpg] - Combined [] 18
Engine - Standard Torque 265
Engine - Configuration 4.0L V-6
Engine - Supercharged No
Engine - Compression Ratio ( :1) 10.2
Engine - Valvetrain - Configuration SOHC
Engine - Torque Rated RPM 4200

08SaharaM6

would you be ever so kind, to actually make an educated statement.

dpoelstra

First, remember that these engines seem to wake up after 3 or 5 thousand miles. A Cold Air Intake makes a big and worth while difference. Exhaust helps. i also installed the Jet Stage II chip and have now pulled it off as I could not tell any difference at all, and i suspect at costing me fuel mileage for no reason.

Other than that, I would install a hemi, which will take a long while to save up for so that is down the road.

Go with a CAI first. You will be happy.

adaycj

Read the quote, and look at the huge post of specs. See how the bore size (and a few other critical #s) are exactly the same. Now notice the stroke. The 4.0l Nitro engine is dimensionally a stroker as compared to the 3.8l. I have no idea if these engines are really the same at all, but it seems obvious to me that the one with nearly 60 more hp has a longer stroke and shares many other features.

As far as a statement, that post says volumes more than the allegedly "cold air" intake (CAI) and exhaust claims that continually come up. There seems to be no proof at all that these things can produce even a single digit increase in power. From what I can find 20 or 30 HP is a pipe dream.

08SaharaM6

Stroke as in aftermarket performance kit, not one stock vehicle to the next. As in getting more from the current engine. Line boring the cylinders, new crank, cam, pistons, rings, and so on.

adaycj

Agreed, stroking a motor is a major operation. It is in the same league as a supercharger because of the labor hours involved, even if there was a mostly bolt on kit available. It is just as out of reach as a Hemi for your average JK owner.