JK Horsepower

[Muzwrath]

Hello, Anyone know how much Horsepower you can sqeeze out of the anemic 3.8 engine? I am really considering buying one but I test drove one and my god it lacks power.

Thanks! graemlins/49.gif

[b1pig]

how much you can "squeeze" out of it is pretty much up to what you want or intend to do with it.

there are a few companies that are distributing supercharger kits for the JK. some are posting 75-100hp increases on 5 psi or less on pump gas. (at least one on 87 cotane)

i can attest that there is a mild increase in driveability as the miles increase. I have 7,000 miles on my Rubicon. I also have a K&N intake kit. (no exh mods). it runs pretty well. in wet roads, with the ESP "off", it will constantly spin the tires. this is with the 32" BFGs, 4.10s and auto tranny on my rubi.

you should conpare your JKs that you drive. there are two different gear ratios. the 3.24 (or 3.21) gear ratio works better with the 6spd. the 4.10 works better with the auto.... but also works really well with the 6spd.

the first one that the wife and I drove was a X Unlimited with 6spd and 3.2x gears. My rubi has the auto with 4.10 and 32s. if you get a sahara, do what you can to get the 4.10s. the weight of the wheels and the overall tire diameter tax the 3.8...

once you add a couple power mods, the 3.8 shows its potential. remember that the 3.5l v-6 is the engine of choice for the v-6 police package Charger. while barely related, you can get the idea. (a v-6 Charger police pkg still outruns the 4.6 v-8 Ford CVPI) i have only a K&N at this point on my JK.. and it screams. stock, i think my modded ZJ would keep up with it.... and probably leave it at the line.. but it runs out of breath at about 65mph. alot of weight. now, i cant say that. the JK is really starting to open up.

[Eirene]

b1pig,

Quick question for ya. Once you added the K&N, how did your gas milage do? I had on the Dodge I use to own and it dropped the mpg, bad! So I'm a tad hesitant to put it on my JK, espeically with how awful gas prices are up here.

[b1pig]

in all honesty, if driven at a reasonable speed, there was an apparent improvement of one or two mpg... it varies. you can NOT rely on the computer in the JK to figure the fuel burn. it was programmed by a crack-smokin programmer. (fuel mileage should only be firgured for miles traveled... not by the tankful.)

I tend to um... have a heavy foot. :D

honestly, i think i'm averaging around 17mpg.... give or take. i think you said you got a Rubicon, right? Mine is a Rubi with auto tranny. a 6spd will obviously be better. the computer does some stupid crap on the tranny too.

[Eirene]

Yea, mine's the same -Rubi w/auto -purdy dark red. :D

Ever seen New England drivers? If you don't have a lead foot you are going to get run over, lol.

I only use the computer to try to remind me to keep my lead foot to a minimum ;) but I rely on how many miles I'm getting per tank.

Thanks!

[b1pig]

actually, we were in PA and New York City after Thanksgiving... so yea. i see you yous guys drive. :D

[csbobo]

Which K&N did you install?

[b1pig]

63 series.
http://www.quadratec.com/products/17127_100.htm

[Jeeper3]

Hi flowmaster,aem system,throttlebody, engine still sucks next to the 4.0, still love my jk.

[b1pig]

Originally posted by Jeeper3:
engine still sucks next to the 4.0, still love my jk. couldnt agree more.

welcome. :cool: