performance chip woes
- Thread starter my07kj
- Start date
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They list their chip as being for the 2002-2011 even though there are completely different ECU's within those years. They also list an extra 60 hp and 60 torque, combined with better fuel milage.:happy175:
IT WILL NOT WORK!!!
IT WILL NOT WORK!!!
waywardtravel
Full Access Member
It's pretty hard finding any advice on any performance chip for the KJ. I think I've read of only one guy who did it but he built his engines many times with serious mod's.
As for the one you mentioned if they claim 60HP and 60 LB/FT I would stay away myself. Unless that kit included a cam, exhaust, and a cold air intake, and maybe a throttle body.
As for the one you mentioned if they claim 60HP and 60 LB/FT I would stay away myself. Unless that kit included a cam, exhaust, and a cold air intake, and maybe a throttle body.
JeepINgeek
Silver Supporter
typically chrysler's ECUs override aftermarket insta chips... like the jet...
Kind of funny. You're talking about me.
If you want programming that actually works for the 3.7, talk to B&G. Otherwise, don't waste your time and money. Oh, and no programming will make anywhere near a 60 HP difference on the 3.7.
JeepINgeek
Silver Supporter
how much did the B&G job cost? is it still like $300?
waywardtravel
Full Access Member
Kyliberty thanks for your write up I read it many times and still don't think My KJ will ever have any real engine performance gains. You seem too have too go over the top for minimal gains. Am I correct to think I could gain roughly 12-22H.P. after B&G, Cat back, and K@N cold air intake? Now I have to bring that back down about 5H.P. to not ingest water in the intake while offroad,(return to stock airbox)
twack
Full Access Member
what does horsepower have to do with sucking in water haha
If you're looking for more power and plan to off road, you really should be looking at gears. If you go to 245/75R16's, some 4.10's will make a world of difference. If you go bigger, you may want to look at the JBA steel front diff with some 4.56's or even taller gears. You'll lose some top end, but down low is where it really matters in a Jeep.
waywardtravel
Full Access Member
I am definitely re-gearing.(I'm part of the choir, have at least 10 R&P's on my shop wall, even Dana 30 4.10 but they won't fit the 30A). From what I've read so far I'm pretty sure the tallest you can go with the factory 30A is 4.11. This is my daily driver and I have another Jeep for off road trips. I just am used to having more power than the KJ has and will part with some money to give it more torque in the lower RPM's if it makes sense. It will see off road but not to extreme. I would be very happy with 4.56's but I just really didn't plan on putting that much this fast into this KJ. Thanks again for the advice.
Depends on how much $ you want to spend. Definitely do the gears and get the B&G flash. A good drop in air filter is all you need for the intake, but you can go with a throttle body from FastMan to help response a little. Since you have the 42RLE, you can talk to APS and get an upgraded torque converter and a shift correction kit, but they won't make the big difference they do with the 45RFE. A decent cat back can help a little too. You can try and get some headers from JBA, but it may take months and they may have to be custom installed.
03kjlmtd
New Member
I've had the jet performance chip installed for the past year. It makes a big difference in throttle response = better acceleration. No problems or complaints, just a matter of whether or not about a half a second to a second off your 0-60 time is worth $200-$300 to you. Premium fuel is also recommended with it.
03kjlmtd
New Member
Also, the ecu did not override the chip. When the chip is taken out the throttle response is still not nearly as responsive, just the same as when it was first installed. Don't expect huge horsepower gains from any instant chip.
Just remember, if you're running a jet stage 1, don't do with and without dyno runs or quarter mile runs. Only go by seat of the pants. I've never tested the stage 2, but have heard that it does make a small positive difference instead of the negative difference the stage 1 made when I tested it.
twack
Full Access Member
I have a stage 2 and it does seem to make a difference, nothing crazy but noticable
You do know that taking a second off the Liberty's 0-60 would take about a 35 hp increase don't you? $200-$300, sorry, try $2000-$3000. :smokin:
What I ran into when testing the stage 1 is it would richen up the fuel mix and increase the timing. Below about 3000 RPM, it would give a slight increase, but then the torque management would kick in and it would fall on it's face even worse than the stock ECU and drop about 5 RWHP. Even though it felt slightly peppier off the line, it was actually a slower 0-60 by a fraction of a second.
The version of the stage 1 may be better with the newer KJ's, but I don't have one of them, and like I've said, I haven't tested the stage 2. I must admit that I am a little biased against jet following my experience with them. When I contacted them about the poor performance of the stage 1, they ended up offering to make a custom chip for another $400-$450 (can't remember exact price but I'm sure you could find it by searching back through forums 6-7 years). They also said they wouldn't need my dyno numbers or anything to be able to make it. I finally got them to admit to me that not only had they never tested it on a KJ with a 3.7, but they had never even tested it on a 3.7 in anything.
There is a guy on the Dodge forums by the name of hemifever. He has custom tuned a buttload of 4.7 and hemi Dodges. I think it was Bionic Dodge (I am currently underway/deployed so I don't have the bandwidth to try and find it), but he tuned a 3.7 Ram then a 3.7 Liberty (04 I think) with an SCT handheld tuner. He didn't have hard numbers available, but he said it was definitely noticeable on a stock configuration. Might be worth looking into if you plan some engine upgrades.
03kjlmtd
New Member
The stage 2 chip, along with a CAI and performance muffler took about a second off my 0-60*
I used to have vids on youtube doing consistent 7.5 to 8 sec 0-60's. Not that I think 0-60 is relevant in a 4x4, just having fun.
I used to have vids on youtube doing consistent 7.5 to 8 sec 0-60's. Not that I think 0-60 is relevant in a 4x4, just having fun.
