Stage-2 Jet chip...

[BillR]

I've heard all the talk, pros and cons. I got a good deal on it, so I thought I'd see for myself. I already have a bored TB, air tube w/K&N, and Magnaflow exhaust. I installed the chip and the 180 t-stat tonight and went for a drive. It DOES make a difference in all speeds. Off the line was better, meaning torque has increased. Passing gear feels ALMOST like my wife's 5.2L ZJ. (not quite) AND, I'm still running regular gas. I'll put a tank of premium in when this one's almost out.
It's hard to tell too much from a 15 minute drive, but so far I'm impressed. :thumbup: Jet states 14-17 hp increase in their ads, and I'm thinking it's probably not TOO far off. There's a definite difference!
We'll see what happens over time after the ECM "learns" what it's supposed to do...

 

[imma honky]

I'm wondering if you will only see those gains if you have (like you already have done)other engine mods. Just curious, how good was the deal?

 

[BillR]

The Stage-2 is designed to work with a slightly modded engine. The Stage 1 is for stock set-ups.
I got the PowerPak for $220. (chip, t-stat, and ProFlo air filter for a stock air box)
Anyone need an air filter...?

 

[truckerdirt]

watch out for computer problems now. i've seen a lot of reports of guys running jet chips then getting allkinds of check engine light codes, or malfunctions shortl after installing them.

 

[XJack]

I heard the same horror stories with engine codes and cruise not working either.

I ran my Stage 2 for 10K miles without any problems, except gas prices going through the roof.

Anyone want one for $125?

 

[tcm glx]

Qjack, I am interested......shoot me a Private so we can take this offline!

 

[xjhm]

does anyone make an adjustable fuel pressure regulator for the xj's?

if so you can accomplish basically the same increase in power, by bumping the fuel pressure up a few pounds and giving it a few degrees more timing...i actually saw better runs at the strip in my mustang, by playing with the pressure and timing and removing the chip...
3/10's with the chip over stock and 6/10 via the timing, and honestly, i never felt any difference in power...
but if you don't know what you are doing, as far as setting the timing for power, then the chip may be the best route...but not the cheapest...

and as far as the high octane fuel goes, you don't need it unless you are experiencing detonation.
however certain fuel brands do have additives to make the fuel burn more completely... ie; sunoco has oxygenators added to make a more complete/efficient burn within the cylinder.

 

[btl_fed_xj]

I ran one in my XJ and could pull off a 6.5 0-60 without too much trouble. I never had any trouble with it. As far as I know no one makes and adjustable fuel pressure regulator for the XJ. I custom fit one in my XJ but I sold it 2 weeks ago so I don't know who made it. It's definitely a nice way to get those few extra hp out of your truck.

I am working on a 1998 Yukon now, it'll never be as fast as the XJ but it's putting out 300 hp after the mods that I have done to it. It's definitely an additiction!!!!

 

[Dr. Dyno]

Hesco make an adjustable fuel pressure regulator for the 4.0 but it costs close to $200. If your engine's running slightly lean, another far cheaper alternative is to install a MAP adjuster and increase the voltage to the MAP sensor above the stock 5.0v. The injectors will be held open for longer so the A/F mixture can be enriched. Turbo City sell a MAP adjuster for close to $100 but why pay so much when you can make your own? Read my article on how to build a MAP adjuster for less than $10:

http://www.angelfire.com/my/fan/MAP_adjuster.html

You can also use the MAP adjuster to lean out the A/F mixture if you've installed oversize injectors and the engine's running too rich.

 

[DeftwillP]

I heard the same horror stories with engine codes and cruise not working either.

I ran my Stage 2 for 10K miles without any problems, except gas prices going through the roof.

Anyone want one for $125?

I was under the impression that you could run 87 octane with either chip?

 

[DeftwillP]

bttt

 

[Ramsey]

it suggest 93 for it to perform best

 

[Dr. Dyno]

I've had the JET Stage 2 in my 4.0 XJ for the last 7 years and not had any problems with it. Then again, I wasn't blown away by any performance gain either. My homebrew MAP adjuster was a far better mod and it cost me only $9 compared with $300 for the chip.

 

[XJack]

I was under the impression that you could run 87 octane with either chip?

Not on the Stage 2 - Jet suggests 93.

I was able to run both 89 and 93 with ignition, throttle body, intake, exhaust, and tip-top engine cooling on an already rich-running 4.0L.

Engine never pinged whatsoever, but it was easy to tell that the 93 ran a hair better. Steadier idle and better partial and full throttle response with the Premium Unleaded.

 

[Dr. Dyno]

Yeah, JET recommend 93 octane with the stage 2 chip but over here we have 91 octane with MTBE and my 4.0 runs great. It doesn't ping either despite having raised the CR to 9.1:1 with a thinner head gasket and 0.010" milled from the head.

 

[fdsa487]

I have the Stage II Jet Chip and i love it. Made a world of difference. I also have a K&N FIPK, Header and Flowmaster Cat-Back.

 

[XJ_ranger]

I have the Stage II Jet Chip and i love it. Made a world of difference. I also have a K&N FIPK, Header and Flowmaster Cat-Back.

someone searched way back to give their $.02

 

[fdsa487]

someone searched way back to give their $.02

I always gotta get my $.02 in there.

 

[Dr. Dyno]

I'm still using the JET Stage 2 and MAP adjuster on my stroker with no adverse effects. Engine runs great.

 

[fdsa487]

I'm still using the JET Stage 2 and MAP adjuster on my stroker with no adverse effects. Engine runs great.

Mine runs great to. Excellent actually but its not a stroker and it only has 70K miles on it.:us: