Can you stack chips on a 97 4.0 jeep wrangler I already have a hyoertech max energy programmer and I wanted to know if i could use another chip alos ? like a Jet stage two chip?? anyone know? thanks  

You've got to be careful to pick products that don't overlap. That is to say, don't grab a chip that modifies the timing if you've already got a chip that modifies the timing.

In a nutshell, most gas engine programmers (especially for Jeep vehicles) simply modify the spark timing advance curves and maybe adjust the MAP/TPS position readings or injector pulse durations to boost more fuel to the engine. Performance-wise, there's not much else they can do. There are also other options like tranny rpm shift points, rev limit mods, speedo adjustments, etc., but those really won't get you more horsepower - they're driveability options.

Your Hypertech mainly modifies the timing. I'm pretty sure it does little-to-nothing to increase the fuel delivery. Although it's not a "chip", you may see benefits from running an adjustable MAP sensor to increase the fuel delivery. Check Turbo City, www.turbocity.com for an adjustable MAP sensor that you can wire in series with your current MAP. It's basically a fooler box that makes the throttle-body-mounted MAP think it's reading a different voltage than it is, so it delivers more fuel at less throttle input.

Also, check Edge for its Trail Jammer electronic box, as it only modifies the fuel delivery and leaves the ignition timing alone.  

...more fuel with less throttle input...

Sounds like a carburetor. And then change the computer's ability to sense the rich condition so it doesn't lean it out again.

Boy, the good'ol days, when everything was good. We only had one wire to the ignition and a double pumper so we could dump in more fuel.

I can't beleive you're encouraging him.

Give me $400 and I'll tell you your fortune. I'll use words and state statistics that make it impossible for you to ever know if I was right.

The best ad is Banks. "More Air + Less Backpressure = More Power". What does that even mean. More air = More Power. Ya. Less Backpressure = More Air. Ya.

Is Backpressure really an enemy. Backpressure and cam profile work together. Reducing backpressure without regard to cam profile actually causes over scavenging, reduced cylinder pressure, and higher exhaust gas temperatures.

The EGT rises because some of the intake charge is being sucked out because of the over scavenging, and is being burned in the cats. That leaves less fresh charge and reduced cylinder pressure which equals less power. Why doesn't Banks recommend a cam change? I think we know why.

Don't be so quick to think that the engineers who designed, built and TESTED the engine, drink their lunch.  

If you have forced induction no backpressure is needed, there for get a turbo or blower and dont worry about it.  

That's right. Exhaust changes coupled with other changes makes sense. Building power in the upper RPM ranges, that makes sense.

All the advertising for chips, air filters and exhaust appear to promise all kinds of good stuff. But, they really don't promise anything.

33% more air flow. But the test was done on a bench. How does that apply to your engine.

What happened to 1/4 mile test times, or even better 0-60mph tests, to prove your product? Better believe, if it looked good on the advertising pages they'd use it. Suspiciously missing.  

In Hypertech's advertising for the Max Energy programmer for a 2004 Wrangler, "a 14hp gain". But when you look at the test data, that's just one RPM that made the biggest difference. And it is 5170rpm. Wow, I didn't even know my motor would do 5100rpm.

But the peak HP with the chip 157, and peak HP without the chip, 153.

Now, the Max Energy does some cool things, but those cool things are not what people are buying it for.

$400 will buy a lot of beer if you want to just feel better.

And this guy wants another chip on top. Boy, I'd better hedge my stock portfolio from GM to Hypertech.  

theres a 1/4 mile in the steal j articles online if I remember right, he put the trailjammer on it.

I've installed a few stage 2 jet chips, they make a seat of the pants difference even in a tj with 33's and 3.73 gears. on my o3 it improved the power by got under 10 mpg's....  

Truth in advertising:

Rock-It, maker of an adjustable EFI MAP sensor for Jeeps states

"...can not be used in conjunction with performance chips." "The adjusable MAP sensor will eliminate surging and bucking when power-gaining modifications are made."

What it does not say. The adjustable MAP sensor is a power-gaining modification.


XDI Air Intake System for Jeep vehicles states

"... is able to improve horsepower and torque in applications requiring greater airflow than the factory intake is capable of."

What it does not say. The intake system changes the engine's airflow requirements.


No track testing data found for "Steal-J". The first article plainly states:

"While we didn't have a chance to dyno the system, based on our seat-of-the-pants estimates we have no reason to doubt Edge's power gain claims of 20 hp and 26 lb-ft."

In the article "10 Proven Power Plays", there are dyno tests for Steal-J, but again no track data. Dyno test shows an increase of 15hp.

What is interesting is the financially invested, seat of the pants opinion of 20hp gains, but when actually tested went to 15hp. The other thing that is missing is the RPM range that produced this 15hp gain.

When studying the hp increases of other chips, the gains are closer to 3-5hp increases across the usable RPM range and peak totals of 5hp, not the misleading 15hp differential at 5200 rpm.

Now, I'm not saying there is no increase. Just at what expense. Seems like $400-$1000 is a lot for 3-5hp. And this is not even taking into account the negative affects of the programming changes. The effects on drivability and emissions are not important until...

"... I have changed my cats, my o2 sensor, my plugs, my cap and I'm still getting mis-fire...and I have to pass emissions so I can get to work... PLEASE HELP NOW".