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Posted · Report post

I have a 1996 Jeep Cherokee 1996 stroker six with these specification:

 

- High compression pistons

- CompCams camshaft #68-239-4 with lifters, valve springs, retainers, etc.

- Three-into-one header

 

Currently, I have a Hypertech program with a Unichip rev limiter module on the way.  I want the most powerful computer and am considering these options:

 

Superchips - SCT Computer - Jet Performance Stage 2 module

 

Which is the strongest module?

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Posted · Report post

jeepstroker…Welcome to the forums!  We value your participation and questions...

 

The Hypertech "Max Energy Programmer" works great for me on our stock 4.0L ’99 XJ Cherokee.  (See my comments at the article on this Hypertech installation:  http://www.4wdmechanix.com/Hypertech-Max-Energy-Power-Programmers-for-Jeep-4.0L-and-Dodge-Cummins.html.)  I use the low octane setting.  No ping, works very well with stock compression ratio. 

 

On your engine with higher compression, you may want to run the Max Energy's high octane setting but this will demand use of high octane fuel.  I am happy with the low octane fuel setting and the Hypertech “Max Energy Programmer” computer programmer.  I have not used any of the other brand "programs" you mention and do not recommended running multiple programs.

 

One thing to consider with the "strongest" computer programming is whether you plan to drive the Jeep XJ Cherokee on the street and highway.  For drivability, you want a user and engine friendly software program that is the best compromise for performance, available fuel octane, and economy.  In my experience, Hypertech did it's homework on this program.  The others mentioned may very well provide a performance edge, but without driving and experiencing the use of these other "programs", I must limit my response.

 

Other members may want to jump into this discussion with their experiences around the Super Chips, SCT and Jet Performance programs.  You might also call or Email the tech line for these manufacturers and share your Jeep stroker engine build-up details.  They should know how compatible their software would be with your modifications.  Your engine is octane sensitive with the higher compression, and there is no knock sensor to signal the need for retarding the spark timing.

 

Moses

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Posted · Report post

After I run the engine, using petroleum fuel station (93 octane) fuel, I heard a sound.  (Sounded like valve springs, maybe?  Then I tested fuel Q16...Engine works excellently on fuel Q16.  What is the problem?  Is this octane related?

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Posted · Report post

This sounds like detonation or “ping”.  Detonation is the result of high compression and running lower octane fuel.  If higher octane fuel remedied the problem, you may be able to run lower octane fuel by retarding the ignition timing. 

 

Spark timing changes are not done by moving the distributor on a Jeep 4.0L type ignition system.  Spark curve and base timing changes are made by reprogramming the PCM with less spark advance.  There is a provision (usually for up to 5-degrees spark retard) that can be re-programmed into the stock engine PCM/computer.  This is done with either a factory DRB-III scan tool or an aftermarket scan tool that has the ability to correct base spark timing errors.

 

Again, this is why I'm conservative about aftermarket programmers, as they usually target spark timing curves and advance the timing.  You may get more power from one or the other programmer; however, you may also get severe and damaging detonation.  This is why the Max Energy is a program that works for me:  The stock compression engine will not detonate (ping) on 87-octane fuel.  If I wanted to run 91-octane or higher, I could use the Max Energy high octane programming that came with the package.  In your case, the engine needs higher octane fuel already due to the higher compression ratio.

 

Moses

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