Information regarding engine performance upgrades...

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Ry' N Jen

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If I were to add:
A "Stage 2 performance chip, Shorty headers, Free flow (Read: better flowing) exhaust system,
modified throttle body and throttle body spacer, and a "cold air" intake.

Are these a worth while investment for the 3.7 liter V6 engine if installed
as a complete engine upgrade package?

How much of a horsepower/torque increase could you expect to gain from adding all these components?
10-15% horsepower?
10% more torque!
Are they worth while?
Would I notice a big improvement in throttle response and low end torque?
Re-gearing to lower differential gears would also be better. Correct?

I realize that the engine would require the use of premium unleaded fuel as well as a higher temperature thermostat.
 
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tjkj2002

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With a stock PCM................

You will feel it some for about 2 weeks then the added power will be zero as the PCM will adjust back to normal besides the trans shifting the JET chip provides.

With a modified PCM about 10% increase is what your going to get on average for those mods.
 
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rockymountain

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I wouldn't do it personally. I don't think you would ever need premium gas though. I think you only need premium gas if the compression ratio reaches a certain point which would be a great deal higher than stock.
 

tjkj2002

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I wouldn't do it personally. I don't think you would ever need premium gas though. I think you only need premium gas if the compression ratio reaches a certain point which would be a great deal higher than stock.
I have to use premium due to how much my KJ weighs,it's like towing 2000lbs around all the time. Anything less and it get's a ping.
 

incommando

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Octane is the rating of the fuel's ability to impinge knock. Compression isn't the only thing that it effects. It's biggest effect is on timing vs. knock/ping. Your aftermarket PCM wil try to advance your timing to make more power and, on modern engines, it does so until a sensor detects pinging. The higher the octane, the more timing it will allow before shutting it down due to knock/pinging. To use a chip that tries to increase power, usually through timing adjustments in part, and not to use at least the minimum ocatne rating suggested by the part's manufacturer is defeating the purpose of the mod.
 

jnaut

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If I were to add:
A "Stage 2 performance chip, Shorty headers, Free flow (Read: better flowing) exhaust system,
modified throttle body and throttle body spacer, and a "cold air" intake.

Are these a worth while investment for the 3.7 liter V6 engine if installed
as a complete engine upgrade package?

How much of a horsepower/torque increase could you expect to gain from adding all these components?
10-15% horsepower?
10% more torque!
Are they worth while?
Would I notice a big improvement in throttle response and low end torque?
Re-gearing to lower differential gears would also be better. Correct?

I realize that the engine would require the use of premium unleaded fuel as well as a higher temperature thermostat.

Skip the throttle body spacers. They're snake oil.
 

jnaut

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ive heard that over and over and over

Probably 'cause it's true.

One company actually went as far as to claim that the because the customer isn't noticing any performance increase proves that the device is working.

Which, in an ironic way, means that yes, they're telling the truth, it's doing exactly what you'd expect snake oil to do. :^o
 

tjkj2002

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Ya, but at the end of the day...
When you add up the prices of all these "Power add on's", is it worth it?
HP ain't cheap.........................

A average of $75-$100 per HP is the norm,for real/reliable HP gains.


Does not apply to diesels,those boost boxes for them just severely shorten there lives anyway.
 

KYLiberty

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Ya, but at the end of the day...
When you add up the prices of all these "Power add on's", is it worth it?

You can get some good power from the 3.7 to the ground, but it will cost big $$$. Only you can answer if it is worth it.

If you want to go down the power mod road, the first thing you need to do is take care of the computer. The only real option we have is a B&G flash. Mine is a custom aggressive flash. I also have a cold air hood feeding an AEM Brute Force intake into a Fastman throttle body into ported and polished heads. I have a custom built APS torque converter that is about as efficient as the manual, and has an increased torque multiplier and stall speed. I also have a Transgo reprogramming kit. The 4.10 gears definitely help off the line too. It exhales through custom installed JBA headers and a Borla dual outlet exhaust.

It is noticeably quicker than a stock KJ even with the heavy Silent Armors under it. However, I have a ton of money in it. Also, I have the 45RFE transmission instead of the 42RLE like yours. The transmission will be one of the limiting factors for you.
 

gijoe31484

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i want to see pictures of your setup KYLiberty!

You can get some good power from the 3.7 to the ground, but it will cost big $$$. Only you can answer if it is worth it.

If you want to go down the power mod road, the first thing you need to do is take care of the computer. The only real option we have is a B&G flash. Mine is a custom aggressive flash. I also have a cold air hood feeding an AEM Brute Force intake into a Fastman throttle body into ported and polished heads. I have a custom built APS torque converter that is about as efficient as the manual, and has an increased torque multiplier and stall speed. I also have a Transgo reprogramming kit. The 4.10 gears definitely help off the line too. It exhales through custom installed JBA headers and a Borla dual outlet exhaust.

It is noticeably quicker than a stock KJ even with the heavy Silent Armors under it. However, I have a ton of money in it. Also, I have the 45RFE transmission instead of the 42RLE like yours. The transmission will be one of the limiting factors for you.
 

gijoe31484

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I had a JetChip Stage 2 on my liberty when i bought it and the F$*%ing thing fried my throttle position sensor every time i drove in the rain. i went through about 10 of the the damn things before $1200 in labor searching for the electrical gremlins finally to figure out that the JETCHIP IS GARBAGE. my jeep RAN BETTER without it.
 

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