Does anyone run a tune on their TJ?

Brianj5600 said:
The static compression ratio is 8.7 and dynamic compression ratio is 7.47. Would a 4.0 tuned and modified like posted above benefit much from octane higher than 87?
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The compression doesn't require more octane, but the tune may if you pushed the ignition timing up enough. I think a good performance tune in a 4.0 would be more timing and more fuel at WOT. The ones I have run on the dyno stock all seem to be a little lean and reasonably conservative on the timing.
 
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Jezza said:
The compression doesn't require more octane, but the tune may if you pushed the ignition timing up enough. I think a good performance tune in a 4.0 would be more timing and more fuel at WOT. The ones I have run on the dyno stock all seem to be a little lean and reasonably conservative on the timing.
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Educate me on this, Jezza. It’s likely an oversimplified view, but I’ve always thought it was compression, or ultimate cylinder pressure as in the case with boost, that drove the need for higher octane which allows throwing more timing at it. Is that not the case?
 
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NashvilleTJ said:
Educate me on this, Jezza. It’s likely an oversimplified view, but I’ve always thought it was compression, or ultimate cylinder pressure as in the case with boost, that drove the need for higher octane which allows throwing more timing at it. Is that not the case?
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Even at 8.5 compression the factory leaves some timing out of it to keep it safe. You can put some timing into it and make more power, but I would run higher octane at that point to keep it safe. Hope that helps I'm not the best at explaining this stuff.
 
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Jezza said:
Even at 8.5 compression the factory leaves some timing out of it to keep it safe. You can put some timing into it and make more power, but I would run higher octane at that point to keep it safe. Hope that helps I'm not the best at explaining this stuff.
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I believe I remember Ryan, @Flyin' Ryan Performance , discussing this in more detail in his thread.
 
Fishtaco said:
I am expecting to Fuck off the stupid pre cats and o2 sensors on my 06 eventually! having a 6 cylinder gas guzzling "Brick" with emission controls that are just "The Emperors New Cloths" Plus we dont Smog or MOT in Australia ( for our UK brethren) :) But I do want to ask about exhaust smell for those that have deleted their cats.
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I have a header, no cats, edge trail jammer programmer kit which came with cold air intake and bigger throttle body. I have constant issues with check engine lights and rich running conditions. I put the spark plug extenders in all 4 O2 sensors and it helped for a little while. I think I’m gonna try a wrangler fix PCM and get them to tune out the O2 sensors. Sounds great, helped with power at first then I think the pcm has issues with the programmer which keep making changes. Helped with fuel mileage for sure by a couple mpg’s.
 
Big Poppa Stew said:
I have a header, no cats, edge trail jammer programmer kit which came with cold air intake and bigger throttle body. I have constant issues with check engine lights and rich running conditions. I put the spark plug extenders in all 4 O2 sensors and it helped for a little while. I think I’m gonna try a wrangler fix PCM and get them to tune out the O2 sensors. Sounds great, helped with power at first then I think the pcm has issues with the programmer which keep making changes. Helped with fuel mileage for sure by a couple mpg’s.
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According to Ryan, their programs will NOT defeat emissions control devices. You'll have to use the HPTuners Interface to do that some how, I'm not sure how it's done. I believe @Chris was the last one I remember discussing how to do that.
 
Depending on the HP Tuners software version you may not be able to remove the sensor. I was at first and now after some updates the feature was removed.
 
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Fishtaco said:
I am expecting to Fuck off the stupid pre cats and o2 sensors on my 06 eventually! having a 6 cylinder gas guzzling "Brick" with emission controls that are just "The Emperors New Cloths" Plus we dont Smog or MOT in Australia ( for our UK brethren) :) But I do want to ask about exhaust smell for those that have deleted their cats.
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Pre-cats is something I wouldn't mess with. Clesed loop is probably the part they got right.
 
Grover728 said:
Depending on the HP Tuners software version you may not be able to remove the sensor. I was at first and now after some updates the feature was removed.
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Let me guess, there's no way to uninstall the latest update and go back to the previous software version...
 
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