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Discussion Starter #1
Upgraded to 35s Tuesday, knowing my auto Rubi would be a dog with them. Drove around for a day, and yeah, it was a dog.

Did the Superchips tire size change the following day to fix the speedometer. Also did the "87 Performance Tune".

Holy crap, what a difference it made! It accelerates so much better than it did with stock tires, and when I'm just maintaining speed, the RPMs seem a fair amount lower. :bounce:

Is there some catch I'm missing? I mean, I really really enjoy driving my JK so much more now. There's got to be some trade-off for this??? I know I can potentially void my engine warranty with the dealer, but is there any physical damage this "Tune" could be causing? I can't imagine why Chrysler wouldn't send all JKs out the door tuned like this!
 

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AFAIK, there's no catch. The first thing the tuner does is eliminate a lot of the sluggishness in the gas pedal. It also changes the transmission shift points so an auto trans will downshift quicker to get you into the engine's peak power band. Some improvements in the fuel/air mappings gives a little more hp. If you like the 87 tune, throw in a tankful of premium-grade gas and run the 93 Performance tune; you'll be hard pressed to go back to regular.

As for the lower RPM, that's simply a matter of physics. Larger tires cover more ground per revolution. So at any given speed, larger tires require less RPM than smaller tires. The other side of that equation is that, for a given weight, more horsepower is required to turn the larger tires.
 

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I have done a lot of research the last few years on engine tuning. The generally available consumer tuning does not harm the engine. The main reason you notice a difference is the change in shift points. The second reason is that the tuning company has put the engine through a lot of mapping cycles to get the best performance for differing tire sizes and power bands. The stock tune is for the smaller tires and for a baseline performance. Manufacturers must stay within certain guidlines for emissions and mpg. I have often wondered why manufactures do not harness all that it can, but the basic cars do not. The higher end sports cars are generally tuned better, but still can be improved with add-on parts that the computer tune makes use of.
 

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Dont swet the warranty, your tuner has the stock factory tune stored in it if you have to go in to the steelership for work inatall the stock tune they wont know what your up to( just take your tuner out of the glove box) them guys are sneekey the root around
 

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As for the lower RPM, that's simply a matter of physics. Larger tires cover more ground per revolution. So at any given speed, larger tires require less RPM than smaller tires. The other side of that equation is that, for a given weight, more horsepower is required to turn the larger tires.
He's talking about after the tune, not after the tire change, right brat? I've heard this before Greenamphibious noticed the same change in rpm after the tune. IDK... The only thing I can figure is either there was more torque converter slippage before the tune OR it's an optical illusion because the speedometer was off and you weren't looking at rpm vs actual speed.
 

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Dont swet the warranty, your tuner has the stock factory tune stored in it if you have to go in to the steelership for work inatall the stock tune they wont know what your up to( just take your tuner out of the glove box) them guys are sneekey the root around
Yup, unload that tune right away and take it to the dealership. If they care, that'll tip off a lot of things they'll know you had a programmer installed. (Key cycles)
 

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I spoke with the dealer (service manager} when i first bought my jeep and he actually set my computer after i got my 35"s He could only set it to the tallest tire he had in the dealer computer ,and that made a unbelievable change and he has no problem w a superchips or other brand tunesr.I cant wait to save some cash and get the whole package!!!!I went from a stock unlimited tire to a 35" and the sluggsihness and shifting suck but just w the dealer tune made it like i was driving a new jeep.Has anyone else had any luck w the dealer like this or do i just have a great dealership!!!!??,Just as a step to getting the aftermarket tuner.Now that i think about it it may not be a big difference going from a Rubicon tire size but from such a small unlimited tire to a 35" tire the tune they did was like driving a whole new Jeep :D
 

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Discussion Starter #8
He's talking about after the tune, not after the tire change, right brat?
Yeah, like on my way to work, after I get up to speed (45mph) and am just cruising down the road, the RPMs seem to settle noticeably lower than with stock tires/factory tune.

anyone else had any luck w the dealer like this or do i just have a great dealership!!!!??,
I found a local dealer with what seems to be a very cool service manager, but it's an hour away (one direction). Figures. :D

Now that i think about it it may not be a big difference going from a Rubicon tire size but from such a small unlimited tire to a 35" tire the tune they did was like driving a whole new Jeep :D
How big are the stock tires on the X? I thought they were 32" for both the Saraha and the Rubicon, I didn't think the X was too much smaller?
 

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How big are the stock tires on the X? I thought they were 32" for both the Saraha and the Rubicon, I didn't think the X was too much smaller?
The steel wheel models are 225/75r16 (29.3) and the alloy models are 245/75r16 (30.5)
 

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Who's got the best price on the superchips programmer. I'm interested.... and want to find out more about it.
 

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Who's got the best price on the superchips programmer. I'm interested.... and want to find out more about it.
$339 is about the going price. Sometimes you can find them on special for $299. Watch the for sale forum, one or two used units come up for sale every month. Just make sure the seller has returned their vehicle to stock or you'll have to pay $100 for a VIN unlock.
 

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Is it possible to buy one that I could use for my JK and my wife's liberty?


My mistake. I looked and saw they don't offer a programmer for the liberty...
 

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Discussion Starter #14
It looks like once you make a change to a vehicle, that programmer is locked to that vehicle until you undo that change. So no real way of doing multiple vehicles with one.
 

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Just bought mine from 4wheelparts $314 shipped to my door
so far I am running the 91 octane tune I am a little confused though thought I could lock both my lockers in 4 hi bu you can only do one or the other. Also the tpms I can only get it to go to 26 psi not disable
 

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As previously mentioned, I am very intrigued by the superchips product. I've always read or heard about how you can 'chip' your vehicle to get better performance. I will add this product to my wishlist. I have one more question I was hoping could be answered....

I bought my '10 JK unlimited sport (automatic) almost 4 weeks ago. I'm not sure how soon I will got to 33 or 35" tires. It may not be until the stock tires need replacing and since I do about 30k miles a year, it may be as soon as a year from now.

My question:
Will the superchips programmer be beneficial even with the stock 32" goodyears to get better mpg, and performance?

Thanks for any input.

PS - I love being in the jeep community again. I love my JK and find reasons just to go drive it...
 

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so far I am running the 91 octane tune I am a little confused though thought I could lock both my lockers in 4 hi bu you can only do one or the other. Also the tpms I can only get it to go to 26 psi not disable
You can only lock in 1 axel at a time. Now that you have locked your Superchip programmer to your jeep, go do an update on it and you can get an "offroad only" download to disable the TPMS altogether. The programmer just needs to be locked in to a specific vehicle first.
 

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You can only lock in 1 axel at a time. Now that you have locked your Superchip programmer to your jeep, go do an update on it and you can get an "offroad only" download to disable the TPMS altogether. The programmer just needs to be locked in to a specific vehicle first.
I was wondering about that too. Thanks for the info about the TPMS.

So once I download the special offroad only package, if I unlock the programmer, do I loose the ability to use the download, or is it permanent?
 
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