I've been running the superchips for about 4 years now and I love it. The other day I figured it was time to update the actual device via my computer. After plugging it in and downloading the spark program, it had an update and installed it.

Does anyone know what this update does? I run the 87 octane tune. Is it a better 87 tune now possibly? Any information out there on this?

Second question - I am running KM2's 305 70 r16. With 30 psi in the tires the entire height of the tire sitting on the ground measures to be just shy of 32". However on TireRack and BF Goodrich website it says actual tire diameter is 33.1".

What should I put into the superchips? I feel the jeep runs and shifts faster when I have it programmed at 33" rather than 32". As of right now I split the difference and put in 32.5.

Just an FYI for everyone out there. When I took it to the dealer for some warranty work I returned it to stock. When I reinstalled the 87 tune, I didn't realize I had to do the tires size over again. I think I was driving around with the tires set to 30.75. Maybe coming up now to 32.5 is the reason why I am feeling such a difference?

 

I haven't found anything indicating what is in the updates. Just that there is an update, and then a note that it was installed and there are no more updates. Kinda hinky.

The documentation tells you to measure the tire and plug that number in, not to use the mfg's spec. That will get your speedo/odo accurate. If you want to play with the height to mess with the shift points, go for it, the speedo will just be off. (but, double check the speedo with gps. Mine was never accurate with the flashpaq using measured tire height. It was accurate with the ProCal)

 

I just brought my '13 back to stock to have a small recall performed. While there, they also did 2 software updates, PCM and TCM (good thing I put it back to stock!). I had to update my FlashPaq to recognize these as stock tunes in order to put the 87 tune back on the Jeep. Maybe that's what you're seeing updated by SuperChips?

 

Is it possible that the manufacture says 33 but in reality it measures under 32? Over an inch difference seems like a lot. I can see maybe losing 1/4" tread tops but that still leaves 3/4" from the weight of the vehicle? Is this possible?

 

Yea honestly, the spark program is not the greatest and I was having problems with it so I never really updated it. Finally got windows 7 to install the driver for the superchips correctly so that's when I watched it update.

I said great! It's updating. Now the real question is....What did it update and will this update be transferred to my vehicle?

 

Tire heights vary about as much as actual lift heights gained from different mfg's coils .

BFG's are fairly well known to run small, Goodyear mtr/k's I think are known to be more accurate to the mfg's listed height. Add vehicle weight, and close to an inch less than spec is normal. 1.5" less is not unheard of. Read through a few threads before you purchase your next set so you can get an idea of what actual tire height you can expect.

Also, when you are reading replies on tire heights, take it with a grain of salt. Many people just regurgitate the mfg spec without ever measuring. Some will measure the unloaded spare, others will measure the front tire under full vehicle weight. And when measuring, the tires could have left the shop at 50psi, or they could be dropped to 28-30 for a good contact patch, or maybe they were measured on the trail while aired down. Rim width can also vary the height a bit. You just don't know what the story is when reading all of the various replies...

 

Thanks for the good info. I'm gonna put them at 28-30 psi which is normally what I run. Wait till the morning and then measure all 4 tires and take the average.lol

Seems that this way in getting the best of all worlds. Appreciate the info.

As for the tuner....I guess I will just have to wonder what the update did for a while. Maybe superchips will become like any and every other company that lists what a firmware update changes so people can make informed decisions on updating the product.