that is a big canister and might be too big. What I have found is adding too much causes too much of a loss in the upper end. Adding back that ball valve gets it back and allows you to shift the torque peak up the rpms to where you want it.

For reference, google tells me my PLs are:
15.0" x 1.5" PL = 26.5 CI,
12.0" x 1.5" = 21.2 CI,
22" x 0.75" =9.7 CI
for a total of approx 57 CI. On my setup with the ball valve I'm able to choke down the flow in & out of the 12" PL which allows the shift in the torque peak. The 15 x 1.5" is always connected, the 22 x 0.75" is always connected & the 12" one has the ball valve on it.

Also, keep in mind I have the '03 intake manifold that has shorter runners which will also shift power up the rpms some.

Update on mpg drive... been able to keep my foot out of it and use cruise control it is tough! But, the mpg test is important and I will stick it out.. 113 miles so far on this tank, have 1.5 more work commutes to go lol.

 

Thanks for the info on sizes Steve, i know you have the newer intake, but i'm going to get close to you're sizes of the PL's to see which works best in my case.

 

huh, thought I posted mpg numbers... got exactly 18.0mpg over 230 miles.. almost all commute miles, had 1 detour & a good amount of rush hour traffic on 1 trip home.

 

Updated the sheet metal inside the airbox today, made a piece that fits much better and has coverage side to side on both ends of the open air box. Now, no more intake noise. Intake noise = turbulence. Did a 40ish mile drive on hiway & back roads to get the LTFTs the opportunity to dial itself back in. Not sure how much driving it takes but it is better now than just after the install.

One observation, about half way thru the drive I noticed fewer downshifts under certain conditions. I have the ball valve set for more top end power vs bottom end (resulting in more sensitive throttle to downshifts for some reason, fun to drive). I figure I have another 100~150 miles to go before LTFTs are good to go.

 

Back from vacation, intended to do a mpg comparison on the work commute but have already failed (jet lag lol) Will need to do a do-over on it & will fill it back up today after work. It is difficult to keep the foot out of it.,

Next week I plan to put the cat back exhaust in & then the Jeep TCM back see how it does with the trans programming tweaks. Or... I may just do it all and get it over with. Been working on the wifes JK lately, have a 2" y-pipe from Magnaflow ready to go in (she has a plugged cat on one side). Planning to start programming it soon as well.

 

Update.... Stars never aligned for the DTCM mpg test, truck got the tap for a road trip across state so I ran the JTCM 5spd controller. 775.3 miles, 46.275 gallons for 16.754 mpg. These tanks were 100% DGAS, on the way out there were 3 of us & a light load in the bed. Interstate speeds were in the 75-85 mph range with a couple of times it being a bit more, 3x there were either construction traffic delays (stop & go) or just too many cars on the road (also stop & go) for 30~45 minutes. One of those tanks on the return trip, 137.9 miles, with the traffic delay gave 18.470 mpg over 137.9 miles (filled up at the end of the trip).

The JTCM did OK but at higher speeds it was reluctant to downshift still. I expected this and will need to give the tuning a shot again to see if it can be improved. As of now the JTCM is in there for a 3 day mpg commute test.

 

16.90* mpg over 239.3 miles... A drop from the DTCM which has been mid 17s.

 

hmmm, Jeep TCM was designed for lower the engine noise at highway speeds for complaining Jeep owners, means lowering the RPM's to reduce noise.

Seems with you're 4x4, 4 doors version the vehicle weight is the reason for a higer fuel consumption, than my ligth weight 4x2 single cab.

At least you gave it a shot, and knows for sure this ain't gonna help you.

 

Catback exhaust install done, test drive time. Expectation is no change in performance, fuel trims will tell the tale.

 

I think it is a combination of the 3.55 gears & oversized tires, this leading to rpms being too low (1600~1650) in the cruise zone on the way to work. It just seems to be happier in the 1800-1900 rpm range for mpg's.

Just got back from an extended drive after the cat back install. Super happy with this kit, it is just a tad bit louder than the oem setup. What I did not expect was the upper rpms performance. There is a freeway on-ramp that I have been using as a guide to judge performance changes. The bench mark is a spot where the grass ends. When I started using this ramp a few months back I was hitting 60 as I passed the reference point. I've seen the speed rise with the mods and just drove this ramp this morning (I stop off to the side at the beginning of the ramp before doing a hard acceleration (no WOT, no wideband O2 for tuning). On this mornings ramp drive I'd hit the 60 mph mark approx 10' in front of the reference. After the cat back install that same run it hit the 60 mph mark 30-35' in front of the reference. This took me by surprise for sure. I still have the PL mod valve to play with but will change it later after the mpg run to work next week.

Another thing to note, the Torque app LOM indicated 22.3 mpg when I got back from the drive. I have never seen it that high on these drives and typically its 20-20.5 mpg. Note that the commute mpg's with the DTCM was 17.5's every time I'd tested it. Planning to test over 3 days next weeks work commute.

Overall, I am shocked at how much power I have been able to get out of this truck. Super happy with it. While there have been very noticeable gains with individual mods, the end result with optimizing the intake, exhaust & fuel injection (remember 12 hole injectors dialed in with HPT). Sadly, I think this might be the end to the mods. The only things left would be cams & head work & those are currently not on the table. What will happen eventually is a motor swap with the Jeep HO motor, but that is off in the distance when the current motor gives up.