19.3 mpg over 220 miles to & from work... no pinging on Arco regular. Going to re-tweek the fuel pump parameter a bit more to see how far it can go. Started at 125-> 115 -> 105. will do 100 next unless there is pinging, then will bump up until it stops. Lower limit is 100.

 

next update done, pings @ low rpm low vacuum conditions. Tried a few things to get it to stop with no luck. Going to get back to it later today/tomorrow and triy again.

 

Update of sorts... have not changed the tune from the above post, pinging stopped. temps are supposed to climb this week, will see if it comes back.

But... on another note, did a 100% dgas tank over the last 2 days, 325+ miles 17.1 mpg. Speeds in the 60-78 mph range with 2 passengers. Was 100% shocked it was that high, was guessing it would be mid 15's.

 

Update... have been gone for the month of July on the planned vacation to Europe (Spain, Portugal, Belgium... Metallica & Formula 1 @ Spa on each end of the trip) so have not had much seat time in the Dak lately.

What I can say is that I have had no audible pinging that I can tell with the increased temps into the upper 80's. I missed the 90's we had in July so no feedback on temps that high but my expectation is there should be none. Truck runs awesome and is fun to drive, if I keep my foot out of it I can see mid 17's for mpg's. Otherwise its mid 15's to mid 16's. Injection duration has a huge part in the mpg's and I currently have it set such that the PCM is adding fuel per the LTFT numbers. This comes at a cost of power... but, with the current setup (listed below) it is still way stronger then it ever was stock.

Mods (2002 4.7 engine)
1) Airaid intake tube wrapped in exhaust wrap, with turning vane installed
2) Airbox valve, 2.5" set to open under low vacuum conditions
3) 70mm Throttle Body
4) 2003 intake manifold (noticeably bumped power on the upper end & worth the effort)
5) Insulated bottom of intake manifold (this was a fail, I saw no improvement in the data I'd collected)
6) Installed heat shield under intake manifold to act as an insulator (this was a fail, I saw no improvement in the data I'd collected)
7) Insulated fuel rail using exhaust wrap
8) Potato launcher mod (as I call it)...this moves the torque down the rpm range and gives a noticeable bump on the bottom end, idle to approx 3k rpms, top end suffers a tad bit
I currently have 1 15" piece & a 2nd 9" piece (iirc) installed. Both of these are wrapped with the exhaust wrap, that made a difference on intake temps.
9) JBA shorty headers, this had a slight bump in overall power but nothing compared to the previous mods
What this did do is fix the intermittent misfire code I had on cylinder #7, have not seen it come back once since the install & approx 5k miles (guessing)
10) 180* t-stat with 3-fan temps set accordingly, mechanical fan delete
11) 12 hole GM injectors
11) HP Tuners to dial it all in

Mods remaining
1) Custom y-pipe with a piece at the collector to allow me to install a "restrictor plate" as needed to meet my preference.
What this means is if the output is 3", it would allow me to insert a restrictor to knock it down to whatever size works best for me.
2) 3" high flow cat
3) 3" cat back exhaust kit
4) Adjustable vacuum switch & solenoid installed off the intake manifold to shut off the Potato launcher mod & air box valve (this valve is normally open so no real change there, it is tied to the IM already) under high load conditions

For a $2100 (net after selling the shell) truck, it has served me well and continues to be a solid performer.

Hope this helps the next guy... a lot of this would apply to other engines but would need experimentation to understand what if any performance changes occur.

 

This was massively informational. It maybe too much to ask. But could you help me learn how to get where you are with HPT. I may have a similar conundrum. As I have a special ordered 4.7L H/O with 45 state emissions. It's an 06, but knowledge and experience would be greatly appreciated

 

Well finally some news, the HO engine isn't going to happen, seller wanted more when i told him i was interested....

Made a propper "Potato Launcher" Steve, and i'm impressed, should have done this way earlier.

I had a kind of Turbo lag with the Jeep TCM, now it's gone, pulls more evenly without hestitation through all the rpm's, so very satisfied with it.

Only have it done this past weekend, so no results for fuel economy yet, but i'll keep you guys informed.


my "PotatoLauncher"

 

Previous HPT experience is on the CTD Ram... going over to the Dak took little time to understand there is not much that can be tuned on my year Dak. There were only 3 tweeks I did to it, 1st got the e-fan working where I wanted it, the 2nd was setting the injection pulse width where I wanted it after doing the 12 hole injector swap and lastly, getting the timing advanced where I would not have pinging on the crappiest fuel. Overall there was so much more gained by doing the hardware mods before the tuning. Tuning & headers did not give a whole lot of a bump in performance, it was there but nothing like the other mods. If those were done 1st I might have different feedback but thats what I saw.

The biggest hitters in no particular order were:
1) potato launcher mod (aka PL)... this mod gave a very noticeable bump in bottom end torque. What I found it to do is shift the power down the rpms but it sacrificed some top end. (later addressed with a newer short runner intake manifold swap, see below).
.. Note this mod cost something like $50 in parts to make and by far had the biggest impact. I did this mod on a neighbors jeep GC with the 4.7 & she was shocked at the performance change & happy about the mpg bump.
2) 70mm TB
3) turning vane in the airaid intake tube... this cut the aero pinch point in the intake tube in half which gave better flow overall and gave another noticeable bump in performance.
4) '03 intake manifold swap... this bumped power up the rpms and showed me that the PL could be tweeked to get performance to my liking
5) fuel rail wrap/insulation, bump in bottom-mid range power
6) 12 hole injectors could not determine if this had a performance change or not as these went in with the IM. I did find while monitoring the LTFT that it was running rich, HPT helped dial it in with the injector pulse width changes


Other notable gains came from the airbox mod (I'd go bigger on the valve if there were room for it, it helped top end) and wrapping the intake tube to prevent heat soak, insulating the coolant lines across the IM to contain the heat.

From the tuning perspective, (your original post)... the hpt helped me to dial it all in and was limited to just the pulse width and timing. Someday I may go back and do a performance tune where it runs on 93 oct & the injector pulse width is bumped back up (currently pulled back so LTFT indicates its adding fuel within its capabilities and is running on the lean side for mpg's, no pinging).

If you have questions dont hesitate to ask, happy to help.

 

NICE!! Glad to see it is being installed else where on the 4.7. I have had a couple of guys try it on 4 cylinder engines but it did not have the impact we thought it should have had. I suspect the engines ability to draw a vacuum has an impact on it and if we'd gone smaller with their setup there might have been a bump. On the wifes jeep with the 3.8L V6 there was a bump but it was not as strong as the Dak's 4.7. Out on the hiway i got her mpg's up over 20 with a peak of 21.x (forget exactly what it was but over 21) on a couple of trips but the city mpg's seemed to suffer. Its got massive 18" heavy e-rated tires on it so not surprised her city mpg's suck. It really needs a re-gear.

Couple of recommendations on your setup... 1) insulate the fuel rails & cross-over tube 2) insulate that intake tube 3) look at doing a turning vane in it as well. Only thing to be aware of is the divider needs to be inserted such that the incoming airflow keeps the 2 pieces interlocked so it cant come loose. Mines been in there for something like 20k miles now & zero issues.

MPG's... last tank I made an effort to keep my foot out of it and got a 17.5 mpg on the tank to & from work. This tank I decided to bump the speed a bit based on manifold vacuum readings. So far it looks promising based on fuel used (per the gauge) vs miles driven (close to 200 miles & approx 1/3 tank used), will see on Friday.

Another mod coming when I get time to work on it... I have a vacuum switch that I picked up to control a vacuum solenoid I plucked from a wrecking yard car. The goal is to kill the PL mod when vacuum signal gets below say 5 inhg. I believe this is going to help power further under those conditions but I wont know until I play with it.

 

one thing I may have forgotten to mention.... I dont recall when this started, the engine was popping a mis-fire PID on cylinder 7, could never figure out exactly why but certain combinations mentioned above did not give a code. It had me scratching my head for the longest time. A guy over on the HPT forum commented on this and it was tied to the firing order having cylinders 7 & 5 in the order as to being part of the issue. i was ready to try a colder autolite plug in cyl 7 to see if that would fix it but never got it installed, did the header install first and that code went away, never came back. I suspect the exhaust heat back at the #7 cylinder was part of the root cause of that issue. Headers have been in something like 9 months now and about 10k miles since the install & zero mis-fire codes.

 

Thanks for all you're shared info and updates Steve.

I'm going to work something out on the turning vane and i bought the heat shield/insulation stuff allready so this is going on as welll.

This afternoon when i got home, i touch the PL and intake tube to see how warm they would be, and they were warm, something like 30 Celcius i guess, despite te fact the PL is mounted directly behind my hoodscoop.

Thought it would be much cooler, so like you said i'm going to wrap those.

We'll keep in touch greetz Ludo.