Picked up a set cheap, new for $400 bux. Pulled the oem manifolds and am 2 collector gaskets away from re-assembly. Got some ??? Stage 8 locking bolts to keep the headers clamped to the head & new collector bolts that came with the headers.

Reviewers in the past have claimed better bottom end response however I think that is with the y-pipe upgrade. My expectations are I'll have to re-tweek the intake setup again to match any change in performance to my liking.

Still have not attempted another HPT download, it is said to be working now so I think it will be in the near future. Again, if I never get to update the tune with HPT, the motor has gained a good amount of power as it is now. Anyone driving it would assume it is tuned.

 

not sure if this helps, I did not install , my exhaust went bad at the flange/donut/bolt.
I found a shop in Raleigh that had good feedback for years doing exhaust. I bought the JBA ceramic Mopar shorty headers,
and would suggest RemFlex gasket !
I let him know I wanted a 3" single exhaust , the Y-pipe had to be 3" , ( the choking point for the stock exhaust )
He welded in the two bungs for Mopar sensors. It has been 8 years of trouble free exhuast , great magnaflow sound, retained lots of torque.
At the same time I had them install a Mopar performance lightweight starter ?

 

Install 95% done... have to pull the y-pipe connections loose gain, bracket for the transfer case to exhaust hanger will not go on, going to loosen it all up and see if I can get it to fit as expected. I did note that the passenger side collector joint is not sitting as i'd expect so will loosen it all up and do it again.

I have a 4wd & plan to get the y-pipe fabbed the right way, no pinch points. As I was working on this one thing occurred to me that might actually help with that pinch point and that would be to do an exhaust wrap on it in an effort to keep it hotter than it would be normally. would probably wrap from the collector joint down to the passenger side joint, would do both. Will experiment with it before I swap the pipe out.

 

Throttle body hat recommendation for you... I have learned that a turning vane anywhere there is a tight bend will give a noticeable bump in power. Did this on the Dak in the intake tube, wifes Jeep JK at a 60* bend (barely noticeable and might not be enough of a bump to make it worth it) and the Ram's intake tube (afe torque tube) from the air box to the turbo. I did both bends on the Ram and its change was extremely noticeable.

Years back I had a 5.9 gasser in a 1500, ran gibson headers, 52mm TB, crower 1.7's (iirc) and genuine RT heads with the 2.02 valves (iirc) along with a K&N intake kit. Had I known what I know now, I would have fabbed up a turning vane at the air hat to reduce the turbulence near the throttle body.

Another near tip is to create a divider, I did 4 on the ram's air filter, to reduce turbulence as air enters the filter. Was shocked at how much of a change that did on the Ram. I also did this to the Dak (which was the 1st experiment on this mod) and was really pleased with it. All 3 rides we have include this mod. It seems really simple and easy to dismiss as not worth doing but... until you have done it and see the light you will always do it. FWIW, I used 5" plastic edging found at home depot for these mods, easy to cut, easy to mold and work with.

 

I assumed pushing more air into the filter /air box would be beneficial ?

 

Anything you can do to help the engine breath better, means more power.

 

by adding a turning vane above the TB you would be reducing the turbulence above the inlet. Ideally, you'd want a straight shot into the TB but you are stuck with a 90* bend.

Watch this video... it is not to long but has great explanations on why turning vanes are beneficial.


FWIW, (not sure if I mentioned this) I did a vane on the inside of my wifes Jeep JK oversized intake tube that attaches to a 4.7 v8 TB I installed to replace the dinky one that came with it (plug & play). The hose I used had a 60* bend in it and when putting in this vane, I did not notice anything to get excited about. There might have been a slight bump in power but it was hard to tell. That told me that there is a point at which a vane will not help. The best thing to do is experiment with it and see how it works on your setup.

The key thing to remember though is in a tube, the supporting piece that keeps the vane roughly centered, needs to be interlocked in the vane itself and when installed, the airflow would actually put pressure on its edge to keep it wedged in the vane, it cannot come out.

Also mentioned above (iirc, not looking at my post) a divider inside the airbox will also reduce turbulence onthe air flowing into the filter. Believe it or not, that actually has an impact. That mod is on all 3 rides, Ram, Dak & Jeep.

 

Header install done & took it for a long drive to help get the fuel trims done (60+ miles). Initial reaction while trims are at default settings was WOW, can feel a difference out of the garage. But, as time goes on & trims get dialed in I am able to compare against stock manifolds. Definitely more power throughout the rpm range and really happy with how it runs.

My test hill I hit up towards the end of the drive to compare against all the other drives up that hill...

Before: doing 60~62 mph speeds would drop and at approx 1/2 way up the hill it would downshift as I try to maintain 60.

After: (only 1x on the hill so far) the truck made it up approx 3/4 of the way before a downshift.


Pretty happy with how it runs and considering it is still running the STOCK tune, there is more on the table. Word has it HPT is not working for the latest interface (MP3) and some have had trouble with the MPV2+ interface (me included as my ECU was not supported yet). I am told I am good to go. I have a 2nd ECU that I will sacrifice in an attempt to get tuning going and will make that attempt in a couple of months. Minimally all I want is more timing, higher idle speed and lower fan on temp. There was (before header swap) an issue with the cylinder #7 misfire, this oddly did not occur in the 1st 60 miles of driving. I used to be able to see it via freeze frame data before a CE was set. I checked this today when I got home and there was nothing. Surprised by that.

anyways, update done... :-)

 

I am still shocked at how much I have pulled out of this 4.7 with stock programming. Considering a dyno visit to see where it sits.

 

265ish miles gave 15.9 mpg of approx 90% eco driving... Lots of late afternoon rush hour traffic and rain everyday. Still on stock programming.

Performance wise overall it is night & day compared to when I got it. All of the mods have made this truck fun to drive and it hardly gets a sweat doing 70+. The only thing I would possibly change (besides the stock programming) would be 3.92 gears.

I still plan on doing the y-pipe in ~2-3 months followed by cat back (and probably a new cat) as all of that looks original.