I have noticed that the guys with the cutouts and good exhaust systems make very little from cutouts showing that a good exhaust makes good power. The downpipes are said to make 15whp and all I can see is they don't have cats. Research says the V6 has an odd exhaust pulse that can be evened by an X-pipe that is located as close to the engine as possible, hence where the rear cats are. Personally I would use a magnaflow TRU X muffler in that position, the benefit of an x-pipe and additional sound deadening(yep, getting old)If the X evens the odd pulses of our motor that could be worth a few ponies. For myself I would delete then resonator and add a nice Borla muffler( NO DRONE) Hookers are also said not to drone but I have always used the Borla's as they seem to produce a good amount of low end grunt. The turbo XS version, NOT the ricer variety.
Now, who cares to venture a guess on the power the logs unleash. Hey Rob, how about a free set for the guy/gal who guesses the closest. Also how about selling the headers without the coating for those who wish to do their own heat heat enclosure? With the catless downpipes following them I hope to see 25whp.
You may say I'm a dreamer but I'm not the only one. I'll take 40whp with the system described above

 

I know I'm comparing apples and oranges, but the first modifications I competed back in 2007 with my 06 Charger was Mopar LT's, highflows, custom Magnaflow. My base stock dyno put down 296 rwhp, after just those bolt-on mods, 323 rwhp. Considering it's a 4,300 lbs. vehicle, with stock tune at that point I was pretty impressed.

Rob does offer highflows as an option, and I'm looking for a complete system (likely next spring). So with these headers currently under R&D, and down pipes, this looks pretty good as a combo setup.

 

I just added robs catless downpipes with cutouts (I had to modify every piece to suit my setup), I added 2 high flow cats in them just behind the mounting bracket to keep legal, I put in Magnaflow true X muffler where the rear cats are suppose to be and I have 2 magnaflow mufflers at the end with stock tips. My car is not loud at all anymore. A stern growl when I hit the gas but that's it. No more change rattling in the bin or screaming at the passenger! Power gain I have no idea. Has not been on a dyno since 2010 I think. The trusty "butt dyno" does not work however the 11's left on the road behind me may be a few feet longer.........

 

Rob's log style headers making power will be tied in with other mods you have. Sure equal length long tubes would be desired if there was only room. Then there's the steering box in the way. As a compromise,I'll be going with Rob's larger diameter log headers that I want have to remove every time I want to change out 12 spark plugs. As you already know,the SRT-6 has 4 cat's. Two under the hood heating up the engine compartment and two under the car. Then the SRT-6 has a factory flattened out down tube on the drivers underside. When changing all this out,it will work nicely with other mods to bring out power. After installing EuroCharged 185 crank pulley, then the rest being NeedsWings mods, headers,down tubes,two high flow cats,custom x-pipe,custom intakes,teflon y-pipe,DCAI,90MM supercharger snout with 90MM Power Plus BBK 90MM,pulley saver kit,then the headers are a must have. Any custom header's power gain from headers will vary with each car's mods. Squirrel Crusher

 

I asked Rob to throw my Magnaflow Tru-X muffler in the garbage can. If you catch him before the trash truck comes and pay postage,he will most likely send it to you. Squirrel Crusher

 

Based on my sig, would you guess that adding the log headers would require more fuel? I've been tring to avoid changing injectors etc...

 

I'm going with 440cc BOSCH drop in injectors off ebay for $190. shipped. Turns out I need the injectors with the 178/70 combo & Jerry sees no tuning issue with them as I was hesitant also especially when I thought I had to go with 550's. Yeah, the exhaust will lean the fuel system but will not tax the 440cc inj's.

Da55, I was looking at Squirell Cruscher's mods and not yours. You may be OK with your mods and the addition of the headers. While it's true a freeflow exhaust will lean the motor you should be OK with the rest of your mods. The part about changing the injectors is the fact that the intake manifolds have to be removed/installed and this unknown territory for me even though I farm out the work. Do you have a wideband O2 sensor, I missed that? If not then you need to get one. That will tell you if you need injectors but first there is always an adjustable regulator. I'd get the regulator, then a wideband. By then maybe the headers will be ready and you will know if injectors are needed. I say no you will not but the mods I mentioned are shoukd haves anyways.

 

Well, I gave my ideal system as per bench racing. Logs, downpipes, internal x-pipe muffler up close to the motor, resonator delete and a nice Borla muffler(no drone and good bottom end torque). Nobody else interested in venturing a guess or posting what you have done and the results you have achieved? Another thing is my motor should run 40-45% more than stock boost and have that amount of extra fuel to expel. Almost half again than stock. The stock system has proven good and cutouts for the most part do not offer even a tenth because the users have a good system after where the rear cats would have been making the cutouts not worth a darn. I've held back because 15whp for a $1500. exhaust system is way out of my return on the dollar. maybe the logs will release a bunch of exhaust gasses making the rest of the exhaust mods work like they should and yield the power one would would expct?