So will deleting my muffler and replacing with 3 1/2 incy pipe work better?
The muffler is a dog. Get rid of it. But if you replace it with a straight pipe, your neighbors and most adults will frown at you because of the obnoxious racket it makes. Instead, replace the muffler with a Walker Big Truck Muffler ( BTM) #21470, also called a Walker or Dynomax RV muffler. Your 3.5" factory stainless exhaust system is as good as it gets after you get rid of the restrictive muffler, so the Walker BTM is a great mod and not very expensive. Available to order at NAPA and other auto parts stores, but the best price is Summit Racing:
http://www.summitracing.com/search?keyword=wlk-21470&dds=1
Next mod is air intake. Best is the Ford AIS (air induction system) for 7.3L diesels. You can buy it from any Ford dealer for about $300, or you can order it from our sponsoring Ford parts dealer for a lot less.
Tousley Ford Parts Depot
Then
DO NOT install a tune or chip or programmer that will increase horses until
after you have installed at least a pyrometer and turbo boost gauge. Adding even one more horse to the engine output can result in a melted piston or blown up turbo if you don't "drive by the gauges". Never exceed 1250° pre-turbo exhaust gas temp (EGT) or 25 PSI turbo boost if you want your engine to be a happy, reliable camper.
Where do I go for that tuning you said?
A "tune" means replacing the stock tune in the engine computer (PCM) with something different. Three ways to do that. Easiest and cheapest is to simply have the tuner flash the PCM with a different computer program (tune). Most common way is to install a multi-position chip that has more than one optional tune. And another way is to use a "programmer" black box that includes a few tunes you can choose from.
Sources: Most popular for the well informed 7.3L owner is
www.DP-Tuner.com. An excellent competitor is
www.powerhungryperformance.com . And lots of folks in Texas prefer Tony Wildman's tunes. The following linl is weird, but it works to get to Tony's website:
<SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 16pt">7.3L <I>Power Stroke</I></span>
Custom tunes come in all flavors, from a mild increase in HP and torque to wild that is suitable to win a drag race or sled pull. Any tune that produces more than about 100 HP over stock requires additional mods to take advantage of the extra fuel the tune will throw at the engine. Using DP-Tuner as the example source, he offers 80-economy that's probably his best tune for daily driving with just intake and exhaust mods and gauges. I used 60-tow to tow 8,000-pound 5er, and it was great.
And what areas does it help? Should I tune and not get a chip?
A mild tune wakes up the engine so it's fun to drive. After you drive with 80-economy or 100-performance tune for a while, you'd rather take a whooping than drive without it. For towing, the tow tune adds enough horses that the tranny doesn't have to be downshifted for every little bump in the road. Unless you are a fanatic row-your-own shifter, then you'll appreciate not having to downshift as often so the engine doesn't lug for hills or overpasses. You do know that you must
NEVER allow the engine to lug, right?
You can get above the redline for EGT if you don't drive by the pyrometer, but you have to be doing something your mother would frown at before you can hit the EGT redline of 1,250° pre-turbo EGT.
With a PCM flash (reburn of the computer program in the PCM), you'll have only that one tune. With a chip properly installed, you can have more than one tune, and the capability to "shift on the fly" between tunes. With a programmer (also called a tuner) you'll have more than one tune, but it requires a coupla minutes to change from one tune to the other. Some programmers also included digital gauges and diagnostic capability, so some folks use the programmer instead of investing in gauges.
I had a programmer loaded with DP-tuner tunes, 80-economy, 60-tow, 100-performance, and the best stock tune available for the '99-up 7.3L. I almost always kept it in 60-tow. It ran about the same in 60-tow as it did in 80-economy, so not much incentive to spend the few minutes required to change tunes. 100-Performance produced a bit of black smoke with my mods, so I rarely used it. The best stock tune is needed if you need to drop off the truck at a Ford dealer for diagnostic or engine repair.