Thought some of your might like to know: First of all after much study here, I got a 3.5" MBRP downpipe instead of 4" as some have problems with clearance in 4". I am not sure the 4" downpipe is necessary anyway unless you are making a 500 HP Drag truck...
I belled it out to 4" at the bottom and ran as straight back as possible, kitty gone, straight flow through glass pack sort of 2' muffler 4" straight through, up slightly over the rear axle and turned out at 45 degrees aft of the dually mud flap... Results as follows-
GREAT.. not overbearing, but definite a little Old School Hot Rod V-8 Rumble when you get on it. A little mild rev at idle even, gives that cool rumble effect. I was worried about Highway drone, but while you can lightly hear it and it feels good, it is not overbearing and you don't need to turn the stereo up or anything.
When you romp on it, they hear you even in the car behind you. IT DOES SOUND GOOD... But I am a 56 Y.O. Businessman, and it is not "over the top" as they say here, not too much, just a little rumble of the power it is...
Back pressure fuel economy:
I cannot give you figures yet, but it looks like about 4-5% better on the "lie o meter" which is fairly accurate on my truck on a long highway trip and hand calculates out about the same as the meter says.. It is showing that 4-5% better fuel economy still running stock Tune on the SCT
Maybe, maybe a slight drop.. But nothing to speak of right now..
Now Eric at Innovative Diesel, is a CHAMPION,
and has written a Tune for the SCT. I should have some figures soon and will update, but I am striving for a 10-15% increase in fuel economy. We do long range work in Australia... It is not so much for economy as RANGE of available fuel...
07, King Ranch, F-350 Dually, LWB CC FX4 and loaded to 4300-4500 kg around 9900 lbs say with big tanks and tool boxes full..
But love my toys going with me
SCT LIVEWIRE, Bocar Bull Bar, 16.5 Warn coming, big hitch, 5th wheel ball mount, LightForce 240mm HID driving lights, UHF radio...
INTERESTING FUEL NOTE:
Eric has said that a Street or Extreme Street will get better fuel economy if you keep your foot out of it and drive lightly
, but of course not safe for towing......
He has sent me a Tow Safe tune. QUESTION OF MERIT: There must be a way to tell what tune you left the truck in, if you have two major Tunes loaded... Anybody have a way?? Extreme or Street around town, but when hooking up to tow a van switch back... Easy to make a boo-boo... Must be some way to tell where you left it?
Best regards to you all in America... We love your trucks ( it is that or rice grinders here in Australia, and they have no power for towing )
Had an 08 Silverado, had... BACK TO A FORD