Now we're getting into the nasty stuff where we REALLY need to take the specific application in mind.
Worst Nightmare wrote:I just want to explain a little further......
To be exact: I have a Dodge Ram 5.9 (360ci) V8.
Glasswolf - stick to things you know (maybe car audio?) but definitely not new car/truck performance.
I'm not trying to be a jerk, but ALLLLLLLLL new transmissions have OVERDRIVE, or 5 speed, which negates your gas mileage because of overgearing theory.
It's still a lower gear, and will still eat away your mileage in your average application. In your case, you're talking about a heavy truck that will most likely benefit from the torque multiplication in a real world application (passing, steep hills, etc.). You've also added larger tires in the process, which makes the steep gear comparatively less aggressive. Plus you have to consider that trucks get crap for gas mileage to begin with, most people wouldn't even notice the drop in economy considering how much your mileage will already vary due to driving conditions.
With a lighter vehicle like a Mustang, Camaro, Charger, etc., I feel a 3.73 is about as steep as you need to go for a good all around combination of acceleration and fuel economy. You usually won't kill your top speed either since the extra torque multiplication lets you wind higher in OD.
Let's keep it civil here, though

:. He knows a lot about building performance in a wide variety of applications. Noone ever became a master of anything by believing that he/she knows more than those around him. Usually it results in getting your ass handed to you by your competition :) .
Worst Nightmare wrote:and ceramic coating not even relevent! My JBA titanium ceramic only controls under hood temps. (they claim!)
Sure it's relevant. The exhaust system is responsible for removing half the heat of an engine. You'd much rather have that heat underneath the car than you would radiating to the rest of the engine, not just for power's sake, but also for the reliability of the electronics and "soft parts" like hoses, wires, belts, etc. You'll also have gains since the entire induction system is much cooler, but it's just not something most people are going to measure because it's a bit too "real world". I don't know of anyone that runs a car on a dyno with a hot engine bay, a closed hood, and having run the car for hours

. All are trying to keep things nice and cool and pull the biggest power numbers they can, esp. considering that dyno runs aren't cheap.