I have a ceramic coated aftermarket better flowing header and have been told wrapping the header will keep heat in and better MPG, i have to pull it anyway to do a new gasket so while its off i thought to do it?
Also while intake has to come off ive gone to the better flowing one off the 2000 jeep intake manifold which adds 15 hp to the older 4.0 jeep motors that have the bad flowing intake manifold. while changing out my old intake manifold i have been told a larger throttle body is better for mpg too and will go well with the new intake and exhaust combination.
I already have a 3 inch intake Warm air off the header. i guess my header wont be as hot as it used to be if i wrap it just curious probably wont affect the wai that much.
95 JEEP CHEROKEE XJ
OTHER FREE MPG THINGS TOO
The header wrap keeps engine bay temps down and is a little counter productive to what you are going for. Wrapping the exhaust from the header down can keep exhaust gas temps up and therefore EGV stays up but you'll lose a lot of your WAI functionality if you wrap the header.
My truck drives mostly in urban areas. My average speed reported by Scangauge is usually only about 15 - 20 MPH. When I installed the grille block I made sure that the holes in the block were put right in front of the oil and tranny coolers. I agree. Those things need to breathe, but you can still do a grille block.
header wrap will kill your ceramic coating over time. a larger tb is definitely NOT good for mpg. it will be a lot easier to throw too much fuel in the motor. you will improve throttle response though...
don't waste your time or time will waste you
In my observations of the 4.0L I6, I find that staying out of 2500+ RPM is ideal. I do not gain any power above 2500. To see for your self, try shifting at 1800 RPMs and no higher. The engine has plenty of low end torque and is very hard to stall under load.
Throwing money on larger TB and header wrap is an effort to increase HP which leads to more fuel consumption.