Why bother with trying to get more power out of the engine? Keep it all stock so it stays reliable and re-gear the rear end. I bet going from say a 3.73 to a 4.10 will make enough of an improvement for you.

 

already 4 10 from the factory

 

then 4.23, 4.56 5.10...

 

No one makes 4.23 for the Ranger axles.

 

But they make a 4.30?

 

Only if your 2wd, they don't make it for front axle.

 

i seem to remember a 4.23 for the mustang carriers, but i could be wrong, i know they did make both a 4.10 and 4.11 for mustangs (for different years)

 

Yes...thats not a ranger though. Common gears in Rangers are 3.73, 4.10, 4.56 and 4.88. Anything lower than that normally requires stronger axles anyway.

 

or portal boxes :D they take the stress off the axles, by changing the ratio further at the wheels

 

I am not a 4.0L Tech so I could be wrong but an internal combustion engine is nothing but an air pump; more in / more out, it is that easy !
Some motors will respond to modifications more than other but basic increases in the air in and out theory should result in gains in either torque or horse power.

When you talk increasing the air flow through the motor you will need to address the Camshaft also.
Add more air at the intake without corresponding increases in valve lift and duration and you will not see much increase.
Headers are the one thing on most engines that are restrictive enough in OEM Form so when you change to a tubular header you will see some response. How much hard to say, but you will notice the most change in HP and Torque IF you air more air in and change the cam too.
One way to make a difference in the cam lift/duration instead of changing the cam is to increasing the rocker arm ratio of the OEM Rocker Arms, adding a Roller Rocker at the same time deceases friction.
Go from say a 1.6 to a 1.7 Rocker Ratio and you effectively increase the lift of the cam which in theory should increase the torque for a seat of the pant type of response and may help on the top end HP too.

How a 4.0L will respond to these mods, IMHO… if you do all three, Intake, Cam/rockers and headers, the engine has to make more power, how much I can’t say.

p.s. Don’t forget to alter the chip or add a power chip to compensate for the extra air going through the engine.

 

to me regearing not a valid opinion, after cost of gears/ supporting parts/ cost of installation no longer cost effective plus when i go to canada ( about 9 hr trip- the extra revving to me kills the mpg and reliability) other than an electric fan i don't have a aftermarket stereo, lighting, etc to draw extra and even if rather change the alternator than a motor.. i know regearing would make a difference- did in my mustang .. i know the parts i mentioned won't turn it into a street weapon ( i wish though lol ) but other than perhaps the efan don't have an adverse affect on mpg or reliabilty

 

To answer your first question:

Usually the thought has been that if you add free flowing Tubular Headers with not much else then you will bring your engine to OEM Specs, MAYBE a little more but don’t count on it.
Header and Intake improvement allow for other added performance parts to work effectively and work the way the performance part should.

Sometimes all you get from Headers and Intake Mods is added noise and some people think they are getting more POWER.

 

lol like ricers