Ram air intake question

[Dr.Spank]

I been reading and reading on a short ram air intake and the affect on millage and i keep getting conflicting answers..

So let me ask here where everyone has a similar truck to mine..
I have the 5.4 V8 (4wd)

If I add an after market ram air, will my mileage decrease or will it increase or possibly stay the same??
I am not a mechanic by any means, so forgive me if this is a stupid question.

A friend of mine put one in his nissan frontier P/U and he claims a 2mpg LOSS but others in different forums are swearing about 3-5 mpg gain.

 

[dj_mindframe_99]

let me tell you what I did.

I have a 99 Exp. E.B. 5.4 AWD, I did the gotts mod, then to that I attached the factory half of the air filter case, then inside that I mounted my K&N FIPK intake. it insures the filter gets nice cold bursts of air, and not the hot air from the engine comp. however I did several mods at once for a total of about 1-1.5 MPG gain.

remember these are big trucks, you wont see much of a gain outside of an exhaust with long headers high flow cats, H-pipe to hold torque, and dual exhaust. or a supercharger.
Changing the heads, camshaft and cam gears. things like that. even if you do the GOTTS, the FIPK, the mass air sensor, a larger Throttle body, and maybe a spacer for good measure, you're not really going to see a ton of gains, just mild responses and that seat-of-the-pants feel.

but dont get discouraged, I did a lot of the bolt-on upgrades and it did make a noticable difference. I have more upgrades for more H.P. TQ. and MPG increases.

When all is said and done I hope to have a 99 E.B. with 400+ HP/Torque, that gets 18 mpg highway or more.

 

[ktrjones12]

I been reading and reading on a short ram air intake and the affect on millage and i keep getting conflicting answers..

So let me ask here where everyone has a similar truck to mine..
I have the 5.4 V8 (4wd)

If I add an after market ram air, will my mileage decrease or will it increase or possibly stay the same??
I am not a mechanic by any means, so forgive me if this is a stupid question.

A friend of mine put one in his nissan frontier P/U and he claims a 2mpg LOSS but others in different forums are swearing about 3-5 mpg gain.

It's true that there are different story for such addition of ram air intake. From what I have seen so far from ram air intakes, it really doesn't do anything for you until you are at high speeds, like 80 or more. You get more from cowl induction than piping it in from the front.

 

[Thermo]

Dr. Spank, there are a few factors that need to be taken into account here. The big ones being "how easy is the cold air getting to the filter" and "how easy is the air getting from the filter to the motor"? You can be dumping tons of ice cold air to the filter, but if the intake is restrictive, then it is doing you no good. The opposite is true if you are dumping hot air to the filter, but the intake is able to pull in tons of air. Also keep in mind that your truck is tuned to run using fairly warm air (makes for better mileage). If you start dumping in cold air (from deleting the warming function in the throttle body, cold air/ram air intake, etc), the motor will generate more power, but it is at the cost of mileage, especially in the winter.

In my case, I modified my air box. I did not do a "ram air" setup. I simply cut the funnel off of the filter box and then installed a K&N filter. I put my truck on a dyno and testing the before and after. I saw a 1 hp/10 ft-lbs gain with the modified air box. As for mileage, never really cared since I had done tons of other modifications at about the same time (so my mileage was going all over the place). Keep in mind that 10F of air temp change is good for 1% power change. So, if you can drop the air going into the motor by say 20F, you will gain 2% power. So, if you have one of the 300 hp 5.4L motors, that would be a gain of 6 hp. So, not a lot of gain since you are assuming that the motor is wide open. At normal cruising, you are only down at around say 100 hp, so, you are now making 102 hp. The big gains that people are seeing isn't so much from the cold air/ram air modifications but from finding an intake that is freer flowing and allowing the motor to not have to work as hard to get the same air into the motor.

 

[GAINMOB]

i have K&N intake and saw mpg's go up and throttle response...nothing drastic though the combination of the intake/exhuast is where i saw the most gains until i got my programmer...then it was maxed...efans will bump it up a notch so thats next