Custom Air Intake 2 mpg

dieselenthusiast · **Posted:** Sat May 05, 2007 7:45 pm

jcphoto20 wrote:

im having trouble believing it does any good at all.

but until i try it myself, ill trust you.

Jcphoto20, No worries, I take no offense to that. However, if you do fabricate something of this nature, just remember 4 things.
1. Bring as much fresh cool air into the factory air box as you can in the most direct route without jeopardizing lots of dust or moisture. The more twists and turns in the inlet tube means more restriction and decreases the ram air effect.
2. Use a inlet tube that will not absorb heat. And do not locate the inlet tube next to hot engine or radiator parts.
3. Upgrade to an Amsoil Filter. Air will only flow as fast as the air filter will allow it to flow. Amsoil flows 98% efficiency at 15 micron. And it has much more surface area verses the factory air filter to help deliver more air.
4. Utilize your factory air box. DO NOT use open or shielded type air filters that are exposed to the hot engine air. Tests have proven that an air inlet similar to what I have installed outperforms a shielded type inlet. The cost difference can be $200 dollars or more in savings.

jcphoto20 · **Joined:** Sun Nov 19, 2006 1:36 am **Posts:** 507

[quote="dieselenthusiast"] I don’t know any stock Liberty’s that are reporting 24 mpg. Based on this observation and the fact that I was only averaging 19.8 - 21.7 before the install[/quote]

sounds like you are getting the same mileage with a diesel that i get with a 3.7 and a "warm-air" intake.

upper 19s driving up and down the mountains and 24-25 hwy loop.

dieselenthusiast · **Posted:** Sun May 06, 2007 3:54 am

jcphoto20 wrote:

dieselenthusiast wrote:

I don’t know any stock Liberty’s that are reporting 24 mpg. Based on this observation and the fact that I was only averaging 19.8 - 21.7 before the install

sounds like you are getting the same mileage with a diesel that i get with a 3.7 and a "warm-air" intake.

upper 19s driving up and down the mountains and 24-25 hwy loop.

I’m not driving a CRD, I’m driving a 2007, 3.7L gasoline. So if I understand you correctly, you are also getting 24-25 mpg with your 3.7L, correct? So why do you have a hard time believing that I’m getting the same results as you? What type of "warm air" intake do you have?

jcphoto20 · **Joined:** Sun Nov 19, 2006 1:36 am **Posts:** 507

ah, my mistake, yur name throws me off.

so you are getting the same mileage as me with a cold intake and a 5 speed tranny with a taller final drive ratio as i am with a warm air intake and 4speed and 3.73s?

no i dont find it hard at all to believe that. its pretty easy to get good mileage out of a liberty mainly on the way you drive. you still have a couple more mpgs in there you can get by doing a few things to yours.

sorry , missed your question, i have one of those cheap cone things you shouldnt use in the dirt, just sittin in the bottom half of the stock airbox. but i think the last time i went off road was a couple years ago, so it doesnt really matter. looking back on it, i should have just left it the way it was, with the stock filter thats the same as a grand cherokee with a hemi from what i hear.

dieselenthusiast · **Posted:** Sun May 06, 2007 4:06 am

jcphoto20 wrote:

ah, my mistake, yur name throws me off.

so you are getting the same mileage as me with a cold intake and a 5 speed tranny with a taller final drive ratio as i am with a warm air intake and 4speed and 3.73s?

no i dont find it hard at all to believe that. its pretty easy to get good mileage out of a liberty mainly on the way you drive. you still have a couple more mpgs in there you can get by doing a few things to yours.

I did have a CRD, I traded it in for a 3.7 gasoline. What kind of air intake do you have?

jcphoto20 · **Joined:** Sun Nov 19, 2006 1:36 am **Posts:** 507

was reediting where i missed yur question as you responded, no worries

dieselenthusiast · **Posted:** Sun May 06, 2007 4:17 am

jcphoto20 wrote:

you still have a couple more mpgs in there you can get by doing a few things to yours.

What other suggestions do you have to increase mileage? Keep in mind that I have an automatic transmission and the 3.73 rear end.

jcphoto20 · **Joined:** Sun Nov 19, 2006 1:36 am **Posts:** 507

i thought all the new ones had 3.55 or taller. cool.

wrap your exhaust system! that will be your most noticable improvement if you have already changed to high quality synthetics front to rear. when i changed my fluids, there was a big difference in how quickly it gained speed when coasting down a hill, i drive the same road all the time, very rarely exceed any speed limits.

weight reduction, stuff in the gas, magnets on the fuel line (i used the ones from an electric R/C motor, i used to race them), exterior air flow improvements-i havent started mine yet on the jeep, have done some on my fullsize car with the better weather. i get better mileage in it, and its got a v8 and 160k. taping up the lower grill on it felt the same as changing to all synthetic in the jeep, coasts down hills noticeably faster, used to engine brake and maintain speed, now increases. next will be a panel i will use to smooth the airflow under the front past the engine compartment.

ive seen a little improvement with each thing ive done. and cant wait for the big cherry on top when i throw the aeroturbines on them.

dieselenthusiast · **Posted:** Mon May 07, 2007 10:38 pm

I got a question. I added a second air inlet in addition to my first. This time I can feel the difference and hear the difference. Here’s my question. When I accelerate hard you can hear a whining type sound, almost sounds like a fan blower or something, once it shifts into OD then the whining sound suddenly dissipates. The increased air flow provides much better throttle response and the motor sounds a little hyped up. I’m very happy with the upgrade. It’s like driving a whole new Jeep. Looks like mileage gains were about the same as with the first inlet, perhaps a little better. It’s hard to say as wind was a big factor today. I got 25.4 mpg running 60 mph with the wind to my back and 22.8 driving back home into the wind. What do you guys think the noise is? I’m not concerned, it runs good and has no check engine lights. I’m just curious as it seems funny that more air can make such a major difference in engine sound.

Phadeout · **Posted:** Tue May 08, 2007 1:20 pm

When I went from a stock Throttle Body and Airbox on my Ram (see sig), to a Fastman TB and K&N intake tube with a Big Mouth Filter (8" by 6" with a second inverted cone in the front, tonnes of air flow!) - the sound was different as well.

Before it was very quite, but after all that, you could hear the air rushing into the intake, especially if you went WOT. At highway speeds though, it sounded stock.

The extra air you have going into the intake may be causing some whistling too, that may only show up at certain RPMs.

dieselenthusiast · **Posted:** Tue May 08, 2007 10:16 pm

Phadeout wrote:

When I went from a stock Throttle Body and Airbox on my Ram (see sig), to a Fastman TB and K&N intake tube with a Big Mouth Filter (8" by 6" with a second inverted cone in the front, tonnes of air flow!) - the sound was different as well.

Before it was very quite, but after all that, you could hear the air rushing into the intake, especially if you went WOT. At highway speeds though, it sounded stock.

The extra air you have going into the intake may be causing some whistling too, that may only show up at certain RPMs.

Same with me, it's louder during acceleration but sounds stock at highway speeds. Did you notice a mileage increase? My mileage increase is hard to believe. Are you planning to upgrade your intake on the Liberty?

Phadeout · **Posted:** Wed May 09, 2007 1:19 am

I gained about 2mpg by doing intake/big mouth filter/throttle body/catless and straight thru magnaflow muffler.

Not bad considering it was only getting about 18, after all that I got 20... (highway). That's a big jump.

I do plan to do a number of mods to the liberty, stay tuned!

dieselenthusiast · **Posted:** Thu May 10, 2007 8:44 am

I've got the new custom air intake with the SECOND inlet photos on my BLOG. PLEASE check them out and give me some ideas. THanks, http://dieselenthusiast.blogspot.com/ or click on the WWW below in the signature.
Rhett

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

Looks good. I think you should spray paint it black to keep it from showing as easily and then it will look very good. Amazing how much the KJ likes additional cold air isn't it.

Phadeout · **Posted:** Thu May 10, 2007 12:49 pm

dieselenthusiast wrote:

I've got the new custom air intake with the SECOND inlet photos on my BLOG. PLEASE check them out and give me some ideas. THanks, http://dieselenthusiast.blogspot.com/ or click on the WWW below in the signature.
Rhett

I would add a "cone" type setup to the front of the intake tubes. This will act more like a scoop, and should make a big difference at highway speeds.

I will be doing this same mod... Nice to see someone else try it first though :wink:

jcphoto20 · **Joined:** Sun Nov 19, 2006 1:36 am **Posts:** 507

dieselenthusiast, am i correct in assuming you are only using the onboard computer when you are quoting mileage improvements at 73mph?

the computer only goes by throttle position, and if air is being rammed in there, then of course it will require a smaller throttle opening.

but then your computer is showing overrated figures since much more air than is expected is being put into it. this is corrected internally by the O2 sensors. the EVIC would only be accurate under pressurized circumstances if it were airflow based instead of the throttle position sensor.

what is your actual calculated mileage before/after your changes?

dieselenthusiast · **Posted:** Thu May 10, 2007 3:43 pm

jcphoto20 wrote:

dieselenthusiast, am i correct in assuming you are only using the onboard computer when you are quoting mileage improvements at 73mph?

the computer only goes by throttle position, and if air is being rammed in there, then of course it will require a smaller throttle opening.

but then your computer is showing overrated figures since much more air than is expected is being put into it. this is corrected internally by the O2 sensors. the EVIC would only be accurate under pressurized circumstances if it were airflow based instead of the throttle position sensor.

what is your actual calculated mileage before/after your changes?

Surprisingly the EVIC is pretty accurate. I always use a hand calculator to figure mileage. In Spring the wind is always a major factory, so mileage gains have been much harder to follow as it may differ day to day. Most of my driving in Missouri has been averaging speeds between 60 - 70 and occasionally having to slow down to go through small towns. It’s not like Wyoming or New Mexico, where there are miles and miles of straight highway for a more accurate reading. In another words, I prefer to run a vehicle at least 3oo miles before stopping and calculating mileage for a more accurate overall reading. There is no doubt that wind and running the A/C are major factors when recording mileage gains. However, based on the hand calculations and the miles on the tank before having to fill up, I’m estimating an average of 2 mpg increase in mileage before and after the install. As far as power and responsiveness, there is no doubt that you can feel it. Nothing major of course, but you can tell the KJ is getting more air. KYLiberty and a few others can verify that there is a mileage increase by feeding the KJ more cool air.

frankblack · **Joined:** Tue Jul 03, 2007 11:11 am **Posts:** 16

I stacked three intake tubes from the stock air box through the grill similar to what you have done...got rid of the K&N and switched to an Amsoil filter. I have also slowed down quite a bit and am consistently getting 23.5 + mpg's....I used to get 18 mpg....this is allowing me to eliminate 1 fillup per month....thanks!

any updates since you first posted your custom air intake system

frankblack · **Joined:** Tue Jul 03, 2007 11:11 am **Posts:** 16

I stacked three intake tubes from the stock air box through the grill similar to what you have done...got rid of the K&N and switched to an Amsoil filter. I have also slowed down quite a bit and am consistently getting 23.5 + mpg's....I used to get 18 mpg....this is allowing me to eliminate 1 fillup per month....thanks!

any updates since you first posted your custom air intake system?

dieselenthusiast · **Posted:** Tue Jul 10, 2007 1:43 pm

frankblack wrote:

I stacked three intake tubes from the stock air box through the grill similar to what you have done...got rid of the K&N and switched to an Amsoil filter. I have also slowed down quite a bit and am consistently getting 23.5 + mpg's....I used to get 18 mpg....this is allowing me to eliminate 1 fillup per month....thanks!

any updates since you first posted your custom air intake system?

Excellent news. Do you have any pictures to post? We moved from Missouri to Ulysses, Kansas which is near the Colorado Border. My wife drove with the A/C running and she averaged 23 miles per gallon the entire trip. We climbed elevation starting in Missouri at 1,324 feet and slowly climbed to 3,057 feet in Ulysses. Can you feel any power difference? I would like to do something a little more clean looking and perfect a few things on my air intake. I really enjoyed doing it and the cost was minimal for parts. The fuel savings are nice and will add up over time. More importantly I feel like the engine is more efficient.

Custom Air Intake 2 mpg

Who is online