Custom Air Intake 2 mpg

dieselenthusiast · **Posted:** Sun Apr 29, 2007 12:31 am

My description and pictures can be viewed on my blog. Click on the www in my signature or click on my link. http://dieselenthusiast.blogspot.com/

AZScout · **Posted:** Sun Apr 29, 2007 2:52 am

Nice job, and very interesting. Are you doing this with a CRD airbox or a gasser airbox?

dieselenthusiast · **Posted:** Sun Apr 29, 2007 3:27 am

AZScout wrote:

Nice job, and very interesting. Are you doing this with a CRD airbox or a gasser airbox?

I traded off my CRD a few months ago for the 2007 gasser. I’m using the factory 3.7L air box but added an additional inlet for more cool air. I wasn’t overly impressed with the factory air inlet. The more I thought about it, the more it bugged me. So I spent the last few weeks walking through hardware stores, talking to others on this forum, and trying to come up with the best way to bring more cool air to the motor. I wanted to see if the engine was really starving for more cool air, so I used the “Ram Air Effect” as seen in my pictures. My wife and I couldn’t believe it, she said, “you mean putting that little tube on made that big of a difference?” To be honest, I was shocked! :shock:

I thought I might see a .5 mpg gain and was hoping for 1 mpg gain. But a solid 2 mpg increase! :shock:

All for under $5.00 bones! :shock:

I hope someone copies what I did or reports similar gains by coming up with their own modification. I have a feeling that NOBODY is going to believe me. :cry:

And I don’t know any L.O.S.T. members locally who can verify my findings. :cry:

LostRenegade · **Posted:** Sun Apr 29, 2007 7:20 am

What did you use for the tubing?

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

The Libby actually responds to colder air quite well. I've been saying it for years. Everybody always says I'm full of BS when I tell them my actual increases at Interstate speeds, so I just say over 15%. Of course you need to consider that the outer edges of the scoop are 2"X25", funneling into a 21.5"X1" opening that blows through a 5"X4" opening right on top of the cone for the FIPK. StreetKJ can also verify that colder air really helps it. Here's a link to his $4 cold air intake mod.
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?t=11748

tommudd · **Posted:** Sun Apr 29, 2007 11:45 am

I have been experimenting also with different ways to get more air in, right now have the stock air box back on with the air intake that went up towards the hood off and 6 inch flexible dryer vent hose from the box up through to the front of the grill. you do have to "smash" it down some to about one and a half inches by of course 6 inches but then the original is about that same size. I have only ran it about 250 miles but seems to help a little. Nope no pictures yet.

Phadeout · **Posted:** Sun Apr 29, 2007 1:01 pm

dieselenthusiast wrote:

My description and pictures can be viewed on my blog. Click on the www in my signature or click on my link. http://dieselenthusiast.blogspot.com/

Looking at the pictures, did you "stuff" the original inlet hole and are now running strictly on the inlet tube, or is the original hole still open?

dieselenthusiast · **Posted:** Sun Apr 29, 2007 8:21 pm

LostRenegade wrote:

What did you use for the tubing?

1.5” x 16” plastic tubing that came from a Kitchen End Outlet Drain Assembly Kit from Wal-Mart, under $5.00 dollars. At first I was a little concerned that using a 1.5” inlet tube wasn’t going to be large enough. But I wanted to use it anyway as it was the best method that I found to deliver ram air to the box in the most direct route. I plan on making some type of scoop for the inlet to catch more air. I found a second location that I thought would work in addition to my first. The second location is running the same size of tube through the plastic square looking piece that runs along the side of the headlight housing. There is a hole that is exposed to the front of the grill at the end of the plastic housing. I would cut away the rubber deflector to send fresh cool air down the tube and directly to the factory snorkel by cutting with the hole saw again.

dieselenthusiast · **Posted:** Sun Apr 29, 2007 8:39 pm

KY Liberty wrote:

The Libby actually responds to colder air quite well. I've been saying it for years. Everybody always says I'm full of BS when I tell them my actual increases at Interstate speeds, so I just say over 15%. Of course you need to consider that the outer edges of the scoop are 2"X25", funneling into a 21.5"X1" opening that blows through a 5"X4" opening right on top of the cone for the FIPK. StreetKJ can also verify that colder air really helps it. Here's a link to his $4 cold air intake mod.
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?t=11748

Oh yes, I remember seeing StreetKJ's modification. :lol:

I laughed because I considered using the downspout before I saw that he had used it. I like the downspout idea because the square end was flexible enough to squeeze through the tight opening to the grill. His inlet is much larger than mine, so I know he is scooping up more cool air. I like the cleanliness and direct route of my installation, but I do plan on adding a second inlet and modifying some sort of scoop to the inlets in hopes to funnel more air into the intake tube. Your right KY Liberty, more air does make a BIG difference, more so than what I had ever expected. Now that more of us are reporting similar results, hopefully more people will start believing us. The is probably the best modification for the cheapest cost.

dieselenthusiast · **Posted:** Sun Apr 29, 2007 8:50 pm

Phadeout wrote:

dieselenthusiast wrote:

My description and pictures can be viewed on my blog. Click on the www in my signature or click on my link. http://dieselenthusiast.blogspot.com/

Looking at the pictures, did you "stuff" the original inlet hole and are now running strictly on the inlet tube, or is the original hole still open?

I’m still using the factory inlet tube in addition to my custom install. In the picture I took the factory inlet off so I could measure the amount of tubing needed for my second inlet that will run from the grill straight into the factory inlet tube. I hope to have it installed sometime soon.

kolesy · **Posted:** Mon Apr 30, 2007 3:05 pm

Did you do this mod at the same time you put the AMS oil air filter in too? I am wondering if the new air filter aided in your gains? That is wild wild though that it bumped up your mpg that much!! Good stuff! And thanks for sharing!

dieselenthusiast · **Posted:** Mon Apr 30, 2007 11:16 pm

kolesy wrote:

Did you do this mod at the same time you put the AMS oil air filter in too? I am wondering if the new air filter aided in your gains? That is wild wild though that it bumped up your mpg that much!! Good stuff! And thanks for sharing!

Yep, I installed the Amsoil Air Filter at the same time of the install. I don’t know the flow rate of the stock filter to compare to the Amsoil. But here is what Darby wrote:

DarbyWalters wrote, “I just received my new filter and immediately noticed some big differences. Althoght the filters have similar dimensions length and width, the number of pleats and size of pleats are different. If you unfolded the Amsoil filter media you would have 1,888 square inches of filtering media. If you unfolded the OEM filter media you would have 894 square inches of filtering media. That is 211% increase in filtering area with the AMSOIL air filter vs the OEM filter. Better media AND more filtering area has to be a plus. The stock filter has 67 pleats at 7/8" tall...the AMSOIL filter has 110 pleats at 9/8" tall.”

I do know that Amsoil flows 98% at 15 micron. So based upon Darby’s observation, I would say that the Amsoil air filter played a significant role in the increase of performance and mileage.

dieselenthusiast · **Posted:** Sat May 05, 2007 1:22 am

Good News! After doing some real world driving experimentation, I’m happy to report a gain of an additional 40 - 45 driving miles on a tank of fuel with the added air intake and Amsoil air filter. It sure felt good bypassing the normal fuel stop and continue driving where we would normally have to stop and fill up. I’m still showing somewhere between 1.9 mpg - 2.5 mpg increase. My driving speeds vary from 60 mph - 75 mph. I do start to see a drop off in mileage running at 73 mph. I’m eager to add my second inlet location to see if that helps increase or stabilize the mileage gains at 73 mph and other speeds as well. My inlet is pretty small (1.5”), so maybe an additional (1.5”) inlet will increase the amount of cold air entering into the air box.

Jeepjeepster · **Posted:** Sat May 05, 2007 11:58 am

You didnt happen to put this in right when it was warming up did you? Ive noticed a huge increase in mpg when its warmed up. It always taken me around 3/4 tank to get home and back to school but now it only takes around 1/2-5/8 of a tank since its been warming up.

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

The winter mix gas here causes me to lose a couple mpg. Of course, so does a dirty air filter or needing an oil change.

waddy whiteguts · **Posted:** Sat May 05, 2007 12:33 pm

Nice to see you getting better mileage but for your results to mean anything at all you should be compairing your results originally with stock box and dirty filter, then stock box with clean filter, then stock box with amsoil filter, lastly modified box with amsoil filter. You made a lot of changes at once to take any credit at all for the increased mileage. You might just have had a filthy old filter in there... not trying to be a richard or anything, I do think 2mpg is significant and a very good thing with our thirsty KJs

Looks like your tube should be pretty easy to cap off too for driving in water. Slick install.

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

im having trouble believing it does any good at all.

but until i try it myself, ill trust you.

dieselenthusiast · **Posted:** Sat May 05, 2007 6:10 pm

Jeepjeepster wrote:

You didnt happen to put this in right when it was warming up did you? Ive noticed a huge increase in mpg when its warmed up. It always taken me around 3/4 tank to get home and back to school but now it only takes around 1/2-5/8 of a tank since its been warming up.

Excellent observation! I did install the air intake and the Amsoil filter at the time of warmer weather. Before the install I was averaging (City/Highway) between 19.8 - 21.7 mpg in 70 degree temperatures. The next day, and after the install, and in the same temperatures, I jumped up to 24 mpg. The A/C does take a toll on the mpg dropping it down to 23 mpg.

dieselenthusiast · **Posted:** Sat May 05, 2007 6:49 pm

[quote="waddy whiteguts"]Nice to see you getting better mileage but for your results to mean anything at all you should be compairing your results originally with stock box and dirty filter, then stock box with clean filter, then stock box with amsoil filter, lastly modified box with amsoil filter. You made a lot of changes at once to take any credit at all for the increased mileage. You might just have had a filthy old filter in there... not trying to be a richard or anything, I do think 2mpg is significant and a very good thing with our thirsty KJs

Looks like your tube should be pretty easy to cap off too for driving in water. Slick install.[/quote

Good Point! Let me clarify. We just turned 3,000 miles on our Jeep today.

The factory air filter naturally was clean at the time of the Amsoil filter change. In a very short time I have driven the same 164 mile driving route before and after the install for comparison due to pre and post eye surgery appointments. 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, I have to conclude that the Amsoil air filter and ram air intake tube increased the amount of cold air being delivered to the motor. My intentions for the install had little to do with fuel economy. Trust me, I didn’t buy a Jeep for fuel economy. My intentions were curiosity and to increase performance. I was really curious if I could squeeze more power from the 3.7. I figured there might be some increase in fuel economy, but I didn’t realize it would be this dramatic. :shock:

Jeepjeepster · **Posted:** Sat May 05, 2007 6:56 pm

Need to take the Air Filter out on a rainy day and see what the mileage is.. :twisted:

Someone get back to me when they do that.. :lol:

Custom Air Intake 2 mpg

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