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-   -   Cold Air Intake? (http://www.wranglerforum.com/f210/cold-air-intake-52394.html)

Kodysteeler43 06-06-2010 04:47 PM

Cold Air Intake?
 
Im looking for a cold air intake so my baby can breath. im looking at the Rugged Ridge intake because its cheap. am i wrong or is it okay to go with a cheaper intake because any aftermarket intake will be better than stock? also, is this intake a waste of money? should i save up and go with a more expensive intake?

Performance Cold Air Intakes - JCWhitney

jskinn27 06-06-2010 05:11 PM

i was contemplating on getting a cold air intake as well. i was talking to my buddy whose building his 47 willy up and he told me it will add hP and torque possibly improve mpg a bit, but it would be best to put money towards body armor (skid plates, rocker sliders ect) so if you do a good amount of off roading, you should armor up. there are also other ways to make her breathe better. headers, exhaust ect

ratuna 06-06-2010 05:15 PM

waste of $ you wont notice any improvements in anything. The stock setup breathes just fine for the Jeep. Save your $ and get anything besides that. Except an intake spacer, thats an even bigger waste of $

Jerry Bransford 06-06-2010 05:33 PM

While this may seem impossible to believe, it's true that the TJ's air intake is as free breathing as any other aftermarket air intake system out there. Not all air intake systems are free breathing, many like the Mustang 5.0L have a restrictive air intake, but the TJ's can definitely provide more air than the engine is capable of consuming at wide-open throttle and redline rpms.

That is straight from Jeep engineering, plus I verified it during a conversation a few years ago with senior Jeep engineer Jim Repp. Jim Repp, by the way, is the "father" of the Jeep Rubicon. They purposely designed it to have no restrictions. So save your $$$, you won't notice anything with an aftermarket air intake system unless you are suceptible to the placebo effect. :)

Kodysteeler43 06-06-2010 05:38 PM

Jerry-
does the exhaust have any effect? is it worth the money to buy an exhaust or is it the same as the intake?

Jerry Bransford 06-06-2010 06:05 PM

It's pretty much the same story with the exaust Kody as the factory installs headers onto the TJ already. The TJ does not use the more restrictive exhaust manifold that used to come on Jeep engines. :)

AzTJ 06-06-2010 06:16 PM

The only reason to get a "cold air" kit is if you get tube fenders that remove the factory air box mounting. :wavey:

Jma20a 06-06-2010 06:28 PM

a CAI will give you better throttle response and will give you 1 - 2 more MPG and 4-6 HP, and a louder sound. and a catback will do the same

dbrooks 06-06-2010 06:54 PM

Quote:

Originally Posted by Jma20a (Post 646158)
a CAI will give you better throttle response and will give you 1 - 2 more MPG and 4-6 HP, and a louder sound. and a catback will do the same

x2 this is true right here! :D

overall, its not a waste, but there are much better things you could buy for your rig.

burton160w 06-06-2010 07:06 PM

I have a CAI on mine that came installed when I bought it. It's not going to give you any HP increase, I would have to see some dyno tests for that one. Throttle response is also a myth, what would it be doing to increase throttle response? Finally, as far sounds go, it does give it a different sound, a sound that includes an annoying whistle at about 2k-3k RPMs, but a sound that definitely grew on me. The best reason why I would get one and why I do like mine is how it cleans up the engine bay. My K&N relocates the filter from running across the middle to running across the back so it does make it easier to work on your engine and I really do like that fact.

http://image.4wdandsportutility.com/..._tj+engine.jpg
http://sphotos.ak.fbcdn.net/hphotos-..._7562498_n.jpg

ratuna 06-06-2010 07:25 PM

Any HP gains would be hard to notice on a Dyno even if you ran it stock then changed intakes and ran it again on the same dyno. There are so many factors involved i.e ambient temp, engine temp, humidity. If anything changed while you were doing the swap your results would be skewed slightly making a 1-2 hp gain almost impossible to detect.

But everyone has their own opinions including me, i would never put one on my Jeep. But if you really want one and think it'll help go for it.

Kodysteeler43 06-06-2010 07:47 PM

I have a 2.5l and am only in high school. So i dont have too much money. im looking for a fairly cheap way to increase some power because of the smaller engine. So any ideas on how to pull that extra power outta my little engine?
-thanks

Jma20a 06-06-2010 08:18 PM

Quote:

Originally Posted by burton160w (Post 646176)
Throttle response is also a myth, what would it be doing to increase throttle response

if you take a look at your pictures you can see how the factory has the flex pipe, when the throttle body opens up it has a easier time to suck air into it without the flex pipe, that gives it the better throttle response.

ratuna 06-06-2010 08:39 PM

Quote:

Originally Posted by Kodysteeler43 (Post 646205)
I have a 2.5l and am only in high school. So i dont have too much money. im looking for a fairly cheap way to increase some power because of the smaller engine. So any ideas on how to pull that extra power outta my little engine?
-thanks

There is no replacement for displacement, this old saying holds true in this instance. Nothing short of swapping engines is going to give you enough of an increase in power to be worth the $ spent. Even the engine swap probably wouldn't be worth it, best bet would be save your $ and trade in the Jeep for a 6cyl.

stevens243 06-06-2010 09:22 PM

CAI's are a waste of money, time and labor (whether yours or a shop jock's).

Not only will they do NOTHING for your performance but they do not (not!) filter air as well as a stock paper filter.

Gonna go out and get dirty and drive some dusty trails, the CAI filter will fail you and you'll need additional money spent on other crap to keep the top end clean.

KawiTJ 06-06-2010 09:40 PM

Quote:

Originally Posted by stevens243 (Post 646294)
CAI's are a waste of money, time and labor (whether yours or a shop jock's).

Not only will they do NOTHING for your performance but they do not (not!) filter air as well as a stock paper filter.

Gonna go out and get dirty and drive some dusty trails, the CAI filter will fail you and you'll need additional money spent on other crap to keep the top end clean.

im wishing i left mine stock, my intake tube shows signs of alot of muddy water... seeing that i cut my intake tube i cant do much... maby ill make something to use the stock box again

stevens243 06-06-2010 09:46 PM

Quote:

Originally Posted by KawiTJ (Post 646311)
im wishing i left mine stock, my intake tube shows signs of alot of muddy water... seeing that i cut my intake tube i cant do much... maby ill make something to use the stock box again

I USED to have a K&N (junk) on mine. I posted a couple of "want to buys" for a stock intake and found one. 25 bucks. Back to stock!

burton160w 06-07-2010 12:31 AM

Quote:

if you take a look at your pictures you can see how the factory has the flex pipe, when the throttle body opens up it has a easier time to suck air into it without the flex pipe, that gives it the better throttle response.
I have a hard time believing that flex pipe restricts air enough to hinder throttle response.

Quote:

Not only will they do NOTHING for your performance but they do not (not!) filter air as well as a stock paper filter.
Filter-wise, it does fine in dust and dirt, but it doesn't filter out small quantities of water like the stock does because it's an open air system. There are off-roaders who will attest that CAI would be terrible on the trail because it sucks water right into the throttle body. I mud in the dusty sands of the Pine Barrens and when I did a complete TB clean, there wasn't really that much dirt or dust trapped as opposed to other horror stories I've heard. I can also wash the filter out regularly which is nicer then having to keep paying for new stock filters. So overall for dirt and dust I'll take the CAI system, but if you don't run a snorkel and your playing in the puddles, watch out because the open-air system can really suck in water and damage your engine or hydrolock you.

Pontiackid87 06-07-2010 01:05 AM

I have an edge CAI on my jeep and its comming off as soon as i find the time to do it. Mine is coupled with the edge TB but i dont really see a need to remove that yet. Reason why i want to remove my CAI is going through water and puddels is not good for a CAI system. Most time's on your avrage streer ricer there CAI is ran down into the fender where little to no water can get to it. It looks a bit diffrent in the jeep though because its more of a ram air intake than a cold air and my last time off roading it seemed like a lot of water was able to get to it.

Heres some pics of it for you.. Please excuse the dirty engine bay havent been able to clean it since my last off road session
http://i208.photobucket.com/albums/b...2/HPIM0366.jpg
http://i208.photobucket.com/albums/b...2/HPIM0364.jpg

Kodysteeler43 06-07-2010 08:20 AM

Quick question.
I understand that the stock tube and/or intake was built for good breathing, but how cant a CAI system do better? I mean, stock has a box with a little opening. A CAI is all open. I believe the tube on stock is great but the box?
Any ideas?

n8smitty 06-07-2010 09:36 AM

I lost about 2 mpg when I lifted my Jeep. I put the Banks CAI on mine a few months ago and I have gotten my 2 mpg back. So to me it was worth it because I get my original mpg. It is a little louder and the throttle response does seem to be better. I like it and to me it was worth the money if I can get an extra round trip to work every tank. It's all a matter of opinion and application. Some like them and some don't. Some think they make a difference (although small) and some want it to give them 30 mpg and 500 hp.

cntrybmpkn86 06-07-2010 09:53 AM

The Banks Monster Exhaust is a huge power gainer with the cold air intakes bigger throttle bodies and throttle body spacer. If you put them all on at the same time you will see a huge difference but if you put them on one at a time you will not see much gain but it does help tremendous. I have it all and would not take it off for anything.

TJfun 06-07-2010 10:19 AM

Quote:

Originally Posted by Kodysteeler43 (Post 646095)
Im looking for a cold air intake so my baby can breath. im looking at the Rugged Ridge intake because its cheap. am i wrong or is it okay to go with a cheaper intake because any aftermarket intake will be better than stock? also, is this intake a waste of money? should i save up and go with a more expensive intake?

Performance Cold Air Intakes - JCWhitney

There are some technical things to keep in mind when fumbling around with engine parts that a lot of people, including myself, overlook. Things like the difference between a carburetor and fuel injection, O2 sensors and how many you have, gas milage jumping around. These are controlled by the computer.

Because the computer controls how much fuel to give the motor by using the O2 sensors, blasting the motor with air would only lean it out. The computer would sense this then try to compensate in its stock form settings and richen it up some =less MPG. Because it is fuel injected the computer will only allow so much air and fuel to mix anyway. This means you now have to manipulate the computer to want the extra air flow.

If you decided to do this then you would need that high flow air/fuel mixture to go out of the motor. Now you have to open up the exhaust to let it pass by getting a different exhaust set up. Be careful with opening it up too much because then you may loose H.P.

I built a 1968 Charger with a 413 and opened her up to breath. That worked great. I have an '03 Rubicon and tried to do the same with the Banks and I felt no difference. I took off my stock exhaust and put a 2.5 straight pipe dumped at the pumpkin, lost power and MPG. Then someone told me the facts as to why I had so many troubles. It is all controlled by the computer.

I have to agree with some of the fellas and say save your $$ until your are ready to build the motor from head to toe:)

06TJinVA 06-07-2010 10:23 AM

I installed the AEM Brute Force Intake and it works great. It came with the throttle body spacer for my TJ. It installed easy and I can really tell a difference on hills and such as I am driving down the highway. But if you start with the CAI you might as well spend money on exhaust as well. A better breathing engine is a better running one.

rrich 06-07-2010 12:52 PM

Isn't it funny when it comes to this subject logic and reason go away.

You decide --

At 4000 RPM with a 4.0 Liter engine where cylinders "gulp" air every other revolution, it "gulps" 8000 Liters per minute. (4000*4.0)/2

Think of 8000 liters of coke! That's 133 Liters each second!

Now look at the tiny hole in the stock airbox where the air gets in - all of the air must pass through it. Picture cramming 8000 liters through that small hole. (But it doesn't restrict?)

When you jog you don't use even close to that much air - picture yourself trying to jog breathing through that little airhorn. Better yet, pull the little airhorn off and try it!

That's if the air was to flow smoothly, but an engine's inlet air isn't smooth. It pulses much the same as the exhaust (and like we breathe.) Those "gulp" peaks are much larger than the steady state flow. That's why hi rise manifolds work - pulses! The intake. like the exhaust, must be designed to handle those peaks.


The "engineer" that claimed the intake is not restrictive - I wonder where he'd be working now if he was honest and told the truth -- "Yes, Chrysler screwed up - it's very restrictive."
How long after a public statement like that got around do you think till he's fired? 10 days? 2 weeks?

Try it yourself - make a public statement that your company is lying about it's products - how long will you last? (Don't, it's too hard to find a job lately.)

To try it for yourself cheap. Disconnect the tube from the Throttle body to the airbox. Leave it open and take it for a ride. You'll prove it to yourself whether it makes a difference by getting rid of the airbox.

If you are uncomfortable with it drawing in unfiltered air for the ride, slip a cheapie cone filter on the tube - AutoChina sells them.

The cold aspect - yes, cold air is denser, therefore more oxygen will be ingested. It might make a slight difference - slight being .01 seconds in a 1/4 mile drag race. Running on a day when the Barometric pressure is up would make more difference. But when racing, that .01 second can make a big difference. Remember that next time you are in the starting line.

Underhood temps when driving are not that much hotter than outside air IF your cooling system is working right - yes I've checked it with a pyrometer. Cooling system also includes the airflow around the engine.

Yes, it does get hotter when you stop - but do you need the extra power when stopped? Think about it!

Simple and cheap. Cut the plastic tube a few inches from the throttle body and fit a filter on the end.
I used to like K&N, but once it let me down - dirt got in - no more K&N for me.
Trueflow makes a good foam filter.

Even the Trueflow is slightly restrictive, but you need something to keep the dirt out.

Yes, when and if more air gets in, the computer adds more fuel to keep the mixture right. The computer's adaptive memory soon learns how much that "extra" will be, so the mixture will stay correct.
But - the new total amount of air and fuel can now be utilized in a full throttle condition - thus slightly more power.
Mileage will probably drop a little, as you'll be flooring it more often - just for fun. Pulling up hills you'll definitely notice a difference.

The throttle body spacers - especially the ones with the internal swirls or ridges - they work on carburetors where the fuel is already mixed with the air - AND IF the carb is large enough to overcome the restriction of the extra turbulence - the swirling helps keep the fuel atomized. But our Jeep Fuel injections don't have fuel up there, it's added right by the intake valve. The spacer is only swirling air, not something you want. Swirling the air in the TB only adds turbulence - restriction - the very thing you are trying to avoid with a better intake filtration system. Self defeating.

Of course there will be "experts" that argue - that's the nature of the forum.

But try it yourself! Now you know how without a dyno.

mistert 06-07-2010 01:08 PM

open up that breather?
 
1 Attachment(s)
I believe Jerry is right, it's not really worth the money for the very small amount of difference and, unless you utilize a very free-flow or non-restrictive exhaust, all athe air in the world will do very little. I'll also have to agree somewhat with rrich that it does help some by allowing the engine to be more efficient and responsive. I open up all my vehicles, intake and exhaust and recognize an immediate improvement in response however I'll add I did not realize any change in my TJ milage or performance.

greene91 06-07-2010 01:58 PM

nice post, rrich. I like a good explanation in a post like that.

Jerry Bransford 06-07-2010 02:16 PM

One thing rrich leaves out is that it's not pulling 4000 liters of air all at once as he points out then conveniently leaves out when he later jokes about how the air intake couldn't possibly allow that much volume of air in. Well, it does and it does so just fine.

And the Jeep engineer that assures us they designed the TJ's air intake to be 100% non-restrictive, Jim Repp, is not just any engineer. In fact, Jim is one of Jeep's most senior engineers, having been in Jeep's engineering group since the AMC days. Yes, he was designing CJs before the YJ, TJ, and JK were even someone's wet dream. Jim is also widely credited for having been the "Father of the Rubicon", it was his idea and his dream.

Personally, I will take Jim's word for what he says over anyone else's and he and I had several phone conversations on this (and a few others) very subject several years ago. And having had a TJ with all forms of air intakes including OE, K&N, TurboCity, and its present CAI (it came on the '04 Rubicon I just bought), I can say with personal experience that not a one of them made any difference in performance... at least none that I can detect with over 200K miles on two different TJs. Which goes right along with what Jim Repp says about the TJ's OE air intake design.

Finally, how did I come to have such conversations with Jim Repp? I was one of the first TJ owners back in 'early '96 and my 4.0L engine started developing a misfire that caused a series of misfire trouble codes. After nearly a year of asking in the various forums for help on it, Jim contacted me and asked him to call him. He had been assigned to figure out what the problem with that was hitting a lot of Jeeps & he just happened to find my posts about it. He ended up sending me a box of parts to try... clock spring, a complete set of fuel injectors and fuel injector wiring harness, PCM (engine computer), etc. and during my trials of installing those parts, we developed somewhat of a relationship. This was nearly two years before the Rubicon came out and he then started feeding me bits and pieces of Rubicon information to help kill some of the false rumors. We developed a pretty good relationship during that time.

Based on that relationship and Jim's explanation of how they came to design the TJ's air intake system as they did, most of which I no longer recall with much clarity, I'll just say that what he told me made sense and it makes a lot more sense than much of the above conjecture that isn't based on much other than what sounds right to one particular individual. :)

Jerry Bransford 06-07-2010 02:32 PM

P.S. (the edit timer ran out) How many of us run out engines at near redline for a minute to ever pull that 8,000 liters of air into the engine within that one minute timeline rrich talks about? :rofl:

rrich 06-07-2010 02:58 PM

"""""One thing rrich leaves out is that it's not pulling 4000 liters of air all at once as he points out then conveniently leaves out when he later jokes about how the air intake couldn't possibly allow that much volume of air in. Well, it does and it does so just fine."""""

Thanks for your response Jerry. That 4000 Liters is not all at once of course. And - It's 8000 liters of air, not 4000! The 4000 is engine RPM. If you want to see how much air that is at slow cruise 2000 RPM, simply divide that 8000 by 2.

Then, I also added how much air that means in one second (at 4000 RPM) - no tricks here - the 8000 a minute divided by 60. 133.33 Liters a second. Use a calculator.
8000/60 seconds.

The 4000 RPM figure was used for easy calculations. But if you want to know how much that is at say 2657 RPM, simply multiply the 4.0L * 2657RPM, then divide by 2. Use whatever speed you want. Not rocket science, far from it.

It obviously works as it is. But some folks are looking for a little extra. The stock airbox filters most of the dirt out, and it's a silencer. Those with other intakes have noticed the higher noise level. But many of those folks also want their exhaust loud, overshadowing any intake noise.

When you are straining up a hill you notice the difference more than at other times. You are usually running somewhere between 2500 and 4000 RPM on those hills. Less than that it's time to backshift to get back up on the power curve. That's when starving for air affects it the most - or giving it more air.

Try jogging with that tiny little airhorn over your mouth. If you can't breathe enough through it, how can your engine that needs lots more air?


Some will never believe logic - a few will try the suggestions and prove it to themselves, everyone else will just say "Huh?"


The air gets through, just not all of it, not as much as the engine "wants." If you were to measure the tube right after the box, you'd see a vacuum - caused by the restrictive box and tiny hole. A regular vacuum gauge probably won't give much indication, since a vacuum gauge is dampened and it reads the "average." But you can try it. ANY vacuum reading there shows a restriction upstream - basic physics 101. A manometer will show it clearly.

It's not just conjecture, it's fact. It's not what a guy that's worried about his job says. He's head, so he's got even more to lose. What would he do if one of his subordinates told the truth?

I can speak out - they can't fire me!

I also told how anybody can verify it for themselves - simple! Don't take my word for it try it yourself!

Can and will Chrysler fire anyone that tries it"

I already sold my stock in Chrysler, I was afraid your new prez would nationalize it like he did GM - where everyone with a retirement based on GM stock lost everything! He may still do it to your friend yet.


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