Hi everyone, I just have some questions about intakes as I am interested in getting one in the near future.
First off, I have a 2.5L TJ. I am not worried about the heat in my engine, but I am in upgrade mode right now and I want some extra performance for when I put some 32" tires on later. So I just wanted some feedback, like what is a good brand for a 2.5L TJ, is it worth it, can a complete newb install it? I have had my eye on the AEM Brute Force intake for some time now, but whenever I mention this to people they say AEM is for cars and K&N is more suited for trucks. All I need is a little clarification from you guys who know your stuff and perhaps some pointers.
I had an AEM Brute Force Air Intake on mine. Definately a noticable power difference. The only thing is that If you wheel in water, that thing becomes one big sponge. You will hydrolock in water. On street, your fine.
I'll go against those who say you'll notice a power difference, unless you're suceptible to the placebo effect.
And throttle body spacers are literally useless under the type of throttle body a TJ has since only air passes through it... no fuel whatsoever. Making the air path longer does nothing. Spacers are great under carburetors and throttle body injection engines, just not under a TJ's TB since the TJ's fuel is injected directly into the combustion chamber, well below the throttle body.
Well I am kind of turned off by the whole idea of a new intake after reading around for a little bit. What else could I do to get more performance? Those performance chips just look like complete BS to me. Would a new K&N filter serve a useful purpose?
Yes, engine rebuilders LOVE people who run them since they allow more silica and grime past them. I ran one for a while after installing a belt-driven air compressor that required the OE filter box to be removed. It took two prefilters (an Outerwears and a foam Unifilter) over the top of the K&N POS to keep the gritty desert sand and silica out of my engine since it was getting past the K&N. K&N air filters are only ok for the street, not in dusty offroad conditions. And if you say that some of the desert racers run K&Ns, let's not forget that those guys rebuild their engines all the time anyway.
You can bolt on whatever you want to their habitat, but I don't think you're going to be able to squeeze enough out of those four squirrels to run 32s comfortably.
Gears and/or more cubic inches are the answer for on-road performance. I suppose a 4:1 would be OK for off-road purposes.
You can bolt on whatever you want to their habitat, but I don't think you're going to be able to squeeze enough out of those four squirrels to run 32s comfortably.
Gears and/or more cubic inches are the answer for on-road performance. I suppose a 4:1 would be OK for off-road purposes.
Including all parts and labor, it's pretty close to $1100-1200 to regear both axles. While it's not cheap, it's worth paying someone to do it for you as the process is very exacting, tedious, and if not done perfectly means the new gears will be toast in short order.
regearing sounds really great and I have heard of fellow '4 bangers' using 33" tires no problem once regeared. Unfortunately, I can't afford it, I just need something to to compensate so that I get equal performance as my 31" with 32x11.5 tires. I would love to add a body lift, regear, and I would have a fully functioning 4 banger sitting on 33's, but I just don't make that much money as I am still in high school.
When re gearing, does the gear ratio have to correspond with your tire size, or could you get say a 4.88 ratio with 31" tires to future proof it in case of a tire upgrade?
You could certainly regear to 4.88 with 31" tires but your engine RPMs would be excessively high so that you'd be wanting to 33" tires on there asap to get the RPMs back down to where they should be.
K&N is the same whether it be stock airbox or CAI, just stick with the stock filter, if it gets dirty pay the $5 for a new one, you can buy 10 paper filters for the price of one K&N. my jeep is 2 years old and im only on my second filter.
For actually filtering the air, a K&N is right at the bottom of the list. The below photo is what I had to do to my K&N to get its filtration to the point my air intake wasn't coated in crud. I no longer run a K&N for that reason.
The two prefilters (an Outerwears and a foam Unifilter) on top of the K&N are slid back so you can see them individually.
The latest issue of JP magazine rates a bunch of air intakes and measures performance.
I didn't read it too closely but what I basically got out of the article was this: for around four hundred bucks I can get 10 more pounds of torque and 10 more horsepower. Oh, and a dirtier engine.
The latest issue of JP magazine rates a bunch of air intakes and measures performance.
I didn't read it too closely but what I basically got out of the article was this: for around four hundred bucks I can get 10 more pounds of torque and 10 more horsepower. Oh, and a dirtier engine.
No magazine, especially Jp magazine, ever tested a product that advertised in their magazine that they didn't like. Jp is as guilty of that as any magazine I've ever read. They're there to push products which brings in advertising dollars. And it is advertising dollars they are paid with, subscriptions and sales of magazines is secondary income for them. They just need to sell magazines so they point to their advertisers how many readers they have. Like newspapers, the income received from individual sales to their readership is very little when compared to what they make from the advertisers.
Unless you get the air from out of the engine compartment whether you use the stock air box or the cold air intake, the air temp will be the same. As far as getting more air in, you will need a turbo or super charger fot that. The engine can suck all the air it needs through the stock box, if it wasn't getting enough you would be able to tell.
The air box on the TJ is a good design. If ever end deep in water you will be screwed running on of those big cone filters.
I have a 2.5L with the 3 speed auto on 33"s and it does just fine...
It is my DD and I get in the upper teens (mpg) city driving to school, and work.
Let me know if I'm wrong but 2.5Ls all came with 4.10 gearing...
If it is your DD and you do any highway driving at all personally I wouldnt regear it...
My Jeep does just fine, and is in great shape... Personally I would listen to someone who actually has a 4 cyl. and drives it everyday than someone with a 6cyl who could only have it as a toy.
Save your money and get some light wheels to loose rotational mass instead.
I agree with looking for advice from fellow 4cyl owners... I too have the 2.5 auto with 33's, but I don't see why you adviced against re-gearing if it's his DD and he runs on the highway? I have 3.73's, but I'm heavily looking into a friend's D30/35 set with 4.56's... he's offering me a good deal for both axle, complete, so I'm really considering it.
I think for DD use, I will enjoy it that much more with 4.56's.
My dad had a cold air intake on his XJ and was failed (visual check) at his last smog check. The tech told him that no modifications are permitted to the air intake system. Is this a bunch of BS or a California thing? At my last smog check I was told by the tech that he's supposed to fail me (visual check) for my over sized tires.
If you're just a street driver, re-gear your axles for the larger tires to maintain your stock power and gas mileage. For trails, D30's and D35C's (actually a Chrysler axle not a Dana) are junk. If you're gonna run any trails or heavy use get D44's or better yet D60's. You can spend 3K building a D30 but you'll always be in the shop for repairs. I went through 3 D30 front axles before I got instructed on the error of my ways. Just my 2 cents.
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