Airaid Or K&n Intake Air Filter Systems

[Keyav8r]

I'm looking at an aftermarket intake air filter system to (a) make room for a dual diaphragm brake booster and (b) clean up the look of the driver's side of the engine bay. I've seen photos of several members' MJs with Airaid and K&N intake systems and am thinking of going in that direction. But I haven't found a listing by either Airaid or K&N on a specific system for an 88 MJ 4.0 L Renix application.

If you have either of these systems on your MJ, could you post the part numbers you purchased and tell me about any modifications needed? Did you box it in and enlarge the opening through the radiator support for better cold air intake? Or, just hang it out there in the open and let pull air wherever?

Also, is there provision for the fresh air supply to the valve cover and a vacuum connection as on the stock airbox?

[COFFMAN]

Do ARB or Safari make one for the XJ/MJ ???

[Wrz]

Ive had the K&N on my 00 xj with the 4.0 ho and its not a bad setup but don't think its worth the $$, i recently installed an airaid intake on my comanche, pulled it off of a 95 xj,  all xj intakes should work fine, just need to adapt it to your current throttle body which is the fun part since its a renix,

 

After a few hours trying to make it work and no luck i came across this adapter, just ordered it tonight

http://www.spectreperformance.com/index.php/catalog/air-intake-components/accessories/throttle-body-adapter-87-90-jeep-4-0l-renix.html

 

Hope this helps, can't say how the airaids performance is since my mj is still in the build process

 

 

I'm looking at an aftermarket intake air filter system to (a) make room for a dual diaphragm brake booster and ( B) clean up the look of the driver's side of the engine bay. I've seen photos of several members' MJs with Airaid and K&N intake systems and am thinking of going in that direction. But I haven't found a listing by either Airaid or K&N on a specific system for an 88 MJ 4.0 L Renix application.
If you have either of these systems on your MJ, could you post the part numbers you purchased and tell me about any modifications needed? Did you box it in and enlarge the opening through the radiator support for better cold air intake? Or, just hang it out there in the open and let pull air wherever?
Also, is there provision for the fresh air supply to the valve cover and a vacuum connection as on the stock airbox?

[Automan2164]

 

 

http://shop.trailheadoffroad.ihostnetworks.com/productinfo.aspx?productid=XJCI91-01

 

Rob

[Biotex]

Just want to point out a couple of things to anyone thinking of a K&N style filter.

To provide air filtration you have to use a media of whatever micron size you want to filter down to. The smaller you go, the more restrictive the air flow becomes. A less restrictive filter such as a K&N comes with a price that you can't get away from. You see, you can't have it both ways. Adding oil to the filter gets around this , but again you have a trade off. The oil does a good job at keeping the finer particulate from getting through, but then it starts getting restrictive and you are not seeing the advantages of the freer flowing filter anymore. So you have to wash them quite often in dusty conditions.

 

Last point is that a free flowing filter such as a K&N, does its most good at higher rpms. They were designed for racing motorcycles the run in the several thousand rpm range. Longevity of the engine was not a factor, because those engine were rebuilt after a couple of races anyways. Those dirt tracks were wet down, so not a lot of dust. I personally don't see any advantage using a K&N on a Comanche engine.

 

Cold air intake yes, and so to get it, you pretty much are going to have to use an aftermarket filter.  Another catch 22...

[Keyav8r]

Thanks for all the input. Since old B,S&T will be a 2WD street truck, I'm not greatly concerned about micro-filtration, more about making a little room and a cleaner look. Cold air intake would be nice, but I'd like to keep the cost reasonable so a cowl intake is out.

So, I'm thinking a Spectre filter and Rusty's air tube like onlyinajeep has or maybe modify the stock airbox to move it forward and open up the inlet so it could draw more cool air from behind the grill.

But, if I can hit a JY find like Wrz, that would work too!

[Lee21490]

 

 

http://shop.trailheadoffroad.ihostnetworks.com/productinfo.aspx?productid=XJCI91-01

 

Rob

 

 

That is freaking awesome.

 

And pretty cheap compared to most cold air intakes too..

 

I think i will totally snag one of them, after i finish lifting my 'manche :3

[GirsMJ86]

:agree:  Though I'm not going to wait. I'm going to be ordering one soon and store it for when I have another 4.0L rig.

 

It also has me thinking about if there is enough room to rig something up for the 2.8L in a similar fashion, I kind of doubt it since the edelbrock open sided round filter gets crushed by the hood already.

[Lee21490]

:agree:  Though I'm not going to wait. I'm going to be ordering one soon and store it for when I have another 4.0L rig.

 

It also has me thinking about if there is enough room to rig something up for the 2.8L in a similar fashion, I kind of doubt it since the edelbrock open sided round filter gets crushed by the hood already.

Refer to my user pic. lol

[GirsMJ86]

Refer to my user pic. lol

 

I thought about that, or the cowl hoods, but I'm someone who just can't bring myself from straying too far from stock look. Plus, with it being the 2.8L I don't feel like spending too much to "improve" it. Previous owner stuck a Holley 2D injection system on it and some Edelbrock stuff, I never would have done that, though it is nice.

[Lee21490]

 

Refer to my user pic. lol

 

I thought about that, or the cowl hoods, but I'm someone who just can't bring myself from straying too far from stock look. Plus, with it being the 2.8L I don't feel like spending too much to "improve" it. Previous owner stuck a Holley 2D injection system on it and some Edelbrock stuff, I never would have done that, though it is nice.

 

I was basically broke when i did that. Old stock carb just up and died one day, Had a holley 4 barrel laying around, After adapter plates / etc it wouldnt fit under the hood anymore  :rotf:

 

If you look closely you can see the filter sticking through the hood

[jimoshel]

For normal everyday driving, you're not going to beat the stock air filtration system. Why spend bucks on something you don't really need?

[Bmoore2]

 

 

 

http://shop.trailheadoffroad.ihostnetworks.com/productinfo.aspx?productid=XJCI91-01

 

Rob

 

 

That is freaking awesome.

 

And pretty cheap compared to most cold air intakes too..

 

I think i will totally snag one of them, after i finish lifting my 'manche :3

Will these fit the 4.0 that came in the 88 comanche or do they have to be the 4.0 HO?

[Blue88Comanche]

 

 

 

 

http://shop.trailheadoffroad.ihostnetworks.com/productinfo.aspx?productid=XJCI91-01

 

Rob

 

 

That is freaking awesome.

 

And pretty cheap compared to most cold air intakes too..

 

I think i will totally snag one of them, after i finish lifting my 'manche :3

Will these fit the 4.0 that came in the 88 comanche or do they have to be the 4.0 HO?

it looks like you will need the throttle body adapter posted earlier on this thread to make it work

[Wrz]

 

 

http://shop.trailheadoffroad.ihostnetworks.com/productinfo.aspx?productid=XJCI91-01

 

Rob

Do you hear the intake inside the cab? I was going to go that route on my dd xj but a few ppl said it gets pretty noisy in there

Thanks

[RockMJ]

If you wanted to throw a half CAI into the Jeep, Rusty's makes an "Intake Tube" which utilizes the factory intake hose, removing the box, and putting a K&N cone filter in its place. This is about the only product I would mention from Rusty's and it is fairly inexpensive as well. Link below.

 

http://www.rustysoffroad.com/jeep-performance-parts-products/jeep-intake-systems/rustys-airtube-xj-cherokee-1.html

 

Unfortunately, as you have found out, not too many manufacturers make much in the way of aftermarket for the Renix equipped Jeep's. Hope this helps,

 

RockMJ

[GirsMJ86]

That's what was on my 91, along with a k&n cone. Worked fairly well and looked decent. Always wanted to rig up a heat shield around it though to shield it from the engine.

[Lee21490]

While we're on the subject of intakes, How much difference does a 63mm~ bored throttle body make for power?

[Alexia]

While we're on the subject of intakes, How much difference does a 63mm~ bored throttle body make for power?

Bored throttle bodies only make the throttle response sharper and assisting the higher 4,000+ RPM range on stock HO engines. On Renix engines with the tiny throttle body and poor flowing 2686 cylinder head it may see an overall improvement. Stock engines are decently matched for their intended RPM range in total flow from intake to exhaust with exhaust usually being the most restrictive part after the throttle body and cylinder head were upgraded for HO engines.

 

The stock air intake system's restriction is mainly at the inlet to the air box and the fact that it tends to get hotter air from the engine compartment. The stock filter size is big enough. Air intakes that actually relocate the air source to a cooler location such as the cowl with a sufficiently large enough filter are an improvement. Those that just leave the filter in the engine bay with a dinky little heat shield are worthless.

[RockMJ]

 

While we're on the subject of intakes, How much difference does a 63mm~ bored throttle body make for power?

Bored throttle bodies only make the throttle response sharper and assisting the higher 4,000+ RPM range on stock HO engines. On Renix engines with the tiny throttle body and poor flowing 2686 cylinder head it may see an overall improvement. Stock engines are decently matched for their intended RPM range in total flow from intake to exhaust with exhaust usually being the most restrictive part after the throttle body and cylinder head were upgraded for HO engines.

 

The stock air intake system's restriction is mainly at the inlet to the air box and the fact that it tends to get hotter air from the engine compartment. The stock filter size is big enough. Air intakes that actually relocate the air source to a cooler location such as the cowl with a sufficiently large enough filter are an improvement. Those that just leave the filter in the engine bay with a dinky little heat shield are worthless.

 

Truer words were never spoken! I could not agree more Alexia. If you have ever popped your hood after running the Jeep for a long while you will no doubt feel how incredibly hot the engine bay is. A true CAI relocated the point of induction someplace out of the engine bay to keep the intake temperatures down. Most cars and even some SUV/Trucks have kits to relocate the filter down to the inner wheel well behind the front bumper for this exact reason. There are obvious risks with doing so on a Jeep or a vehicle that seems extreme weather but to each their own. You will notice an improved throttle response and little to no improvements in mpg's or HP/TQ gains. For what it is worth I still run them knowing what it is they do and don't do. Like Alexia said, if you want to make it a true "cold-air" induction system you should focus on relocating the inlet pipe someplace out of the engine bay. Good luck!

 

RockMJ