Exahust and Intake Modifications

[Explorerdude]

Hey everyone,
This site is great. I'm very happy i finally found some place to get info on modifing my explorer. Well first off, I own a 94 Explorer XLT with the 4.0 Liter in it. Next I'm planning on doing several mods to the exahust and intake system.

First and easiest, I'm replacing my factory exhust with a Flowmaster Cat back system. That job should be easy to do. I was wondering if anyone knew whether or not it make a whole lot of difference in performance if I went ahead and replaced my cat with a high flow cat while i was replacing my exahust. What would be the benifits of doing that? Also, would it make since to also go ahead and install headers at that time? Where could I get headers?? How difficult is it to install the headers on my 4.0 liter?

Next I was going to install a conical air filter. I was reading about people using a KKM filter. I have know idea what that means. I know what the K & N filter charger is and am quite familair with it. I checked today with K & N to see if they made one for my model year but they don't. They only make filter chargers for 95 and newer. Could I use a charger for that year?? Has anyone on here done that?? Could I make slight modifications to the system to get that to work?? If so has anyone done that? Lastly I was reading several other peoples responses and read something about the MAF. I know a pretty good deal about older engines but I'm not too familair with these new ones. Although I'm guessing that a MAF is the unit that sits in front of the box my air filter sits in. What would be the benifits of having a bigger MAF? The next question is, where could I get a bigger MAF and how much does it cost?

Lastly I'd like to send out an invintation to all you fourwheelers in the Maryland DC area who own a lifted or slightly modified explorer. If you're into the fourwheeling thing and would like to do some legal great non competitive just all out having fun fourwheeling contact me. I have access to about 75 acres of quarrie running. It's great. Contact me and we'll set something up.

Thanks for your advice!!

Drive it like ya stole it!!,

Joe

 

[bachelor25]

Hey Joe, glad to have another Explorer owner on board, especially one who is into modifying it! Here is my experience/opinions on your questions.

The cat-back exhast change is a relatively simple procedure, and you'll find it actually takes longer to get the stock system out than it does to put the new baby in. I've got a Borla cat-back and have been very happy with it. Changing the cats to high flow is usally only recommended if your existing cats are dead. The price of the new ones is quite high, and the power gained is relatively small. The headers are another matter though. They offer a great performance increase, but are supposed to be a lot of work to install.

The conical filter is a great idea, but you're right, your '94 uses a flat filter, and the K&N replacement will be the same as stock. I've got a '96 Explorer so mine came with the conical one from the factory, and I changed it to a K&N. What you can do though is buy the KKM True-Rev Sport Induction Kit. KKM is actually the short name for Kurtz Kustom Motorsports, and you can find them and their products at Many people here have installed their product, and are very happy with it. I will be actually replacing my K&N with a KKM setup at the same time I switch to a larger MAF. Now for your MAF questions. You're correct the MAF is the sensor after the air filter that reads how much air passes through, and sends the info to the computer for air/fuel mixture adjustments. Having a larger MAF will allow more air to enter the engine, which will give you more power. With the better air filter setup, and your more efficent exhaust you will gain a noticeable increase in throttle response and power by adding a larger MAF. Check out the resources section on this web site for some links. Ford Explorer Ranger Mountaineer Navajo Bronco II Internet Resources Vanir technologies specializes in performance products for the Ford 4.0L engine, and makes a great selection of larger MAF, and throttle bodies.

Have fun modifying your Explorer, but remember you'll never be content! <grin>


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Cheers,

Andrew B.
1996 Ford Explorer 4x4 (slightly modified)
BC, Canada

 

[HPExplorer2]

Just a couple things - This is my first post to the message board, but it will definately not be my last. I have the borla cat-back system already installed and i would recommend that over anything else based only on the build quality and warranty of the borla system. I am not familiar with the flowmaster system so i cannot compare performance.

Borla Headers - the best price i have found is at (Dead Link) but being a loyal performance products customer, i asked them to match their price and they did it with a smile. My father also has the borla cat-back/headers on his explorer and the headers were definately quite the chore but worth every bead of sweat. Mine will be going on next weekend, wish me luck!

Hope this info helped out!

Tony


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Fast 91EB

 

[Phantom]

What diameter pipe is Borla using for their cat-back systems?

 

[Explorerdude]

Hey all,
Thanks for your quick responses. Dead Link Removed I ordered an intake from KKM. They look really good. What should I expect to get out of just the intake? My dad's not letting me do the exahust mod until the hole that's in it now gets larger and the muffler falls off. But I may order that too and just put it on without him knowing. I haven't decided yet. What kind of MAF would you recommend to use on the 94 4 liter?? How hard is it to do that mod?? What size MAF would you recommend?? What size throttle body would you recommend?? What make throttle body?? How hard are heads to put on?? Would you have to make other mods so the engine could handle that? Well thank you all for your input. When is that fourwheeling event down in NC?? Are there any other ones on the east coast?? Where is the one in NC located?? I'll keep you posted on how my mods go. Happy trails!

 

[Trane]

I have the kkm intake on my navajo, you'll defintely notice a difference as soon as you start it, throttle response is much faster and your engine revs up much smoother, excellent mod for the price.I also have the Borla cat-back, it's a QUALITY muffler with a good sound, Expensive but hopefully it'll be the last muffler I put on it. i live near Ocean City, MD, Once I get some different gears(another pricey mod) I'd like to check your quarry out.

Later
DANO

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93 navajo fairly modified

 

[Jordan714]

I asked for some help on this once before but never really got a clear answer. Maybe you all can help me a little more with this now.

I had my KKM installed for about 2 months before I took it off to go to the dealer for a check-up service. I didnt want them to see that I have modified anything at this point. Since I first put it on and when I put it back on I have gotten a VERY LOUD whistling,humming noise coming from somewhere in the intake at about 1700 RPM. I called KKM and they didnt have any idea what it could be unless I punched a hole in the filter, which ofcourse I didnt. Does anyone have any idea what could be causing this? I checked for air leaks everywhere and still cant find it. With my stock air system in place I still here the noise at 1700 RPM but its really quiet compaired?????? HELP!!

Thanks,

Jordan
98 XLT

 

[Trane]

Jordan714, Did you plug the vaccuum line?


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93 navajo fairly modified

 

[Jordan714]

Trane,

I am stupid on engine stuff so could you tell me a little more about this Vacuum Line? I didnt remove anything off except the stock filter unit and simply put on the KKM one attached to the black air hose going into the engine. Was there something else that I should of checked? If so, they didnt tell me in the instructions.

Jordan
(Still learning about Ford's)

 

[Trane]

I'm not sure what airbox set-up is like in a 98, but in my 93 I had two vaccuum tubes that hooked up to the airbox, I'm not sure what one does, but the other makes a hissing sound when the engine is started and causes the engine to idle roughly. My KKM kit came with an auminum plug for this. Again I'm not sure what the 98 set up is like, I may be talking apples while your dealing with oranges.

DANO

 

[dave dale]

Jordan
i have fitted a kkm air intake to my 1997 xlt sohc and there is no vacuum line

 

[Gern Blansten]

I have a 93', K&N does not make a kit for this year but KKM does. The only other post
I've seen from California-somewhere in Monterey I believe-said they couldn't get smog certificate without putting the box back on. Has anyone else in CA put on the KKM kit and had problems getting smoged?

Also, from 94-96' or something they did come with a conical air filter setup. What was different about these years, and who made the setup for Ford?

 

[Tyson]

I live in California and I have the KKM setup. When I spoke with them, they said don't even try to smog with the kit on. It won't pass visual. All you have to do is keep your stock airbox and swap it in every two years....

 

[Diff Whack Daddy]

Here is the scoop on the KKM and California smog. There is a heat riser that comes off the passenger side exhaust manifold and tees into the intake tube of the stock airbox. This is the reason why it doesn't pass the CA visual smog inspection. According the the smog tech, he say it helps atomize the fuel in the combustion chamber causing lower emissions. I had the smog guy run the test any way and then went home and swapped out to the stock air box and had the test run again and wouldn't you know it, KKM scored better than stock.

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93XLT-5.5" Super Runner, Super Runner Steering, 1.5" Body lift,33x12.5,
Plenty of Scabs on Hands