KDOG

Hello everyone, great to be here!

I have a 2004 Jeep Grand Cherokee Laredo 4.0L I6 with the 4spd Auto and SelecTrac TC. Supposedly its a pretty good setup. Today at the shop where I was getting my oil changed and diff/TC fluids checked etc., I asked him if there are any legit mods that could be done to increase power/efficiency. He stated that if it was him he'd put a Flowmaster exhaust on it with a Summit "airbox". He said it would give me a boost in both HP and milage.

I've heard of the Flowmaster stuff but not this "airbox". Can anyone explain it to me and give me some suggestions on what setup to get? Is it easy enough to do myself?

Thanks everyone!


EDIT: I guess a more general question would be what legit mods are available to increase power/efficiency?

1sckrs

Airbox is a part of the intake setup where the filter sits .. if you are not going to do serious offroading and not worrying about things being water proof I would look up cold air intake systems or even make one urself.

jeepxj07

You can go to advance auto and they have all the components for you to build your own cold air intake for around $80. I would just invest in a mud guard for your air filter because it is pretty exposed and you never know if it is going to muddy somewhere or not.

Texas XJeeper

Welcome to the forum from Texas

PolarXJ

A high flow air filter will help. IDK on the ZJ's but the k&n filter that replaces the stock filter on XJ is a bit two small and lets debris by. Its why I'm going to get a cone and got rid of the air box.

Welcome from UT, BTW.

KDOG

I've also heard the K&N air filters are actually TERRIBLE for your engine. I even saw somewhere (wish I could remember where) someone had a graph that showed where it lets something like 45x more dirt through. I used to have one in the stock box but decided to take it out after hearing that. Didn't want to risk my engine.

jeepkid46

They do thats the only way to make it flow more is to open the holes up

KDOG

I can't figure out why a more common sense solution to airflow hasn't been explored - could one just put a bigger airbox that uses a larger regular filter on and have still have the improved airflow without risking more contamination?

jeepkid46

Make one

dave1123

Actually, studies have been done that show the stock pad air filter will flow more than twice what the engine demands, but the intake piping needs to be larger. The only sugnificant improvement would be ram air or supercharging. Believe it or not, I've seen the 4.0 supercharged with a heater blower fan and it actually made a performance difference! It was a squirrel-cage fan with a round pipe outlet. It was rigged to a toggle switch for on-demand use only. Makes people crazy when you burn rubber with an old rusted-out Wagoneer!

Any reduction in exhaust back-pressure will also help, however you are stuck with a converter and not much can be done with that. The matrix must remain clean, however, or it becomes a strangler. As far as mufflers go, how much noise can you deal with? Most performance mufflers will do, the more money you spend determines how long they last.

BTW I've been drag racing most of my life. Welcome to the forum! If you can't find you answer here, you didn't ask the right question or weren't listening!

1sckrs

Dave your 100% right couldn't of said it better

GI-Jeepin'

Dave

The heater blower sounds interesting. Although a home made contraption will look as pretty as a soup sandwich, it may give enough low speed grunt to get over a steep incline or something.

makingaZJ

yeah throw a cold air intake and a cat back on it!

google "cold air intake" and "cat back"

they are really easy and quick mods you can do yourself that will improve your jeeps performance and sound.

KDOG

The cat back sounds interesting. I'm also interested in finding out more about the seemingly simple principle of channeling more fresh air through the existing filter. I may also take the other posters' advice and look into "building one" to do what I'm looking for. Thanks for the advice all...

1sckrs

Go on summit racing or jegs to get a catback they have a few diff good choices nd if you have knowledge of tools and cars or trucks you will be able to do it in a weekend or a day