I was thinking of adding a air intake system to my 95 4.0. You see all kinds of claims for horsepower boost. Are these systems better than the stock set up? Anyone had problems with this setup? What about throttle body spacers? What do they do? If I change to the aftermarket air intake, should I install a throttle body spacer also?

I was thinking of adding a air intake system to my 95 4.0. You see all kinds of claims for horsepower boost. Are these systems better than the stock set up? Anyone had problems with this setup? What about throttle body spacers? What do they do? If I change to the aftermarket air intake, should I install a throttle body spacer also?


Hey Jeepme,


Yes, the CAI will give you a little more HP not much but it makes a nice whooshing sound! LOL I got one from Rusty's 4x4 and also changed the cat to a high flow and flowmaster muffler.

The TB Spacer is bogus it's just like that other one you see advertised called Tornado etc.

btw - Does your Jeep have the Closed or Open Rad System? I just changed mine and hopefully it will keep it cooler during Emissions Testing so I can have lower NOX and Pass!

Thx, Phil

Theres a difference between a cold air system and an open element air intake. A cold air system isolates an area under the hood and draws cooler, denser outside air in. A simple open element system draws hot air from under the hood. I think the advantages of a simple open element are minimal if any. Probably the only advantage is a less restrictive air intake. I think the cold air intakes do help some.
Ive heard both good and bad about the spacers. As far as I can tell its about a 50/50 split on whether or not they help. Some have claimed that they whistle badly. Theyre supposed to increase throttle response and the ones with rifleing machined into them are supposed to mix the fuel/air better. Thats a bogus claim on a MPI engine as there is no air/fuel to mix until well past the spacer. Same goes for the Tornado.
Bare in mind, I dont have personal experience with an open element or cold air intake or spacer because I personally dont buy into them. Its alot of money for maybe 5 or 10 HP, and what for, so I can get home from work 1 second faster. Ive got better things to do with $300-$400.
EDIT; It looks like you could pickup a open air intake and spacer for about $250-$300, Not as bad as I thought but still alot.

I guess the aftermarket air intake does fall under the "if it sounds too good to be true it is too good to be true" category. It seems like everywhere you look people are putting them on all kinds of vehicles. Must be the cool wooshing sound. There's nothing wrong with the performance of the 4.0 six anyway. With the 5 speed stick it's one of the quickest sixes I've ever driven. I'm sure I can find a better use for the cash.

Phil- Check out the emissions post for more on the NOX.