Just installed the BBK 63mm TB and K&N intake on my 93 4.0HO Cherokee. I already have a 2.5" header back exhaust system with magnaflow high flow cat and super 40 muffler along with having eliminated my fan clutch and have gone with electric fans and no ac compressor any longer. I must say that I can no question "feel" a diffrence in power espically at low rpm's and the Jeep seems to just kinda go on it's own, and yes I adjusted the idle control screw on the TB. It seems to cruise at 55 at about 200 less RMP than previous and with less effort than before. Throttle response imporvemnt is not even a question as its much better not that it was bad before as the fan clutch elimanation cured that. I will post MPG #'s soon. Total improvement in power through out the RPM'S from 1000-4000 as far as im concerned, just wish I had a dyno to prove it. The BBK TB came with everything you needed and its a quality product. The K&N was so-so. I cut out alittle behind my grille and made the stock air box holes that see daylight towards the ground bigger to actually get more "cold air" and hopefully improve what its sucking in, and yes its sucks alot if you put your hand on the filter you can actually feel it. I had good results with this and I contribute it to the fact that I have alot of things working toghter not just one thing doing it all. Plese keep that in mind and realize this is not a Holy S it WOW why dont everyone do this mod. Hope (mabey) someone that was gonna spend alot of money looking for this info reads this.

 

After getting gas 3 times and putting on around 470 miles, as I fill up when I get below half a tank often I have been averaging 17-19 MPG each time. I typically drive this Jeep 34 miles round trip on mostly flat roads at 50-60 mph for 90% of the time. Doing these mods I feel that I use less pedal to get going and it "cruises" with less effort. I also warm this Jeep up for few minutes before I drive it because it has been rather cold here and I feel 20-22 mpg will become normal once warmer weather is here and idle time diminishes.

 

Thx for sharing this John. I also have a bored TB and CAI but only the factory header from my 1994 and I also can tell the difference...Tj