xj intake ideas. ram air/ supercharged... kinda

gboroxj

Active Member
Joined
Jan 24, 2010
Location
Greensboro
ok so 97 xj 4.0. ditched the stock air box a while back for a cold air intake. just a cone filter still on the stock intake hose. noticed a huge difference in power from the jeep. read an article online about a supercharged xj. looked at the price and decided that was not gonna happen. so me being a college student and having too much time on my hands and too little money i though about somehow having an eletric fan to force air in. sure enough go online and find this. http://cgi.ebay.com/ebaymotors/Elec...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
i found many other ones that were alot more pricey and had psi ratingings of 3 and 5. im broke... so will this cheap thing be worth my time?? also i know that cold air makes the engine run alot better. so then i thought that i could possibly have two options there. one is to get air some how from outside of the engine bay where the air is not heated form the motor, possibly a ram air or snorkel or something, dont want to go into fender or down because.. its a jeep it likes mud. option two... yet again way to much time on my hands.... i dont use my a/c and dont have a compressor right now but i was thinking that is it set all my air back up and somehow piped it all straight to the intake it would always have cold air as long as the compressor ran and the fan. this would take some work but i could figure something out. but running the compressor drains Horse power from the engine and i doubt it would be a good enough trade off to be worth it. im not trying to put this thing on nitrous or anything just make it run better and have more power. what do yall think? am i wasting my time? 1 is the cheap supercharger worth a poo, 2 would either of the two cold air options be worth my time and effort?
 
Okay, where to start on this one....
The $29 "supercharger", if you could get decent gains from a $29 heater blower motor with a tube on it, nobody would pay upwards of $2000 for real superchargers. Think about it.
Going to true "cold air" isn't going to make a big difference, and really isn't worth it if you plan on going anywhere wet. Trying to get the engine to suck through a snorkle isn't going to increase power, just move the intake above the water line. Colder air doesn't always mean more power, if you're getting enough in to match the fuel the EFI squirts in the cylinders it works. If you want to be able to get a little more fuel in you can drop in a 160* thermostat, making the engine run cooler will cause the computer to richen the mixture, but normally just enough to get you a little less mpg unless you've made other mods.
If you truly want more power, save up a little money and start making mods, but tossing $30 here and there on b.s. just keeps you from putting that money back to make mods that will get you a performance gain. There are a ton of members on here running 4.0's that have done everything under the sun to them, surely they can point you to a good starting place. The aftermarket for them is pretty supportive.
 
x2. i have a 92 xj. i change my oil. thats it.
trust me when i say this> if you have a xj save your money now bc you will need it.
 
yeah i have been making mod that were worth my money so far. lift bumper winch tires wheels exaust ect... just wanting more power now though. all started with a thought to re-gear but even that is costly but not near as bad as a super charger. thanks for the advice. just not wanting to spend a whole lot just wanting some more get up and go. and as for the water issue. i dont do a whole lot of four wheeling but when i do i would like to keep the ability to go through two or more feet of water with out thinking twice. so an option on that mihgt be a home made ram air that sticks up like a hood scoop, but how do you keep rain out of them? and jweezyferg, i know i have had it for two years, it has 214000 miles and used pleanty of $$ on it. i like to call it my parts jeep, it goes through them on a weekly basis
 
32s 3.55s and yeah i have been looking into it. only issue is its pricey and i want the best of both worlds.. fuel economy and torque
 
RenegadeT said:
what gear and tire size are you running? Re-gearing just might feed the 'power' jones you're looking for
Click to expand...

If you keep your eyes open in the classifieds section or on Craigslist there is occasionally someone parting out an XJ or like rig that can save you some time and money regearing it. A D30 out of an XJ or TJ should fit the bill, and a rear from an XJ, ranger or explorer will work without much issue.
 
dude, you need to stay off of fleabay. If it actually worked, 1) why would people spend 10 times as much to do the same thing. 2) you would need some ability to reprogram the fuel and timing. No matter what it says, when introducing pressure above atmospheric pressure inside the intake the computer cannot compensate, fuel pressure must be increased by the amount of boost present to prevent a lean condition. 3) Says it is safe to use to pressurize a standard carburator, if you put actual pressure down the throat of an unmodified carb it blows out past the throttle shafts (reason people spend lots of time and money to make blow through carbs) 4) not designed to run continuously according to the ad I'm stopping now, but you see where this is going.
 
gboroxj said:
32s 3.55s and yeah i have been looking into it. only issue is its pricey and i want the best of both worlds.. fuel economy and torque
Click to expand...

Find a set of 4.10 axles, it will do what you want, and its not to overboard. You can find axles for an XJ geared 4.10 you just have to look for them.

The ebay stuff is set up so that "young" people that don't know any better will spend money on it. I commend you on asking opinions first. I was just like you years ago and tried all the gimmicks and that just what they are, if they were that much of a help they would cost allot more. Aside from stroking the 4.0 there are just small little things that will improve it as in running better, but nothing that is going to be worlds of a difference in HP.
 
yeah. thanks alot on the help guys would i loose all my gas mileage and highway driveabilty if i found some 4.10 axles? it has 32s on it and i dont plan on upping the tire size anytime soon.
 
gboroxj said:
yeah. thanks alot on the help guys would i loose all my gas mileage and highway driveabilty if i found some 4.10 axles? it has 32s on it and i dont plan on upping the tire size anytime soon.
Click to expand...

no, it would probably be exactly what you're looking for, maybe a little "pricey", but any mods worth a crap are gonna cost ya.
http://www.4lo.com/calc/geartable.htm
Right now with 32's and assuming ratio of 3.55, you are at 2432 RPMs @65MPH. With the factory 29" P235s, it was 2674. Bumping to 4.10, your 65MPH cruise RPM's will be 2805.
But with an overdrive automatic in your XJ, this is kind of bogus information. You will definitley notice better acceleration, maybe that will slightly chip into fuel economy. Cruising the highway, the only thing you'll notice is on long steep grades, it will no longer need to downshift. I have a 99XJ on 31s, factory 3.55, and it will drop out of OD every so often on the highway.
 
i like this chart. so your saying if i had 4.10s with my 32s it would have a very slight change in gas mileage, i get about 15 mpg now with 3.55s... any estimation? like 13, 14, 12? and it would have alot more torque and have less trouble on the highway... such as going up to boone on 421 would it not have to slow down as much and if it was a little quicker around town. if it stayed in that range for gas mileage and got that much more power it would be worth it, how much would i spend to find a dana 30 and a chry 8.25 with 410s? could i go to a dana 35 or is it weaker?
 
gboroxj said:
i like this chart. so your saying if i had 4.10s with my 32s it would have a very slight change in gas mileage, i get about 15 mpg now with 3.55s... any estimation? like 13, 14, 12?
Click to expand...

Estimating the fuel mileage is really hard, But I would say it wouldn't be that noticeable, You will gain some mileage in some types of driving and lose a little on others. But IMO it will offset and be a slight change. Now if you went 4.56 or 4.88 it would be worth the worry.

gboroxj said:
it would have alot more torque and have less trouble on the highway... such as going up to boone on 421 would it not have to slow down as much and if it was a little quicker around town
Click to expand...

Yes it will have a very noticeable difference in Torque, You would really notice it on 421 and it will be quick on the bottom end, top end will decrease slightly.

gboroxj said:
if it stayed in that range for gas mileage and got that much more power it would be worth it, how much would i spend to find a dana 30 and a chry 8.25 with 410s? could i go to a dana 35 or is it weaker?
Click to expand...

I would stay clear of the D35, the D30 and 8.25 are plenty good up to a 35 inch tire. There not axles that are being swapped in commonly, but they are being swapped out to run larger tires, so if you keep your eyes open you can run across them. As far as price it varys a ton, so its hard to say.
 
Back
Top