[256ChiliPepper]

I have done a 4.0L throttle body swap which improved a little more top end, it was free from a friend. Taurus electric fan ($20 fan from junk yard, and $30 controller from Autozone) Flomaster muffler (not sure on which one, but got it free too) I did these all individually with running a tank of gas through between each one.
This was all after i had already regeared to 4.88s with 33s, but i did notice a little more power closer to the top end. Granted i doubt I'm getting any really benefits from them, except a seat of the pants feel, and the motor winds up easier. The 4cyls like to rev some so don't be afraid to push it a little more. Best power for your money would be gears.

[Wrangler413]

Originally Posted by Unlimited04

this is the correct answer.

thanks for actually listening to my post, v8 cost so much money, and im thinking of just re gearing it to 4.56s or 4.88s with a rear 44. Maybe a oversized throttle body spacer, then just a K&E drop in air filter. And with recent post, ive actually done better on trails then my friends 4.0 but his is a manual and mines an automatic, maybe thats the difference but im not sure. All and all im fine with my 4 cyl because i bet i can do most of the things that a 4.0 can other than pulling people out lol. but thanks everyone for your info on the 4 cyl, but for the idiots who think i should put a v8 in my small a$$ 97 can suck it lol, ill keep my mpg

thanks everyone(besides v8 idiots who didnt help at all cause it would be more than a supercharger..

[armyman89]

dont use a throttle body spacer they are junk they dont do much if anything you will lose power i would stay away from K&N i have never had good luck with them they let in to much dirt try to find an afe dry filter better than a K&N. next i would upgrade my alternator like one from a durango and then i would install my efan from a trauas with a thermostat and a on/off switch next i would pull the manifold off and gasket match the ports for a smoother air flow next i would add the 4.0 throttle body. next i painted my exhaust with header paint to keep the heat in the pipes and i could tell a small difference nothing major but i could tell the inside of the jeep got cooler and the engine runs cooler now that my exhast is getting more hot iar out then having it radiate around the engine compartment

[tommzz]

Just throwing this out there, maybe the 2 more cylinders theme isn't such a bad idea afterall. I mean if you're going to go through the trouble and expense of doing a regear, wouldn't you be better off just selling the 4 cylinder and buying a 6 cylinder. This would allow for much more flexibility in the future. Its a personal preference but I know when I was looking around for a Jeep everyone I spoke with warned against the 2.5L. No offense....just saying.

[Pallando]

Originally Posted by tommzz

Just throwing this out there, maybe the 2 more cylinders theme isn't such a bad idea afterall. I mean if you're going to go through the trouble and expense of doing a regear, wouldn't you be better off just selling the 4 cylinder and buying a 6 cylinder. This would allow for much more flexibility in the future. Its a personal preference but I know when I was looking around for a Jeep everyone I spoke with warned against the 2.5L. No offense....just saying.

2.5l Jeeps are perfect candidates for engine swaps, though! I'm eventually putting a VW turbodiesel in mine.

[99_TJ_Wyoming]

Originally Posted by RubiconRazorbac

It's even funnier how much BS was in your post. Especially when your last statement states the 4 cyl has "advantages" over the 4.0 or a V8.

There's nothing wrong with a 4 cylinder, but to claim it's somehow superior to a 4.0 L or a V-8 is the dumbest **** I've ever heard. I've had all 3 and I promise, my '97 with the 2.5 didn't have a single advantage over my old CJ-5 (V-8), or current '03 (4.0 L).

I'll steal a quote from another JF member: "You can never have too much horsepower, steering, or brakes."OP, don't waste your money on a bunch of crap that will only change the way your Jeep sounds. You won't get any useful gains in performance other than from a lighter wallet. If you need more performance, save up for a re-gear.

Saying "You can never have too much horsepower" is like saying "I have no skill and have to rely on 'when in doubt, throttle out'", that brings me to my favorite saying for people like you - ""Didnt I see you being stupid then upside down on youtube??""

[wushaw]

Originally Posted by Wrangler413

thanks for actually listening to my post, v8 cost so much money, and im thinking of just re gearing it to 4.56s or 4.88s with a rear 44. Maybe a oversized throttle body spacer, then just a K&E drop in air filter. And with recent post, ive actually done better on trails then my friends 4.0 but his is a manual and mines an automatic, maybe thats the difference but im not sure. All and all im fine with my 4 cyl because i bet i can do most of the things that a 4.0 can other than pulling people out lol. but thanks everyone for your info on the 4 cyl, but for the idiots who think i should put a v8 in my small a$$ 97 can suck it lol, ill keep my mpg

thanks everyone(besides v8 idiots who didnt help at all cause it would be more than a supercharger..

You must not understand power to weight ratio thing. You put something like a 300hp v8 in your jeep and it will get better fuel economy than your 4 cyl is currently only if you don't drive it like you stole it.

I don't have a v8 in my jeep nor do I want one, I was just pointing something out about them.
Your 4cyl is just fine for off road, hwy driving is what it is.

[csm41]

Originally Posted by sshankle

I have the same motor. I have put a throttle body spacer, cold air intake and felt very little gain. I changed out the stock exhaust header for a pace setter header from Jegs ($180) and noticed immediate gains. Not much more over the cold air and throttle body spacer but there was definitely a difference. I also changed out the ignition for an accel and plat plugs. I run 265/75/16 all terrain and can run 77 on the interstate according to gps.

This is next on my list of things to do ...

A friend of mine changed out his fan for an electric fan off a honda civic. Did some minor trim work on the shroud, ran it off a toggle switch and it did great. Said it was instant horsepower that he could feel. His only regret is that it didn't have a thermostat for auto on/off. His wife almost torched it when she forgot to turn the fan on. So, you may want to pony up and pay the extra bucks to get the right set up.

He, also, changed out his 2.5 throttle body for a 4.0 throttle body for slight increase that he could feel. I believe the sensors bolted on the 2.5 throttle body will bolt on the 4.0 throttle body so don't discard those or buy new ones.

That about all you can do as far as engine bolt ons. If you did all of this one at time, you would think you wasted your money because the gains are slight and barely noticeable. You will notice it more if all of this was done at one time. Keep in mind that this is a 4 banger with bolt ons and you can only squeeze so much out of it without getting deeper into your pocket book.

Anyway, hope this helps.

I had a 99 4 banger about 10 years ago and did all of the above. While there was an improvement, in the end it wasn't worth the time and money. That 4 cylinder is a good little motor, and if cared for, can go 300k or more miles. Keep the motor stock and save some coin. Get a regear because that is where you will feel a real difference. I did Super 35 and Super 30 with OX Lockers and 4:88 gearing along with some other mods (35's, armor etc.) and that Jeep went anywhere the other Jeeps went. Oh, one other thing. Do your best to keep the weight of the Jeep as light as possible.

[Unlimited04]

Originally Posted by Wrangler413

thanks for actually listening to my post, v8 cost so much money, and im thinking of just re gearing it to 4.56s or 4.88s with a rear 44.

just to be clear, regearing doesn't give you more power. it moves the existing powerband vs driveshaft rotational speed.

Originally Posted by Wrangler413

Maybe a oversized throttle body spacer, then just a K&E drop in air filter.

why would you buy that worthless crap?

Originally Posted by Wrangler413

And with recent post, ive actually done better on trails then my friends 4.0 but his is a manual and mines an automatic, maybe thats the difference but im not sure.

yup, manuals can be a PITA if you don't know how to drive them well off-road. they stall out.

Originally Posted by Wrangler413

All and all im fine with my 4 cyl because i bet i can do most of the things that a 4.0 can other than pulling people out lol. but thanks everyone for your info on the 4 cyl, but for the idiots who think i should put a v8 in my small a$$ 97 can suck it lol, ill keep my mpg

well most v8 swaps get better mileage than a 4-cyl or 6-cyl TJ. The mileage is better because the engine doesn't have to work near as hard to keep the Jeep moving, the torque curve is typically much stronger at lower RPMs, right where you want it. suck on that.

Originally Posted by Wrangler413

thanks everyone(besides v8 idiots who didnt help at all cause it would be more than a supercharger..

actually several members on this forum have done nice write ups on V8 swaps for under $2000. I think one was $1200 total. Might want to search before you say "suck it".

[Acrowe]

I think there are pros and cons to several sides here. More power is always nice, there is no doubt having more hp is nice. Swapping to v8 is almost certainly going to cost much more than 2000 unless you get the engine and hardware way below market value (some people are eBay/wheeler dealer geniuses and can trade a used tire eventually to a complete running jeep- most of us aren't including me). You also need to be able to do it with no technical assistance which for some swaps is pretty doable but a little daunting for many.
The 4.0 does not get better fuel mileage than the 2.4. My 2.4 with 32s is noticeably cheaper than my brothers 4.0 and my friends rubicon with 31s. Part of this might be because I drive slower, but it is also cheaper around town (and not too slow around town). The 4 cyl is much lighter and this does help off road in many situations( lighter and less hp means less broken stuff with stockish drivetrain). Chevy 350 is a heavy engine and with the weight and hp you will soon need stronger (expensive and heavier) axles.

Don't get me wrong I like hp and think v8 swaps are cool but I just put up with driving slower on the highway

[M_Hudek]

Originally Posted by Wrangler413

I have a 4 cyl and I was wondering what upgrades I could get to give me a little more power, just let me know what you think
P.S I don't have a ton on money to spend...so now superchargers or anything like that

just add 2 more cylinders..should get the job done

[andy02]

Originally Posted by Acrowe

Swapping to v8 is almost certainly going to cost much more than 2000 unless you get the engine and hardware way below market value (some people are eBay/wheeler dealer geniuses and can trade a used tire eventually to a complete running jeep- most of us aren't including me).

It is not the parts that cost the most money. It is the labor if you can't do it yourself. I rebuilt a 351C with 2v heads (eventually swapped to Dart II heads) when I was in highschool. Followed it by a reverse valve body 3 speed powerglide tranny, all dropped into a Mustang II for less than 2K.

[YouStupidBunny]

I've tried almost everything to improve my 2001 2.5L.

Here are a few things that I know did not help:

Cold air intake- While it did seem to help throttle response, that shouldn't be confused with more power. I think some believe throttle response translates to more power. I left it in because getting slightly cooler air can't hurt here in the desert.

Cat back exhaust- Again, better throttle response, but no power increase. It did help in the higher RPM's on the interstate, but I lost power in the lower RPM's. Sounded aggressive, but the noise gets old fast. I ended up making an even trade for my Banks exhaust for someone else's stock exhaust. After I went back to stock, my low end improved.

4.0L throttle body- Once again, better throttle response, but no change in power. I left it on for the same reason I left the CAI on.

Jet Power Chip- I thought for sure it worked well. After chasing an idle issue, I took it out as part of the diagnostic process. With the chip out, all the improvements I noticed with the chip in were still there. Complete placebo effect. It now sits on my spare parts shelf.

Mustang 4 nozzle injectors- Same as above. I thought it improved, but after going back to stock, there was no change. Another placebo upgrade. Also taking up space on my spare parts shelf.

Electric fan- This upgrade did help a little, but I felt the improvement was too slight. After my Efan died, I put the clutch fan back on. The improvement was too slight to hassle with another Efan again. The only thing I miss about it is its ability to cool better at idle which is awful here in the desert.

As you can see, I've tried almost everything that could bolt onto a 2.5L and almost everything is back to stock. Here are a few things that did work well enough to keep:

Screamin' Demon ignition coil pack- I've seen this system on 4.0L's with no noticable improvement, but I also know that what may not work on a 4.0 may improve my 2.5. After all, they are different motors. This actually did help. Idle is smoother. Getting up hills a littler easier and cruising highway speeds in improved. More importantly, my MPG is up almost 2 MPG. That made it worth the upgrade to me.

Regear- This was, by far, the greatest improvement for my Jeep. I was running a 3-speed auto, 31" ProComp's with stock 3.73 gears. I was getting passed by school buses. Imagine a bus load of punk 7th graders all giving you the finger. After regearing to 4.56, getting up to highway speeds was easier and safer.

I've spent a lot of money trying to perk up my 2.5L and only two of the upgrades were worth it. Despite that, I don't regret any of it. As long as it's not cleaning or a repair, I enjoy working on the Jeep. Hopefully, you will too.

[RubiconRazorbac]

Originally Posted by 99_TJ_Wyoming

Saying "You can never have too much horsepower" is like saying "I have no skill and have to rely on 'when in doubt, throttle out'", that brings me to my favorite saying for people like you - ""Didnt I see you being stupid then upside down on youtube??""

Say what you want dip****, you said the 4 cyl had advantages over the 4.0L and a V-8. Name one--because a 4cyl in a TJ doesn't get MPG worth a crap either.

[RubiconRazorbac]

BTW your assessment of my driving is inaccurate. I'll take finesse over force anyday.

But sometimes, you need the power. In the OP's case, to turn larger tires efficiently.

How many threads do you see asking for instruction on how to swap out a 6 cyl or V-8 so they can put in a 4 cyl (4BTs being the exception)? How many people start threads with "My Jeep has too much power, how do I de-tune?"