2.5L performance?

[quicksand97]

Well here is my point of view or my personnal opinion with my 2.5L power plant. O yeah at first when it was stock I did not like it at all on the highway, I had to lean foward to maintain 55 mph, that was before my lil 31s. Then I got 31s bfgs and it looked much better. Yeah setting in driveway. Then ofcourse the search began. In search of more power. Thru time and trail and error it was one mod after another. Some worked real good and some did not yeild any noticible gains. Then on top of it all it was done on a budget. Years later I am super happy with my 4 banger. It has a homemade cold air intake with modified factory air box, cut out on front side of box and on the side with a adjustable air plate. The air plate allows me to fine tune the amount of air coming in for my specific mods. I believe not one cold air intake system fits all. Every rig has different needs for air and spark. Cold air inters thru from the front of the rig from a removed headlight bezel. Air is keeped cool by heat wrapping the air intake tube. I did finally get a 4.0L throttle body with made a big difference of course that sits on top of a custom throttle body spacer with air velocity blades. The factory 4.0L TB starts at 60mm on top side and tapers down to 55mm on bottom. This also worked for me because it also helped to keep air intake under presure. The custom spacer is 60mm on top side and 55m on bottom side. Yes the factory intake manifold has a bore of 48mm if I remember correctly and I did bore the manifold to 55mm to macth spacer. Also in order to keep things fired up I installed a accel coil which is rated at 42,000 volts or maybe 48,000 volts. That was mated with 8mm accel coil along with NGK plugs gapped at .040. Magnaflow muffler and cat also help my lil rig scoot down the highway alot better and is a joy to drive along with moderate passing power. I can hold 80mph on a straight way and with a headwind and uphill she holds 70mph. O yeah I also did something real getto and I trimmed my factory air blades on the radiator fan. O yeah it was spooky I did it lil by lil in order to reduce drag. I had to be careful not to reach the point of no return. I did get it where she still cools engine down as before, even better she winds up a bit faster at take off. I did once try a 62mm throttle body but it did not work for me. I lost passing power on highway. But it might work for someone else. I am considering getting a electric fan but for now I am very happy with my performance all the way around. Happy enough to put a 2.5L sticker on somewhere. My next mod is some magnecor wires to make sure I am getting getting every bit of spark. Now mind you I am still running 31s with a budget boost, but I tell you what for a daily driver this thing kicks. Yeah if I throw on some 32s or 33s I am sure I would need to swap out the 4.10 gears. All in all I have no regrets and when it comes time to rebuild I would do it again. I believe in the power to wieght ratio. Note I do keep my wieght down to minimum. Thats my 2 cents worth. Happy Wheeling.

 

[O_M_Jeep]

The electric fan is the mod that has shown the best results for me, it isnt difficult, some people like multi-speed temp controlled, all kinds of expensive stuff, it isnt needed, I used a $80 fan from O'Rielly, a 30amp relay, and a switch inside to kill it, when the engine is running the fan is running, I used a covered switch so I wouldnt turn it off and forget its off. I live in wyoming and wheel Moab, so Ive used it in tempratures from -35 to 105 and the Jeep always stays at 210, never fluctuates, in extreme cold I leave it off, in extreme heat at low speed Im moving more air than the mechanical. I used a simple fan and left the stock shroud in place. I will say the only problem Ive ever had on the trail though was with a fan, it was a fan from Carquest and wasnt as beefy as the O'Rielly fan and at a year old it shorted and caught fire on the trail, no damage to anything but itself, but at 95 degrees, we had to get towed from the trail head back to camp. the new fan compared side by side is so much better made its amazing, very tough, very well built, and $80 or $100, not the $400 or $700 you find at Jeep sites. If you want an easy way to get more power, that is the best imo.

 

[Bounty__Hunter]

The Taurus fan is heavier and better made than any part-store fan I've seen, hard to beat OEM quality at a fraction of the cost.

Why keep the large OEM fan shroud with an electric fan? Losing it is one of the benefits of the conversion, allowing room to work, room to stand on the front axle while working on the engine.

 

[cali_92]

Why keep the large OEM fan shroud with an electric fan? Losing it is one of the benefits of the conversion, allowing room to work, room to stand on the front axle while working on the engine.

the reason why you leave it in is so when you open your hood you hope the person next to you doesnt notice that your engine compartment is 50% fan shroud.

 

[O_M_Jeep]

You leave the factory shroud to create a vortex within the tunnel to assure air flow through areas the fan doesn't cover when moving at low speed

 

[Bounty__Hunter]

I'm not buying it. The taurus fan has its own shroud and covers about 90% of the Wrangler radiator. No reason to leave the factory shroud, it's just in the way.

 

[O_M_Jeep]

But I'm not using the Taurus fan, so buying it isn't necessary till you try it

 

[Bounty__Hunter]

So you're saying there's a vortex at slow speeds?

 

[House Norris]

Hey guys I changed out my radiator, top hose, and thermostat. Plus all new fluids. My engine is a 98. 2.5 in a Wrangler with auto transmission. After triple checking all my connects and adding cooland and ATF my engine runs hot almost immediately when I start it. I have no visible leaks. Help.

 

[luis]

Hey guys I changed out my radiator, top hose, and thermostat. Plus all new fluids. My engine is a 98. 2.5 in a Wrangler with auto transmission. After triple checking all my connects and adding cooland and ATF my engine runs hot almost immediately when I start it. I have no visible leaks. Help.

Did u install the thermostat backwards? Did u get the correct thermostat cuz some open at different temps

 

[O_M_Jeep]

ok, air works on some of the same properties of hydrodynamics, if you have a narrow jet inside a water pipe, the water not directly in front of the jet will be propelled as well by the current, air also flows in currents.

I run a 16" fan, this leaves a few inches to either side not directly affected by the fan (without the shroud), if you were to use a piece of paper a few inches in size and hold it to the outside of the radiator over the fan, the fan would keep it in place, if you were to put it in a place the fan wasnt, it would fall, with the shroud, it is still held in place, the vortexual nature of air current through a pipe (in this case the shroud) ensures that there is air flow through all of the radiator when stationary.

 

[Bounty__Hunter]

Makes sense, but have you ran without the shroud and noted any differences?

 

[O_M_Jeep]

I haven't, taking out the shroud for me would mean relocating the coolant and PS reservoirs

 

[quicksand97]

So you do not run a termostat with your fan? Just a swicth right? I am interested in the way you have it set up. Correct me if I am wrong it is wired so that it comes on when engine comes on? and off when engine is off? with the option of a off and on swicth Is that correct? O is it possible to post some pics? I like the fact about using it along with the factory shroud as a funnel affect with full coverage of rad keeping air tight.

 

[O_M_Jeep]

Thats correct, always on with a kill switch inside, I used a switch with a flip up cover so I would notice if I forget to turn it back on, to do that you have to have the switch on the ground wire, not the positive wire to the relay, I'm at work now but I will post some pics when I get home in the am.

 

[jfrabat]

Nothing personal JFR I absolutely hate that answer "just buy a 4.0", I love my Jeep, it has history and love and memories and things I cant unbolt and just put on something else.

No offense; my point is, if you swap a 4.0L you will have a not so great installed 4.0L (I am assuming this is his first engine swap; I could be wrong here) when you could just have a factory installed 4.0L for about the same. As a result, I just feel it's better, if you are going to go through all the effort, to just get a better engine so that the effort provides greater returns.

 

[O_M_Jeep]

In principal I really agree with you, and I'm sure thats the best course for some, I really like my 2.5, but I have to admit mine is in no way a DD, and at this point I can't see myself parting with it.

 

[jfrabat]

In principal I really agree with you, and I'm sure thats the best course for some, I really like my 2.5, but I have to admit mine is in no way a DD, and at this point I can't see myself parting with it.

I agree; mine is the same situation. And I may just end up changing the engine sometime in the future, but it would not be a 4.0L. In my case, I would go to a V8 (which, of course, means new transmission, TC and axles and all the related headaches!).

 

[quicksand97]

Thats correct, always on with a kill switch inside, I used a switch with a flip up cover so I would notice if I forget to turn it back on, to do that you have to have the switch on the ground wire, not the positive wire to the relay, I'm at work now but I will post some pics when I get home in the am.

The swicth to the ground wire to the relay? Is that just to cut off the power to it. Or lets say the fan wont work without a ground right? Forgive me just trying to understand it to the exact detail. Yeah pics would be nice. Is it set up that way so that the swicth is down for the fan on possition?

 

[O_M_Jeep]

The pics, sorry it took so long

In this pic the lights would be the fan,

Green the switch. So, to make it always on, the green wire goes to a 12 volt source that turns on with the ignition (not the acc side, just the running side).

the yellow still goes to the battery because thats what you need, clean strong power,

the ground on the relay is where you want your toggle switch, remember that the switch has to be on for to work, when the switch is off, the ground breaks and the fan shuts off, so if you have a shielded switch like this one, the switch has to be turned around so that its on when the cover is closed and off when up.

The fan has its own ground, this needs to be grounded as close to the fan as you can, mine is grounded to a bolt on the inside of the grill right outside the shroud, and you'll want to touch the wires to your battery before hooking it all up and make sure the flow direction, usualy the fan has a black and a yellow wire, on mine black is (+) positive and yellow is (-) negative

The fan I used was a little under $100 at O'Rielly (may be more in some places), its a Hayden 16" high flow fan and comes with everything to mount it, but not the 30a relay

I have had good luck with this fan crawling and off-road, this is the reason I dont use salvage yard fans, this happened on the trail in Moab, and the flames were about 3' tall and took a full 3 lbs extinguisher to put out.

Of all the ""get more power"" mods I have tried, this is the only one with a seriously noticeable difference. I dont think I made this look easy and it really is, I would reccomend taking the shroud off to attach the fan, just be sure to get it centered and test fit the fan to ensure it fits within the shroud. Happy trails.