2.5L performance?

[Josh95YJ]

OK, let me start by saying I have not dyno'd my Jeep, so everything I say is not backed up by data (it is from a theoretical point only).

Regarding the fan, in theory, switching from mechanical to electrical should result in some loss, so when the fan is actually on, it is less efficient than the mechanical fan when it's on. The good thing about the eFan is that (with the right controller), it will be off when it is not needed (say, when you are driving 30mph or faster). Also, the speed of the fan is independent fromt the speed of the engine, which means if you are rockcrawling in 4L, you can turn the fan on a full speed and it will cool a lot faster than the mechanical fan.

Now, to say I have noticed a drastic change when switching from mechanical to eFan would be a load of crap. Does it help? Yes. Is it a night and day difference? NO. Would I do it again? Yes. Does it free up some ponies? Yup. Will you feel them with the but-dyno? Probably not, but you will be less likely to shift down to 4th on the freeway. In my case, I did a prior run to see where I needed to downshift on an overpass in Miami, and with the eFan, I would not have to shift until higher on the ramp. Later, with the 62mm TB, I did not need to downshift at all... Of course, the test is not 100% scientific because it does not factor in the wind speed or the fuel weight (fuel tank at different fill levels), so keep that in mind.

As for the Flex-A-Lite, I have no gripe with them other than why pay $100+ when you can get something just as good for $30 (ford fan).

Now, regarding the TB, what you really want is no restrictions at all. This means as straight as possible piping from the filter to the TB with no restrictions (ie. the diameter is always constant). Now, the intake manifold can be opened to 62mm (I think even 63mm is still doable), and the 4.0L TB can be bored out to the same. TBS you can make your own or bore the one you have out to take maximum advantage. By the way, if it has that spiral thingy, that does nothing to help your HP... You want a SMOOTH surface...

As for the air pressure, I would not worry too much about that; in my opinion, the formula is simple: you need air, fuel and spark. For more power, you need more fuel. To burn more fuel, you need more air. The ECU will compensate, so more air and more fuel will give you more power at WOT only (something to keep in mind). By the way, I run a little higher pressure than most (46PSI) to compensate for the 62mm TB, cam and other doodads that I have on my rig...

As for the plugs, I have run the accel coil and the Screaming Demon ones; I have gapped my plugs at .060", and it still runs nicely, but I have also fried my coil, so I am now considering to lower the gap a bit (especially since I got a 600 mile road trip coming up; last time I made the trip, I ended up having to swap coils in the middle of nowhere at night under the rain! NOT FUN!).

I have been running that Accel coil (not the blaster) but ignition for awhile. I have to tell you though I have Accel Wires, NGK Plugs (I have only been doing mechanics at a shop for 4 years, after a 14 year Culinary degree and I had to Gap the NGK for the first time.) I don't know if I am getting proper gapping on them if you have some insite for me let me know the right way, the top over the kernal is covering a good bit that I don't know if its running across the gap tool right. I should have gotten the whole distributer too and not just rely on the factory distributer, cap, rotor,plugs, and wires, cause I'm even going through distributer caps as well as rotor, bad plugs, and some missing. But I havent found just a distributer cap which probably wouldnt solve that withou the whole Acell distributer correct? I have on the Airraid Cold Intake, and poweraid throttle spacer 62 mm but it has the grooves in it, I had no Idea that the flat made a better difference. Good quote taught me a couple things. I rarely have to go to fourth on the freeway I have the 2.5 as well, speed limit is 65 then I am usually at 70 or so tops higher though when needed to be, but If i hit a pretty good uphill on the freeway that vibration of being in a higher gear when should be lower slowly starts hitting. My question is would the full distributer upgrade make it pretty much even better than that cause when I go up to Camp to hunt and fish Im all through the mountains of NW Pa. of increase and decrease everywhereI may drive

 

[Josh95YJ]

O guess what I did the other day, sense i can not afford a electric fan right now and also been debating between electric or flex. I took a pair of tin snips and little by little cut down my factory fan. Very carefully sniped of the corners of each blade, about half inch measured both ways from corner. This is the corner closest to engine. Then I got brave and took a wide pair of pliers and slightly bent about quarter inch at corners to further reduce air drag as the fan rotates counter clockwise. The bend was slight, a hair less than a 45 degrees. To my surprise the little 4 banger seem to wind up alot easier and faster of the line and down the freeway, with less effort. My concern was I thought my temp gauge to going to run hotter, but it was running cooler. I am going to hold of on any electric or flex fan for now. Runs so easy and smoother I just might keep it the way it is. Ok sometimes I talk to much gotta go. My jeep has four angry squirrels under the hood, feels good. Catch you later fellow jeepers.

You should remeber though the factory parts put on are all compatible for the maximum performance and drivability of a bone stock jeep, you modified yours pretty good from what I read on yours but my concern of doing that is cutting into the fan could lead to some headaches screwing up more expensive parts of the motor, It's almost like using hockey pucks for a body lift, I have seen that and the ride was ****. just be careful cutting away at stuff or trying self thought upgrades with some of the factory parts unless your replacing something completely with the parts that are gonna run compatible with that 2.5 A for effort though...not knocking you brother just would hate to see a fellow Jeep Wheeler screw up something you put alot into

 

[quicksand97]

To JFRABAT as far as the Power spacer i have from gsppowerspacers has no air flow restriction, it has air blades that redirects the air flow, its called air wave tuning. They use air wave tuning in designing intake manifolds, direction, lenth, diameter size and smooth curves or sharp curves. Anyway works great. I guess it is like your air conditioner vent inside your car. Hey I have a question do you know what # injectors I have from factory in my 97 TJ? And is your 19# injectors a upgrade from your factory ones and what did it do for you. Did you have good results or marginal? Thanks for your input on the e-fan.

 

[jfrabat]

To JFRABAT as far as the Power spacer i have from gsppowerspacers has no air flow restriction, it has air blades that redirects the air flow, its called air wave tuning. They use air wave tuning in designing intake manifolds, direction, lenth, diameter size and smooth curves or sharp curves. Anyway works great. I guess it is like your air conditioner vent inside your car.

Regarding the power spacers, let's take a look at their claims:

The GSP Power Spacer is an extreme, unique, one of a kind throttle body spacer.

First off, they are not unique; these have been around forever... Open any Popular Mechanics or Popular Science mag, and you will surely find some of these in the last pages...

By raising your throttle body one inch, the GSP Power Spacer increases your plenum and helps your Jeep's engine to atomize your air/fuel mixture providing a better burn by leaving less unburned fuel in your manifold. This process puts your fuel to better use (combustion) which equals more horse power and torque output from your Jeep's engine.

Ummm... Last time I checked, ever since Jeep switched to MPFI, there is NO fuel in the manifold; the injectors atomize the fuel directly. So even if the Vortex effect did improve the atomization of the air/fuel mixture, the point is moot because there is no fuel there to atomize (plus I doubt any vortex effect will pass the 90* bend that happens right after the TB). I do buy the plenum space part a bit... I have seen some dyno charts that show that a smooth bore TB spacer is the one to increase the most power (test runs were done with no TBS, a Helix TBS - no wings like yours but the ones with the grooves on the sides - and a smoother out TBS).

To add to this equation, the GSP Power Spacer Air Blades force incomming air to twist and spin with even greater velocity optimizing your performance. With this efficiency you can expect a one to three mile per gallon increase in your fuel economy... that is of course if you can keep your foot off the pedal.

Simple question; what flows faster? Air going straight or air that is spiraling? The engine will ingest the same amount of air, but which will move faster? If you look at race cars, the air intake is always as straight as possible to avoid any turbulence in the air, which would slow down the flow of air because it would interfere with the laminar flow...

Anyway, if you are happy with it, good for you. I think you would be surprised if you ran a dyno with and without the TBS, but that's OK.

Hey I have a question do you know what # injectors I have from factory in my 97 TJ? And is your 19# injectors a upgrade from your factory ones and what did it do for you. Did you have good results or marginal? Thanks for your input on the e-fan.

Mine is an upgrade, but it would not be an upgrade for you because the YJ and TJ injectors are different. IIRC, the TJ are 22# or so... Would have to check to be sure, though. Another choice to improve atomization is to raise your fuel pressure (a couple of places sell adjustable FPR). But unless you can take advantage of more fuel (cam, 1.7 rockers or something along those lines) I would not go in that direction... Go with the simpler mods first.

Anyway, if you need some reading material about injectors, may I suggest this page:

http://4bangerjp.com/forums/index.php/topic,3479.0.html

Felipe

 

[dos0711]

If you want more zip out of your 4 banger, re-gear is the most definitive mod. It guarantees results. Everything else is barely felt.

 

[Bounty__Hunter]

Quicksand, I've got some 62mm throttle bodies on hand if you're interested, as well as smooth-bore 62mm 1" spacers as well. Very reasonably priced compared to retail. They will blow that winged thingy you have out of the water.

And no adjustable fuel pressure regulator for you and your TJ, that's a YJ thing.

 

[jfrabat]

If you want more zip out of your 4 banger, re-gear is the most definitive mod. It guarantees results. Everything else is barely felt.

While I cannot say this is wrong, regearing is also one of the more expensive mods. But to be honest, the expensive mods (regear, turbo, and supercharger) are the ones that REALLY make a difference. Like DOS said, the other mods you will not really feel (it's more of a "I dont downshift to 4th like I used to" thing rather than the "Whao, this thing is really quick" type of response).

And no adjustable fuel pressure regulator for you and your TJ, that's a YJ thing.

Keep forgeting TJ's dont have a return line...

 

[quicksand97]

Thanks allot for all that info and input guys, just goes to show you how some things work for others and not for someone else. My concern as far as a 62mm TB would be will I loose torque and would it match the top of my manifold?

 

[jfrabat]

The intake manifod is about 60 or 61mm; you can always open it to the correct size, but the 62mm (or 63mm) TB will bolt right one (there will just be a bit of a lip there to cause some turbulence, but you should still gain a lot of mid thorttle response).

 

[superj]

you can gain velocity by creating a venturi but go with the bored tb, it is a feelable mod on a 4.0. sorry i cannot say if you can feel it on a 2.5. it was a night and day difference on my cherokee

 

[abe]

check this product out i just bought one still waiting on it to come in but ill let u guys know if it was worth it. Jeep 62mm/63mm 4.0L & 2.5L 1991-04 Ported Throttle Body: eBay Motors (item 370322497378 end time Oct-16-10 21:33:00 PDT)

 

[abe]

ok i got the the in the mail on wed installed it on thurs. after work. yeah it was that simple. i love it big difference in get up and go on the highway i notice I'm not shoving the throttle to the floor to keep up @ 75mph. I do have a stick and i noticed that the revs do not drop off as fast as they used to. i am very happy. i have a k&n and a flowmaster series 40 muffler. lol All i need now is a electric fan and i will b done for mods. then off to the body shop for some much needed TLC.

 

[jfrabat]

All i need now is a electric fan and i will b done for mods.

Yeah, that phrase goes right next to "I swear I'll never drink again"...

 

[abe]

Yeah, that phrase goes right next to "I swear I'll never drink again"...

Yah herd that b4, and used it. Also attached is usually. "I got this."

 

[quicksand97]

Here is a question, which coil is better the accel or the screaming demon. I currently run a accel coil and wires with NGK plugs gapped at .037. What is the biggest gap I can run, or somewhere in between? What is your opinion on Live wires which are said to be 10mm with a low ohm resistance.

 

[jfrabat]

I have run both coils, and have burned both... But the screaming demon lasted a lot longer. I also run the Live Wires, and I like them a lot. If I were to do it again, I would go with performance distributor's complete setup again.

 

[quicksand97]

Sound good I will probably get the live wires, and continue running it with the accel coil. I just do not know how big a gap to run without going over board.

 

[Bounty__Hunter]

PD says you can run .065" with their coil.

 

[quicksand97]

Thanks I will try the PD wires, By the way Mr Bounty Hunter do you carry any regular 4.0L TB. I currently run a home brewed TB that is 61mm on top and 51mm on the bottom side, it sits on top of a spacer that is 60mm on top and 55mm on bottom. My manifold is bored out to 56mm. Seems to work pretty good with this funnel affect as it tapers down. I believe it creates more presure. My concern is if I run to big of a TB I might lose torque. My 4 banger is very sensitive to any changes, I have a ram/cold air set up that is adjustable as far as letting air in from outside. When I let to much air in I lose torque. Right now it is fine tuned thru trail and error as far as air coming in. I close it a lil and lose power, I open it to much and like I said I lose torque. Thats why I have concerns about a change to a bigger TB than what I have.

 

[Bounty__Hunter]

Yes I have 4.0L TB's as well as the 62mm units. If you're interested, I'll throw one in the blast cabinet and it'll clean up like new.