Topic: Suggestions for cheap power upgrades.

[YJyoungster]

Alright boys and girls, I'm looking to get some more horses out of my little 94 yj 4 banger.

I've already put a 4.0l throttle body in and am thinking about throwing in some ford #19 injectors, and maybe doing an electric fan conversion.

Tell me you have done in order to get more punk out of your 4 banger. Yeah... and a turbo or super charger is way out of my price range.

[VA_YJ]

Tell us about your tires and gearing.  That can have a big impact on performance.

[YJyoungster]

stock 4.10 and the equivalent of 30 inch tires. stock suspension, I plan on upgrading power now before puting a lift and bigger tires on.

[jfrabat]

You want cheap upgrades or something you can feel?

The best upgrade is regearing (jump to 4.88 if you are going to make the investment; 4.56 is just too close to 4.10 for it to be worth the money it takes).  But it is no cheap.

Of course you can also do a complete engine rebuild alla YJMechanic (look at his post in projects), but again, not cheap... although cheaper than a supecharger (not sure if cheaper than a turbo, though, but I would think probably more reliable).

Other than that, the other mods will have small impact, although together they do make some reasonable increments; just dont expect your pants-dyno to feel it off the line; you'll feel it more when you will not need to downshift when driving against the wind or going uphill.

In my opinion, e-fan will free up the most horses and it is cheap.  19# injectors are also a good idea, but think about the filter as well.  Airflow (both intsake and exhaust) can change the engine's performance.  Ignition is another thing you can look at.

Felipe

[YJyoungster]

Yeah I'm really thinking about doing the electric fan conversion. I know the taurus fan works well, what would be some other fans that i could use?

[dexetr30]

Volvo S80 turbo fan. Almost the same install procedure as the Taurus fan.

[cletz97]

question about throttle body spacers...do they actually help? i was gonna get a 62mm throttle body and was wondering if i should go for the spacer cause i see them everywhere.

[jfrabat]

question about throttle body spacers...do they actually help? i was gonna get a 62mm throttle body and was wondering if i should go for the spacer cause i see them everywhere.

I have read mixed reviews on this; I have one on, but stay away from those "vortex creating" TBS, as you want as smooth an airflow as possible.  I do know the TBS work with carbs, but with EFI, it is up for debate...  Anyway, you can find some cheap ones on eBay that include the gaskets, and that is what I got...

[rubberducky]

I have an 05 tj, and my brother has the same. We go through stages of adding stuff to see if it works. So i know a Throttle body spacer, jet chip, and a cone air filter on the intake (right on engine not on long tube) works. We would add a part to one jeep and then compare to the other. Last hunting season we would travel to the lease about 300 miles away. God i love Texas.  I would pull a trailer with 31's on the jeep. and the trailer would have camping supplies, 2-300 lbs of deer corn and my set of 33's. we would cruise around the same speed. He only had me on acceleration once we got into the mountains. but he is running factory street tires, and both of us have 3.73's. Even last weekend I pulled a round bail of hay up to the ranc with my Tj, Got about 14 mpg doing about 70. ( a round bail of hay weighs about 500 lbs or so, and is 4ft wide by 6ft tall, for those that don't know). I did try to dump my exhaust (the bolts broke on a trip) man it was annoying, did not help the power, because the lack of back pressure put the power band to far into redlining. so i didn't bother pursuing it further.

[st.chevrolet]

One of the most overlooked power upgrades that is relatively cheep and easy, would be to buy a good set of "low resistance" plug wires like MSD 8.5mm Super Conductor Wires. You will find if you check with a volt meter that most vehicles come with "high resistance" wires somewhere around 5000 ohms per foot, as apposed to about 50 ohms per foot in the low resistance wires. Needless to say its a simple upgrade that does make a difference.   
The Ford Taurus fan also works great as a power/mileage upgrade. Before I added a turbo to my engine that is very reliable and has been a daily driver for almost a year and a half now. I ran a Taurus fan, 4.0L throttle body, K&N open element filter/intake, MSD wires, and 19lb injectors. The set up worked well but in the end it is still just a natural aspirated 4banger, for a noticeable amount of power your gonna need to spend more then just a few bucks. But the cheep upgrades that others and myself have all passed on are a good start.

[blacknblue]

Not to discourage you, but I would say save all the money you would spend on upgrades for the 2.5 and swap in a 4.0 or better.  The typical modifications listed here will make driving a four banger a little more tolerable...but in the end you are only working with around 123 hp on a stock 2.5.  You can probably tweak out 130-140hp but to get up to even 150hp would require a turbo or supercharger.  A stock 4.0 is around 180hp and responds a little better to modifications than the 2.5...you could easily reach 200hp with a few select mods.  I know this is opening a big can of worms, and I love my 2.5 don't get me wrong, but in reality it comes down to dollars per horsepower...how much horsepower can you actually gain for the amount of money you spend.  There is no replacement for displacement, if you want more performance...get a bigger engine. 

[chardrc]

Not to discourage you, but I would say save all the money you would spend on upgrades for the 2.5 and swap in a 4.0 or better.  The typical modifications listed here will make driving a four banger a little more tolerable...but in the end you are only working with around 123 hp on a stock 2.5.  You can probably tweak out 130-140hp but to get up to even 150hp would require a turbo or supercharger.  A stock 4.0 is around 180hp and responds a little better to modifications than the 2.5...you could easily reach 200hp with a few select mods.  I know this is opening a big can of worms, and I love my 2.5 don't get me wrong, but in reality it comes down to dollars per horsepower...how much horsepower can you actually gain for the amount of money you spend.  There is no replacement for displacement, if you want more performance...get a bigger engine. 

in the mean time the electric fan conversion will benefit any motor you end up having...

[blacknblue]

     I forgot the title to the this post was for CHEAP power mods...so I apologize for suggesting an engine swap...which can be rather costly.  My first engine mod was fairly cheap, a drop in K&N air filter ($45), then I went with a Firepower ignition...includes a cap, rotor, coil, and low resistance wires ($100), a set of E-3 plugs ($15).  This woke up the engine rather nice...best mod for the money besides the 4.0l throttle body.  You could over gap your plugs with the hotter coil in the Firepower ignition kit,  I did and it ran fine but later decided to switch to different plugs that you really cannot gap.   Overgapping of plugs is a cheap...well actually FREE way to increase performance...but it requires the ignition kit with the hotter coil.
     Next up would be a cat back exhaust system...but here is were you are going to have to spend some cash.  I went with a Banks header and a Monster exhaust system.   Total cost on parts was around $850...shop labor will vary.  After you free up the back end, you could go with a cold air intake.  I have plans to instal a snorkel this spring which will force cold clean air in to the engine...not to mention keep water out....this is probably gonna run around $400 with me doing the work.  I also run a Stage 2 Jet chip...this is a good mod for those who have an auto trans...because it creates new shift points. Not cheap $250 but easy to install....electical tape the hell out of it to prevent water from getting in it. 
     I would also recommend running Royal Purple fluids.  I gotta get back to work.
Kevin

[mastermoparman]

good info here. interested in why no one recommended a header?

i run a 2.5 because its almost 300 pounds lighter and there is plety of room between the radiator and grill to hide a winch

[blacknblue]

I run a Banks torque tube header and it works in tandem with the Banks Monster exhaust really well.  It does free up some top end and I could tell the difference at highway speeds.  The header and the muffler makes my 2.5 sound really mean...like four angry squirrels who have'nt eaten in a week.