Easy Power Mods for Jeep TJ 4.0 Thread

Jerry Bransford said:
Then by all means you should convert your fan to electric. It's your Jeep, do whatever you want to do with it. I and others voiced our opinions and they weren't convincing to you so it's time for you to go for it. Good luck.
Click to expand...

Jerry Brannsford in my book is the gossip for Jeep Wrangler knowledge and sound advice.
I like to address the video I posted is another youtuber with a wealth of knowledge regarding parasitic drain on engine horsepower. Fryberger from Motor Trend/ Roadkill basically shows how OEM fan blades killed 25lbs torque and 30hp running a OEM fan on his V8. Also in the same video running correct oil levels is another parasitic power loss. Which is new to me and something I wanted to pass along to other readers. The thread is a learning lesson what works or doesn't.
I can say my Jeep ran better and seems to have more horsepower when I changed my oil, diff oil, t-case oil and tranny fluid.
I think this is a good example for parasitic drain over new vs used oil.

So Jerry please do not take my follow up responses as questioning your authority I find all your advice extremely sound.
I thought other readers can learn about parasitic power loss can get back HP.
 
Last edited:
H
SkylinesSuck said:
Because I needed clearance for the big shiney thing.


View attachment 216095


It makes more sense for BMW guys who run their engines higher in the rpm range and care how fast they accelerate. It will not help one bit with more twist at your rear axles helping you go up a hill at 50mph unless you were already just barely making it near redline in 2nd gear.

E-fans ARE more efficient, help with throttle response (maybe), and increase top end hp (which is related to but not the same as torque). None of this will help you going up a hill on the highway. I have had an e-fan for like 10 years, do not have a bypass switch for water crossings, and have never once desired one. I think it's a made up scenario almost nobody ever encounters. It's a theoretical possible plus though.

The possible downsides are it not cooling as well and reliability issues. I have dealt with both. If I could fit a stock fan setup I would.

All of this coming from a guy that enjoys treating his TJ like a race car. I am that guy and I'm telling you avoid the fan. If you are bound and determined to blow money on bolt on power mods like my dumb ass, there are a lot better things to blow it on. None of them will help you make go up a hill in 5th any better though. Gears, or go big with a power adder, stroker, or motor swap.
Click to expand...
How do you like the windstar intake mod?
What's the point again of doing that mod?
I see your running a new aluminum radiator. I have to say people here have expressed many aluminum radiator crack and leak after 2 years.
I'm here to confirm my Champion aluminum radiator leaked after two years/30k miles. I'm hoping my second wont leak. Only saving grace is Champion is life time warranty.
 
Kaptainkid1 said:
H
How do you like the windstar intake mod?
What's the point again of doing that mod?
I see your running a new aluminum radiator. I have to say people here have expressed many aluminum radiator crack and leak after 2 years.
I'm here to confirm my Champion aluminum radiator leaked after two years/30k miles. I'm hoping my second wont leak. Only saving grace is Champion is life time warranty.
Click to expand...
This is my second champion radiator. First one leaked. Thia one is starting. They did replace the first under warranty. I think next time I am going to chance a stock Mopar rad and find a factory fan setup to put back on. Not sure it that will be able to cool my stroker, but I will probably find out this summer.
 
I'm surprised no one has mentioned weight reduction. Based on weight reduction, I'd guestimate 100 lbs. is equivalent of gaining 5 hp?
 
That is a ballpark estimate based on the way weight affects acceleration over roughly a quarter mile. Again, not going to help the way your guy's think it will. Might help your quarter mile time drop from a 19 secund pass down to a 18.9 secund pass lol.
 
So the fan idea has been covered. The 'drain a quart of oil' is even possibly worse. The 'go fast boys' that rev the 💩out of their engines can possibly pick up a few ponies by doing this. High crank speed will tend to whip the oil in the pan. That oil wants to cause drag on everything from the piston rings down. But we aren't spinning 8,000 rpm in a TJ. Hell, rarely see over 3,000 rpm for more than a minute. And those boys are keeping their engine nice and level. All oil down in the bottom of the pan, next to the oil pickup. Jeeps don't. They climb up and down steep slopes, lean sharply both directions, all at little more than an idle. You want that quart in there to help keep the oil pump pumping in all the different angles that the machine drives over. Take out a quart and you will, and I mean will, start to get cavitation in the oil system. All the air and bubbles is not what bearings and rings want to have. If anything i would ad a half quart before a tough trail to make sure the oil pickup has a good reservoir of oil to suck up.
Those silly TV shows are made for their silly TV audiences. Not actually for people that actually understand how and why a vehicle should be modified. They depend on their sponsors. And they try to sell the sponsor's stuff.
 
  • Like
Reactions: chad
I just watched the stock/4 hole/12 hole video for as long as I could stomach it. That guy really doesn't know the definition of "exponential".

I pulled all of my injectors and had them cleaned, and replaced one with a new stock injector. Definite improvement in the smoothness of my ride (because of the failed injector being replaced).

By the way, less weight absolutely helps and in all ways, including offroad, to a point.
 
sierradmax said:
I'm surprised no one has mentioned weight reduction. Based on weight reduction, I'd guestimate 100 lbs. is equivalent of gaining 5 hp?
Click to expand...
Funny, on one of the Harley forums a guy asked about how to get more power for little money. The answer was go on a diet. I wasn't the guy that asked but took it to heart and lost weight. Definitely help both on and off the bike.:cool::cool:
 
  • Haha
Reactions: RipSteakface
Acceleration vs tq required to go up a hill are two different things. Weight vs the aerodynamic force required to push our barn doors through the air are two different things. Weight reduction will help, but your returns will diminish rapidly the faster you go. If you are having trouble going 70mph in 5th down the highway, losing 200lb isn't going to help a lot with that. Making it while going 35mph up hill though? Sure, maybe a bit. How fast you get to 35? Yes, very much.
 
  • Like
Reactions: Ephry73
adding nitrous will get you a few more ponies. i'm thinking of doing this so i can run with the guys on street outlaws and get my jeep on t.v. show !!!! 🤔
 
  • Haha
Reactions: Ephry73
chad said:
I’m looking for a way to make mine pop and shoot flames out the exhaust!
Click to expand...
we had a guy at work, aircraft mechanics at atl airport, that had a old piece of junk skylark (if i recall) had airplane pieces and parts glued and screwed all over it. had a sticker "dont laugh because your daughters in here" and "honk if you see parts falling off ". anyway he ran the exhaust out the trunk, piped in a propane tank and wired a spark plug to it. he'd fire that thing off when we got off about 11pm and the security guards would go nuts ! damn thing would shoot flames 8-10 ft.
 
Last edited:
  • Haha
  • Like
Reactions: SkylinesSuck and chad
SkylinesSuck said:
This is my second champion radiator. First one leaked. Thia one is starting. They did replace the first under warranty. I think next time I am going to chance a stock Mopar rad and find a factory fan setup to put back on. Not sure it that will be able to cool my stroker, but I will probably find out this summer.
Click to expand...

If you run the stock mopar radiator and the stroker motor can't maintain cooling with stock fan.
Would you install a push fan and uses water wetter in the cooling system?
I found water wetter help keep my KLR650 stay cool. Water wetter was mod a lot riders recommended. It worked well for me. I'm assuming it can translate to Jeep engines too. What's your opinion?
Does your engine block run hotter with the new stroker motor set up? Did you experience heat soaking issues with the new set up? I see your wrapped your injectors. I was wondering did the stroker motor exacerbate the heat soak problem of the 4.0l 3 and 4 injectors..
 
Last edited:
My cooling system experience has been....complicated. When I first installed the stroker with the stock radiator, it ran fine except going up long grades at medium speeds (45-55 mph). I assume it's because the motor was able to make more power & heat because stroker. Idle or high speed driving was fine. Trail was fine.

I installed this big honkin aluminum radiator with hopes of it being overkill and never having a cooling issue again. It seemed great at first. No issues going up long grades and getting hot now. The one area I do have an issue is idling for long periods with the a/c on. It will slowly creep up over 10-15 minutes of idling. I don't ever let it go past 225* testing. I have upgraded the e-fan twice and now run the meanest fan that will fit. I have always run a shroud. It's gotten better but not fixed. I also added a little 10" pusher fan (that was this fall so no chance to test it in hot weather yet). I am guessing the e-fan(s) can't move enough sure through that thick of a radiator at idle with the a/c going. This is my second champion and it's leaking again. I am eventually going to try a Mopar factory unit with e-fans hoping the original rad was just older and not very efficient. If that doesn't fix it, I'll look for a stock fan setup to try. I need to remove the current rad for another warranty attempt anyways. I'll keep everything until I settle on a setup.

Hopefully the new Mopar stuff can keep up with my stroker this time. I don't want to have to choose between driving up big hills or leaving the family in the Jeep with the a/c going while I run inside the grocery store.
 
Oh yeah, I've used water wetter also. No noticable difference. I did run a water spray system on my Skyline. I shouldn't need and don't want to mess with that on my Jeep.
 
On the injectors, heat soak, hotter block, etc., I didn't notice a difference at idle. I did get the heat soaked injector issue but that was more because of the header and newer style intake I believe.
 
Top Bottom
Back