Power hungry 4.0: how to give it what it wants?

[Cumsterdump]

i want to make my tj more peppy and i know this is gonna send some of yall into a frenzy but entertain me here please.

i don’t want to regear yet as my 3.73s are great for my use case, and i want to keep the 4.0 platform. im a bit of a purist and one of the reasons the TJ is so infamous/why i love it is due to the killer engine so i would feel wrong changing that.

who has made a name for themselves making these four liters make some output. like newcomer racing

yes the platform isn’t good to build off of, but i want to know who said watch me and made it work anyways.

i understand it’s not an effective platform for making power but im willing to spend MY money on MY jeep to do it

 

[KennethS]

I have a classic muscle car and have been on respective internet forums for years. Any time someone asks about increasing performance, the answer is the best bang-for-the-buck is lower gears. I’ve regeared my car twice over the past 40 years and each time it felt like I added 50 more horsepower to the engine.

 

[macleanflood]

Start here and watch this series...

-Mac

 

[ColoJeep]

I have a classic muscle car and have been on respective internet forums for years. Any time someone asks about increasing performance, the answer is the best bang-for-the-buck is lower gears. I’ve regeared my car twice over the past 40 years and each time it felt like I added 50 more horsepower to the engine.

^^ THIS ^^ 100% , gears are a bargain for increased performance .

 

[Chris]

LS swap

 

[L J]

@jjvw put a supercharger on his 4.0. He may offer some insight.

 

[jjvw]

@jjvw put a supercharger on his 4.0. He may offer some insight.

Regear for the tire size before adding boost.

 

[TJ Jim]

Smaller tires

 

[speeding_infraction]

Smaller tires

 

[Ctdriver86]

Start here and watch this series...

-Mac

Or here,

https://wranglertjforum.com/threads/dyno-testing-bolt-ons-on-the-4-0.79004/

 

[Cumsterdump]

I have a classic muscle car and have been on respective internet forums for years. Any time someone asks about increasing performance, the answer is the best bang-for-the-buck is lower gears. I’ve regeared my car twice over the past 40 years and each time it felt like I added 50 more horsepower to the engine.

thanks for the recommendation but like i mentioned in my post that’s not what im looking for. i am long past bang for buck i want to spend to build a motor

 

[GoldenGorilla]

I think your definition of power or pep does matter here. As does understanding what your specific goals are. You probably need to understand the performance characteristics of the 4.0L.

The dyno power series addressed a range of power adders while keeping the stock displacement and keeping costs low-ish. But none of them fundamentally rewrote the bottom end of the curve below 3000 rpm. To do that, you have to go forced induction or stroker, and you have to get it tuned or learn how to tune it yourself.

Why do you want to stay with 3.73 gears?

I'm not going to jump on that bandwagon. Gears don't change the engine's power curve or increase it's output. They change where you are on that curve, which helps in alot of cases. The JL Rubicon folks are general happy with their stock 4.10s up to 35s and they come stock with 33s. There is a reason most recommend 4.88s with 33s here. The 3.6L Pentastars have a broader power curve, more gears in the transmissions and significantly more power at all rpms, which is why this works.

What specifically does more power mean to you?

What compromises are you willing to live with?

What are you not willing to live with?

Tuning support is HPTuners MPVI3.

The other stoker people to talk with are Clegg and Russ Pottiger for parts or S&J, Titan or Golen for a built 4.6L.

The forced induction options are a bit scattered these days. @Jezza has a turbo kit. 505 Performance lists them, but may not stock them. I think Boosted Tech still has options for the 4.0L. I'm not sure if any of the others are left.

 

[speeding_infraction]

thanks for the recommendation but like i mentioned in my post that’s not what im looking for. i am long past bang for buck i want to spend to build a motor

Then talk to newcomer racing and @Flyin' Ryan Performance
Newcomer racing TJ:
https://www.facebook.com/NewcomerRa...this-jeep-after-a-fresh-tune/852085567475581/

 

[Obi-Wan]

i want to make my tj more peppy and i know this is gonna send some of yall into a frenzy but entertain me here please.

i don’t want to regear yet as my 3.73s are great for my use case, and i want to keep the 4.0 platform. im a bit of a purist and one of the reasons the TJ is so infamous/why i love it is due to the killer engine so i would feel wrong changing that.

who has made a name for themselves making these four liters make some output. like newcomer racing

yes the platform isn’t good to build off of, but i want to know who said watch me and made it work anyways.

i understand it’s not an effective platform for making power but im willing to spend MY money on MY jeep to do it

I too am a purist. The 4.0 is a great engine and pairs with the TJ incredibly well.

With that being said, I wish I had put the 5.3 LS I have in now 10 years ago. The difference is above and beyond what the 4.0 could give me.

 

[ColoJeep]

Then talk to newcomer racing and @Flyin' Ryan Performance
Newcomer racing TJ:
https://www.facebook.com/NewcomerRa...this-jeep-after-a-fresh-tune/852085567475581/

Yup , It is only about $ 36.67 per lb. ft. of torque . on the 5.0 " MEGA-TORQUER . Building an engine is FUN ! However one must remember the old adage ,
" There is no substitute for Cubic Dollars " .

 

[BlueC]

i am long past bang for buck i want to spend to build a motor

Do you? Do you know the associated cost, and how does that play with your budget?

 

[NashvilleTJ]

Performance is always about the entire package. You can't simply address one issue and expect good results.

I ran a supercharged I-6 for years in my rig. It made 300 ponies and 400 torque. 100% reliably. I ran 4.88's on that setup with 35's for a while, and even with the small tires it really needed more gear.

JJ currently runs a SC on his rig and makes good numbers as well. Listen to his advice. There are a bunch of us here who know about making power.

Take my word on this - there is absolutely nothing you can do to the 4.0 which eliminates the need to address the gears when running bigger tires. Period. For good performance on our rigs, you need to address both. There is no short cut.

No matter what you do to the engine, invariably when running bigger tires you will be disappointed if you do not address the gears as well.

 

[speeding_infraction]

Yup , It is only about $ 36.67 per lb. ft. of torque . on the 5.0 " MEGA-TORQUER . Building an engine is FUN ! However one must remember the old adage ,
" There is no substitute for Cubic Dollars " .

Cubic dollars, that's a good one. I posted newcomer because of this:

i want to spend to build a motor

I figured newcomer would be a good place to spend it

 

[NashvilleTJ]

LS swap

I'd give anyone else here grief about this statement, Chris, but your ability to completely eliminate my forum existence at the touch of a key keeps me from doing so...

 

[Chris]

I'd give anyone else here grief about this statement, Chris, but your ability to completely eliminate my forum existence at the touch of a key keeps me from doing so...

Listen, all roads lead to V8