3.7 is a dog....Need more Power!

[Katmandu]

What can be done to get more power out of a 3.7 ? Not interested in turbocharging, supercharging, nitros or gear changing.

Just looking for some more gusto from the 3.7.

 

[first&lastKJ]

V-8 ?

 

[Dave]

If you need power and you want a Jeep, you need an SRT8 Grand. The one I drove had plenty of power anyway. Even the small V-8 has power. The 3.7....not so much.

Anything you do to the 3.7 is not going to make much difference so don't waste your money trying to make it what it isn't.

Just my opinion.

Dave

 

[CzarKJ]

How old are your plugs? Those could cause a lack of power. Also adding a performance exaust gave me a little extra, not a ton but some.

 

[QuickSilver]

You could try a canned or custom tune using something like the DiabloSport Trinity Tuner (and yes, they do build one for the Jeep 3.7L V6). But be advised the power increase tunes usually come with a tradeoff such as decreased MPG coupled with a requirement for higher octane fuel.

 

[tjkj2002]

Re-gear to 4.10's,the only sure fire way to get a performance increase.

Tuners,intake,and exhaust will cost just as much as re-gearing and give a fraction of the gain.Re-gearing also gives you more low end punch were as tuners and all that is all high end(4000rpm's+ only).

 

[Katmandu]

How old are your plugs?

About (18) months old. My Lib only has 6,900 miles on it.

 

[Katmandu]

You could try a canned or custom tune using something like the DiabloSport Trinity Tuner (and yes, they do build one for the Jeep 3.7L V6).

But be advised the power increase tunes usually come with a tradeoff such as decreased MPG coupled with a requirement for higher octane fuel.

I recently traded in a 2012 Mustang with a 3.7 V6 (DOHC, direct injected, VVT...way different engine than the dinosaur in the Liberty)..... I put a canned tune (SCT SC3), CAI, cat-back exhaust and woke that thing up BIG TIME ! At least a 20-25HP increase. My Highway MPGs actually increased substantially. 32-34 MPG Highway consistently (2.73 rear gear). No BS.

I'm not expecting all that from the Liberty dinosaur 3.7 pushrod in anyway shape or form, but I would really like it to have a bit more gumption!

So just how good are these canned tunes on the Liberty's 3.7 ?

 

[tjkj2002]

I recently traded in a 2012 Mustang with a 3.7 V6 (DOHC, direct injected, VVT...way different engine than the dinosaur in the Liberty)..... I put a canned tune (SCT SC3), CAI, cat-back exhaust and woke that thing up BIG TIME ! At least a 20-25HP increase. My Highway MPGs actually increased substantially. 32-34 MPG Highway consistently (2.73 rear gear). No BS.

I'm not expecting all that from the Liberty dinosaur 3.7 pushrod in anyway shape or form, but I would really like it to have a bit more gumption!

So just how good are these canned tunes on the Liberty's 3.7 ?

The 3.7 is not a puch rod engine,it's a SOHC engine.

Tunes generally will not do much if anything in a gas engine that is not direct injection(why turbo diesels see so much gain) without internal engine mods.


I have a stock 3.7 in my KJ and it weighs over 6000lbs and turning 35" tires and below 3000' in elavation I practically do a burnout everytime I take off since at 6200' you loose major power.Gear ratio,gear ratio,and gear ratio is key,I run 5.13's.

 

[QuickSilver]

You could try a canned or custom tune using something like the DiabloSport Trinity Tuner (and yes, they do build one for the Jeep 3.7L V6). But be advised the power increase tunes usually come with a tradeoff such as decreased MPG coupled with a requirement for higher octane fuel.

I recently traded in a 2012 Mustang with a 3.7 V6 (DOHC, direct injected, VVT...way different engine than the dinosaur in the Liberty)..... I put a canned tune (SCT SC3), CAI, cat-back exhaust and woke that thing up BIG TIME ! At least a 20-25HP increase. My Highway MPGs actually increased substantially. 32-34 MPG Highway consistently (2.73 rear gear). No BS.

I'm not expecting all that from the Liberty dinosaur 3.7 pushrod in anyway shape or form, but I would really like it to have a bit more gumption!

So just how good are these canned tunes on the Liberty's 3.7 ?

I was mistaken in my initial post. I thought there was a tuner for the 3.7L and there is, but it's from Hypertech and only for 2004 and later KJ's. DiabloSports does sell a tuner for Jeeps, but for the 3.8 and 4.0 engines only. My apologies for the misquote.

 

[tonyrivera02]

Well, I have put these myths to rest by spending the time and money and see for myself if in truth the 3.7L engine is capable of more power/torque/mpg.

I spent $780

JBA SS short headers
Dynomax UltraFlow
K&N Cold Air Intake
Fastman ThrottleBody
Autolite Iridium XP SparkPlugs

After upgrades, multiple tests were run for 2 weeks and these are the results...

+ 19hp
+ 11lbs/torque
+ 0.36MPG/city - 0.80MPG/Hwy

So, I will say that even though there is no great gain overall, it sure sounds better, runs much smoother and therefore no regrets on the investment.

PS. I only use Royal Purple products for the engine, transmission, transaxle and differential. Also the $780 did not include labor charges as all labor was done by me.

 

[tonyrivera02]

I want to add that you can't compare a 305hp DuraTec V6 with Twin-independent Variable Cam Timing (Ti-VCT), true dual exhaust and a curb weight of 3401lbs (+/-) with a (*1999-It hasn't change since) 210hp SOHC PowerTech V6 and a curb weight of 4100lbs (+/-).... sport car vs. SUV... NOT even close to same category

 

[tommudd]

Well, I have put these myths to rest by spending the time and money and see for myself if in truth the 3.7L engine is capable of more power/torque/mpg.

I spent $780

JBA SS short headers
Dynomax UltraFlow
K&N Cold Air Intake
Fastman ThrottleBody
Autolite Iridium XP SparkPlugs

After upgrades, multiple tests were run for 2 weeks and these are the results...

+ 19hp
+ 11lbs/torque
+ 0.36MPG/city - 0.80MPG/Hwy

So, I will say that even though there is no great gain overall, it sure sounds better, runs much smoother and therefore no regrets on the investment.

PS. I only use Royal Purple products for the engine, transmission, transaxle and differential. Also the $780 did not include labor charges as all labor was done by me.

Problem is most things were a waste like the K&N filter, and throw those spark plugs away and just install good copper cores , much better and the engine will run better

 

[colorado76]

Copper Core plugs are the way to go, I tried a few different platinum plugs. They all ran like crap, so I just use the stock NGK plugs. And for K&N filter, I have a ( AKA) Cold Air Intake = Hot Air. But I like it anyway its eazy to wash and reuse. I also have a Dynomax Muffler and I like the way it sounds, but I guess want little bit of horse power we gain is not worth the price we pay. But we all have our own ideas and passions for our rides.
I want to regear next, got to save for that's lots of $$$$$.

 

[Katmandu]

Well, I have put these myths to rest by spending the time and money and see for myself if in truth the 3.7L engine is capable of more power/torque/mpg.

I spent $780

So, I will say that even though there is no great gain overall, it sure sounds better, runs much smoother and therefore no regrets on the investment.

Also the $780 did not include labor charges as all labor was done by me.

$780 = 150 Pizza and Beer dinners to me!

 

[CzarKJ]

$780 = 150 Pizza and Beer dinners to me!

5.2$ a meal??? Where do you find good beer that cheap???

 

[profdlp]

5.2$ a meal??? Where do you find good beer that cheap???

Maybe it's not "good" beer. :mexsmoke:

 

[tommudd]

Maybe it's not "good" beer. :mexsmoke:

Or good beer and cheap Pizza :shrug:

 

[Katmandu]

Or good beer and cheap Pizza :shrug:

Ding! Ding! Ding! We gotta Winner! :>)

 

[Marlon_JB2]

I know quite a few people that are more than happy with eating cheap $5 Hot - N- Readys and cheap $0.99 tallboys...