4.0 improvements

[badbronc92]

Hey all, i have an 03 Ranger FX4 with the 4.0L. Originally i was driving it at 300 feet above sea level, now i'm out in colorado and am cruising at around 7000 ft. You can imagine the performance difference. Anyways, i'm wondering what are some good modifications to perform on this engine so i can get a little more out of it. I'm looking into bringing a boat out here so lookin at adding more to the low end torque and such. Any suggestions on legit upgrades, i dont want to break the bank and want to keep it reliable. Thanks for the help.

 

[mjonesjr]

If you want any performance upgrades, you are going to have to spend money.

Here is what I recommend:
- SCT XCalibrator 2 tuned by www.rougeperformance.com
- Underdrive pullies from www.stuffforyourranger.com
- Cold air intake
- headers
- cat back exhaust
- new gearing

 

[Bird]

The XCAL with a mail order tune will usually give a little bump in power - mostly accomplished by adding timing and changing transmission settings - at altitude, this may not help due to less air available - possibly could lead to detonation / pinging due to lean conditions. A good custom dyno tune at the altitude you operate at will always be better as the tuner, if he knows his stuff can set up the fuel / spark tables better for the existant conditions.

The pullies do decrease load on the engine, but at those higher altitudes, reduced operation of the water pump and fan may cause overheating issues - just something to keep in mind.

Cold air intake is basically a waste of money - most people see the same gains by just taking out the air box inlet restrictor - searching the various forums will explain.

The SOHC already has very good flowing exhaust ports and the factory exhaust manifolds flow quite well - most people report no noticable gains and a few have reported slight losses.

You might see a slight bump from the exhaust upgrade - definitely will hear it more.

Gearing is absolutely the best way to bump up your bottom end capabilities - especially if you're towing a boat.

Going from basically sea level, to 7000 ft is always going to reduce your performance - the air just isn't as dense and unless you go to some form of forced induction (turbo, supercharger), you will not have the power you had at sea level - it's all about movement of air through the engine. Sadly, there's no 'cheap' way to get this done and tricks that sometimes work on the 4.0 OHV usually don't apply to the SOHC.

Bird

 

[rickcdewitt]

there is a company or two who sell a supercharger for the sohc aren't there?

 

[mjonesjr]

www.explorerexpress.com

 

[badbronc92]

does anybody know what gears are in the FX4 (not Level 2)? 4.10? what would you reccommend i move up to riding on 32's.

 

[mjonesjr]

they are usually either 3.73 or 4.10 is stock. With 32's, either gear will be fine for 32's.

 

[MAKG]

I'd suggest 4.10 or even 4.56 given the altitude. 7000 feet really is quite significant; there is about 30% less air there in a given volume, compared to sea level.

Getting 30% more power out of any engine is very expensive. You would do much better to swap in an engine that already produces 30% more torque (presumably a later 5.0L, for instance). Getting 30% more torque at the low end isn't very hard with gearing -- but it's 3 steps, not 1.

Don't be afraid to blast at highway speed in 3rd if that's what it needs. It can handle it.

 

[badbronc92]

how much of a difference do 4.56 have over 4.10? What about gas mileage, not a big concern but just wondering if its worth the step up.

 

[Stenz]

I live in Colorado and you guys are exagerating it being so bad out here. My truck still runs great and has plenty of power.

Those who stated that mods in altitude could cause problems I think are mistaken. I know plenty of people out here that run, CAI, tuners/programmes, etc... and have perfect working trucks.

 

[badbronc92]

Hey Stenz just checkin out your truck description, can you post a picture of it cuz it sounds like the direction i was interested in taking mine. Did you get any benefit out of the K&N FIPK?