Jeep Cherokee mods for +hp?

Dyer_Maker

I bought a Jeep Cherokee a few weeks ago. It has the 4.0 v6. What can I do to it to get more horsepower?

FW357

Buy a Horse.

I may not always be right, but I am never wrong. Magnum Force

Big Sky Redneck

Take it to your nearest Dodge dealer and get a full size Ram with a cummins Turbo diesel[:D]

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Politicians are like diapers, every so often you need to change them, for obvious reasons.

RustyBones

Copy n pasted from NAGCA.com, user ID Dino Savva:

4.0 I6 (Factory ratings 180-195hp@4600-4750rpm/220-235lbft@2400-3950rpm)

1. K&N cone intake: 5hp
2. Bored 62mm TB: 3hp
3. Bored 62mm TB spacer: 2hp/3lbft
4. Intake manifold heatshield: ?
5. HP plugs: 0-2hp
6. Splitfire plug wires: 3hp/6lbft
7. Dynomax Super Turbo cat-back exhaust: 7hp/9lbft
8. High-flow cat: 2hp
9. Tri-Y header/S-pipe: 10hp
10. JET Stage 2 PCM: 4hp
11. Speedtweaks IAT adjuster: ?
12. Electric fan conversion: 3hp/3lbft

With all the external bolt-ons listed above, output should be about 225-230hp. Beyond that, internal engine mods or forced induction are needed:

13. Ported stock cyl. head: 14hp/4lbft
14. Accurate Power big valve head: 16hp/7lbft
15. Crane #753901 camshaft: 10hp/15lbft
16. Raise CR from 8.8 to 9.5:1: 8hp
17. Accurate Power 4.6L stroker engine: 75hp/105lbft over stock
18. Accurate Power supercharger: 85hp/90lbft over stock
19. Nitrous Express kit: 50-75hp/90-135lbft over stock

TOOLS1

Small block chevy[:D][:D][:D]
TOOLS

General TOOLS RRG

Don't go blaming the beer. Hank Hill

So much Ice, So much Beer. So little time. Shooter4

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When I was a child, I thought as a child. But now that I am grown, I just wish I could act like a child and get away with it.

RustyBones

My grand has the 4.0 6cyl (its inline, not V) and it is pretty underpowered for the big grand cherokee. Im looking to do some mods myself, just havent gotten around to it. Ill probably start with the FIPK because thats the easiest, you just replace your stock air box with a tube and a cone filter.

ruger270man

A good free mod, is to remove the airbox, and if you look at the tubing to the airbox, there is a small hourglass shaped plastic piece in there, take it out, then put the airbox back on. That thing is a pointless piece of plastic that restricts airflow, more air = more fuel = more power.

Good free mod, did it to ours.

and for lots of jeep info, go to the forums at ...

www.jeepsunlimited.com

________________
Heston for prez.

Lowrider

Here's what I did to my '97 Cherokee Sport with the 4.0 IN-LINE six cylinder. Open the hood, Dyer_Maker, does that look like a V-engine to you?

K&N FIPK intake kit. Replaces the stock, very restrictive, air box with a snorkle tube and large K&N conical air filter.

MSD 6AL ignition module, MSD coil and MSD plug wires. Hot mutiple spark for increased power and maximum fuel efficiency.

JET Stage II engine control module & 180 degree thermostat. Recalibrates your fuel injection, and other computer-controlled engine functions for higher engine output. Even recalibrates your electronically-controlled automatic transmission. Thermostat runs cooler than factory 195 degree model. The jeeps run hot under the hood. Better to run a lower temp. 'stat.


Borla high-performance exhaust system. I also tossed the catalytic converter and replaced it with a straight piece of pipe.

Electric high-output fan to replace the belt-driven factory unit.

I originally installed a Helix throttle body spacer and it really improved the throttle response on my Jeep, but when I added the K&N intake I didn't have enough hood clearance and had to take the Helix unit off.

My Jeep six runs like a raped ape, I figure somewhere around 220 HP. If I keep my foot out of it it actually gets better gas mileage than it did when stock. A guy I work with has a V-8 Ford Explorer and my six-cylinder Jeep will eat him alive.

Lord Lowrider the Loquacious.

Member:Secret Select Society of Suave Stylish Smoking Jackets

She was only a fisherman's daughter,
But when she saw my rod she reeled.

Dyer_Maker

Thanks Lowrider,Ruger270man and rustybones. It is a inline 6. I'll start with ruger270mans mod then move on to the k&n fipk kit. Those are more than likely the cheapest. Then I'll move on to the exhaust later.

Swamp Thing

The 258 inline six is a great motor. LOWRIDER, I also ran a guy at work whom has a ford explorer with a 302-V8 and I beat him by a good respectable distance only, my cherokee 258 was stock. I like your idea on the STAGE II ENGINE CONTROL MODULE. RUGER, did you notice a differance when you took out that plastic object in the air tube? I'm going to take a look at mine and see how big that piece is, maybe I'll just take it out. My cherokee is a 4x4, I use it for off-road mode. I left my engine alone except for a header, flowmaster muffler and added a safari snorkel to it. I also have twelve inches of lift. I have never had a problem with lack of horse power. DYER, try changing your gears in the rear end, that always helps out.

COCKED,LOCKED,READY TO ROCK!!

Lowrider

Swampie: What year is your Cherokee? The newer 4.0 Liter engines are 240 cu.in., but I think it's the same basic design as the older 258 cu.in. engines.

Lord Lowrider the Loquacious.

Member:Secret Select Society of Suave Stylish Smoking Jackets

She was only a fisherman's daughter,
But when she saw my rod she reeled.

Swamp Thing

LOWRIDER, I have a 95 sport.

COCKED,LOCKED,READY TO ROCK!!

Brth729

ruger270man put up a good link. Here's another one with lots of info and technical stuff for all the models Jeep.

http://www.jeepnorthwest.com/



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