Turbocharged 4.0's
Seasoned Member
Joined: Oct 2011
Posts: 262
Likes: 0
From: Syracuse NY
Year: 1994
Model: Cherokee
Engine: 4.slow
CF Veteran
Joined: Feb 2011
Posts: 1,115
Likes: 0
From: Goose Creek, SC
Year: 1996
Model: Cherokee
Engine: 4.0 HO
::Regional Moderator::
Joined: Aug 2011
Posts: 4,742
Likes: 10
From: Jacksonville, NC
Year: 1993
Model: Cherokee
Engine: I6 4.0L HO
I love my xj but id wouldn't do that to her....not practical....but **** it I wana do it
..stroke to 5.0!!!!!!!!! Sc and turbo it...
..stroke to 5.0!!!!!!!!! Sc and turbo it...
Thread Starter
Seasoned Member
Joined: Mar 2011
Posts: 282
Likes: 1
From: Antioch IL
Year: 1993
Model: Cherokee
Engine: 4.0
WOW this thread exploded.
i am going to be installing bigger injectors and a 2 bar map sensor soon. just got my new oil feed line back form the hydraulic shop, so gonna throw it in tomorrow, also buying a boost gauge. i dont hear any tinging or knocking or anything. sounds totally normal under boost. surprisingly its spooling at about 3000 rpms roughly right now, little higher then i wanted. might have to go with a bigger downpipe for more flow. will post a video tomorrow
keep comin with the suggestions!
@ Gee oh Dee- you have a tsi? ive really been looking into one but cant afford the $2500 price tag plus the cost of building one up!
i am going to be installing bigger injectors and a 2 bar map sensor soon. just got my new oil feed line back form the hydraulic shop, so gonna throw it in tomorrow, also buying a boost gauge. i dont hear any tinging or knocking or anything. sounds totally normal under boost. surprisingly its spooling at about 3000 rpms roughly right now, little higher then i wanted. might have to go with a bigger downpipe for more flow. will post a video tomorrow
keep comin with the suggestions!@ Gee oh Dee- you have a tsi? ive really been looking into one but cant afford the $2500 price tag plus the cost of building one up!
Senior Member
Joined: Jun 2010
Posts: 632
Likes: 1
From: Ft. Myers, Fl.
Year: 1997, 1999
Model: Cherokee
Engine: 4.0
So when you put in a two bar map and bigger injectors what is that going to do for you? I still don't see how you plan to tune this thing. If you continue on this path you're going to blow you engine.
If you're on a budget I strongly suggest you look into the afc hack. That and a wideband should get you a safe tune.
If you're on a budget I strongly suggest you look into the afc hack. That and a wideband should get you a safe tune.
Senior Member
Joined: Jun 2010
Posts: 632
Likes: 1
From: Ft. Myers, Fl.
Year: 1997, 1999
Model: Cherokee
Engine: 4.0
The ecu will still think it had the stock map sensor in it.my net is that it won't even run with the 2 bar installed. I strongly suggest you stop driving the truck until you get it tuned properly. Get a intercooler to, it will help make a lot more power and help fight detonation.
Thread Starter
Seasoned Member
Joined: Mar 2011
Posts: 282
Likes: 1
From: Antioch IL
Year: 1993
Model: Cherokee
Engine: 4.0
piggyback is out of budget. did some research and most people say to use the afc hack with bigger injectors. probably what im going to do. maybe a wideband in the future. so far i gathered you need 10 watt 10 ohm resistors, what else?
Senior Member
Joined: Jun 2010
Posts: 632
Likes: 1
From: Ft. Myers, Fl.
Year: 1997, 1999
Model: Cherokee
Engine: 4.0
You need to figure out what injectors you a are going to use before you know if you'll need resistors or not.
CF Veteran


Joined: Jan 2010
Posts: 1,456
Likes: 74
From: North Riding of Yorkshire, UK
Year: 1997
Model: Cherokee
Engine: 4.0
The cheapest way to do it "properly" is megasquirt and a wideband o2 sensor. It'll take some setting up but there must be someone out there who has done it to a 4.0 before.... you could try talking to people on e30tech - they like doing this sort of thing to e30 bmws with the 2.5l straight six. They've got some insane power out of those things, but the head does flow nicely from stock...
What is the compression ratio of the stock 4.0?
What is the compression ratio of the stock 4.0?


