Turbocharged 4.0's
CF Veteran
Joined: Sep 2010
Posts: 21,168
Likes: 5
From: Milwaukee, WI
Year: 1987
Engine: Check
Yes, they are. At least you got the joke.
The "DSMs" were made in Normal, IL. There are also Ford Thunderbird turbo coupes. Mazda miatas were turbo at one point I thought. What's wrong with something not domestic? Most 'domestic' cars are from Mexico anyway.
If you have experience tuning a SAFC and EGT can be enough, a SAFC and wideband is easy. Use a pocket logger and laptop to monitor timing...but wait....I don't think the 4.0 can pull timing...
Build a hybrid turbo with an electric boost controller and external wastegate. You'll have boost anytime you want it. The 4.0 is big enough to spool a turbo pretty quick.
Actually quite the opposite. The colder the air the denser the charge. You just have to compensate with more fuel. And, depending on how cold, many crappy tunes can't compensate for the change.
A white 93 Eclipse GSX with a black top and black rims. There are a couple FB pics out there...
I hate hearing this. They are very reliable. Most people just hack them together with half assed mods they think are cool. Example venting the BOV to the atmosphere without converting to blow through. Then, when their rigged car doesn't run right they blame the car instead of their lack of knowledge. I see way too many of these cars on craigslist with missing vacuum lines and hoses plugged by screw drivers or golf *****. Then there are the guys that make a MBC out of hardware store pressure fittings and boost their 14b to 60psi and blow the head clear off the block when the stock fuel pump melts.
And that's enough of a rant from me about how the DSM got its poor reputation.
Yes, megasquirt would be good, and much better. But the price is a putoff for most.
Actually not so much, they will get you by but not the best options out there by far. ive boosted many cars and work for a high performance shop for some time. if you are on a budget that the way to go but if you want it to be reliable and actually get some power out of it then you will need something more reliable.
i like em both but for a jeep that gets used in the trailes and on some rocks id rather have a sc due to the immediate power rather than the boost lag. but for mud bogging the lag wouldnt be a huge deal cause your revving the **** out of it lol. but the smaller the turbo the lower the rpms it will kick in. the bigger the turbo the longer the lag. it would be awesome to get a stroked 4L with a super charger and a turbo lol.
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!
And that's enough of a rant from me about how the DSM got its poor reputation.
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?
Former Sponsor
Joined: Oct 2011
Posts: 102
Likes: 0
From: West Chester, PA
Model: Cherokee
I ran megasquirt in my old '86 VW GTI... it's an incredible system but takes hours upon hours upon hours of reading alone. Then you have to learn the tuning system, which involves more reading and a lot trial and error. Once you have a base line set and everything is running, it becomes easier and easier. If you have the time, definitely get megasquirt!!!
-Joe
Thread Starter
Seasoned Member
Joined: Mar 2011
Posts: 282
Likes: 1
From: Antioch IL
Year: 1993
Model: Cherokee
Engine: 4.0
http://www.jeepforum.com/forum/f12/f...-picts-661277/
^ this guy has the same turbo as me on the 4.0, only running a 12:1 FMU and a booster pump? another option? the turque curve on his is great for 6psi
^ this guy has the same turbo as me on the 4.0, only running a 12:1 FMU and a booster pump? another option? the turque curve on his is great for 6psi
Thread Starter
Seasoned Member
Joined: Mar 2011
Posts: 282
Likes: 1
From: Antioch IL
Year: 1993
Model: Cherokee
Engine: 4.0
installed boost guage and new oil feed line. turns out at almost 4k rpms im only running like 2psi? not spoooling neought? i checked for boost leaks? and wastegate isnt opening anymore, maybe an exhaust leak
CF Veteran
Joined: Feb 2011
Posts: 1,115
Likes: 0
From: Goose Creek, SC
Year: 1996
Model: Cherokee
Engine: 4.0 HO
I found this thread on NAXJA and figured it might help out here as well.
http://naxja.org/forum/showthread.php?t=1031285
http://naxja.org/forum/showthread.php?t=1031285
Thread Starter
Seasoned Member
Joined: Mar 2011
Posts: 282
Likes: 1
From: Antioch IL
Year: 1993
Model: Cherokee
Engine: 4.0
WOW that turbo build is nuts!
http://www.pirate4x4.com/forum/showt...=713450&page=2
heres another turbo xj build^
http://www.pirate4x4.com/forum/showt...=713450&page=2
heres another turbo xj build^
