This is an interesting topic and I wish there was more information about what a proper setup would be for the XJ.

My only experience with turbos is the car I drive everyday, an Audi A4 1.8T. I'm quite happy with it's performance and can imagine that a turbo on the I6 could only be a good thing. As for an intercooler, there is a small amount of room below the radiator and if you run an electric fan from a Ford Taurus it would cover both (intercooler and radiator). A remote turbo located close to the cat would be the best place and a proper skid plate would insure it not get damaged from rocks. It almost sound easy aside from the fuel management.

Come on, someone bite the bullet and do this. If people can squeez 250 to 300hp from a little 1.8L Audi motor then it should be possible to get that from the I6.

 

The point I was trying to make is that with a remote style setup, depending on boost level, turbo choice, etc. you wouldn't need much of an intercooler, if you needed one at all. A simple intake temp gauge would tell you the answer. I knew a guy who turbo'd a 3.0 ranger without an intercooler and it was making plenty of power.

This is something that is going to happen for me. Its not gonna happen soon, but it will happen. Plans have already been set in motion to do a low compression stroker, and after that a turbo is almost mandatory.

 

My experience with custom turbos is limited too. I had a wrx and now have a daily driven 08 legacy spec.b 2.5 turbo and my autox toy a 90 miata that i put a turbo on. On a miata it was easy, there is a ton of space in the engine bay. I have a small gt2554, 600cc injectors, and megasquirt ecu to make it tunable. Stock hp for a 1.6 miata is about 90hp. At 13psi on e85 i made 200hp to the wheels on a dynojet.

So i am sure a 4.0 with a remote can make over 250 to the wheels.

 

Remote turbos aren't as good as an engine bay turbo. Tubos spool by exhaust gasses expanding in the turbo, not just exhaust blowing through them. My the time the exhaust gets to a remote turbo the exhaust has cooled down to the point that it doesnt have the punch that it has if it was close. If you want more power wheeling, a turbo isnt what you want. Its a 2000+ RPM power adder, not a 1500 RPM torque adder. Engines gotta spin to spool the turbo.

And its not just as easy as adding a turbo, I dont know what type of pistons are in a 4.0, but unless they are Hypers, they will shadder the first time you get detonation. You need Hypers at the minimum, or better forged. You need to increase fuel pressure too, and a renix wont do it, or a HO computer. F.A.S.T. is the way to go or something similar. You cant push 10 PSI into the intake and expect it the computer to know. You will need some 40lb injectors, some good head gaskets, and exhaust work. If you take the time to route a turbo, put an intercooler in. Its worth the time.

I have a turbo on a buick 3.8 Vi6 n my cutlass at 8 PSI nonintercooled. 91 Octane and a MSD BTM. Im never on the turbo as I have no knock sensor. I dont feel like scattering my $1200 rebuild, previous owner already did.

 

put a supercharger on the thing and be done with it, less headaches and less routing of anything.

http://4wheeloffroad.automotive.com/...kit/index.html


http://www.kennebell.net/supercharge...wrangler40.htm

 

http://www.jpmagazine.com/techarticl...t_2/index.html

cheak this out

i beleave this is ower inline 6 guysits a newer jeep eng tho but still a inline 6! lol lemme get that for my jeep

 

Ive seen a few turboed 4.0, mostly in wranglers. They are sweet but mostly used for desert racing. There is no bolt in system, you have to build it from scratch and make it work. There is a company that sells an exhaust manifold somewhere that you bolt a turbo to right near the firewall, i just dont fell like looking for it.

oh and the 4.0L can only hold like 6-8psi unless you drop alot of $$

 

No remote turbo but have a friend that has it. I am amazed when he showed it to me.

 

Not for XJs, no, but for Wrangler 4.0s.

Why can it only hold 6-8 psi? A set of ARP headstuds and a MLS headgasket will go a long way, and won't cost more than a couple hundred bucks.

If you are turboing an XJ, though, you probably aren't that worried about money. Just sayin.

Your right, they aren't as "good", but you can still make it work. Use a hybrid turbo, aka a frankenstein, and you'll have boost lower than 1500rpm if you want.

Since its an I6, you only need one headgasket, so that'll cut cost down.

What do you use to monitor your Cutlass?

 

i can only imagine how you garage looks, must be awesome

 

I am by no means a turbo expert, but the thing I think people are overlooking is the plumbing that would go with a remote turbo. It seems to me that a big skid plate over the turbo would work, but what about having to protect the pipes going into and out of the turbo? I've also seen that the older style (gen 1) superchargers that ripp makes for the jk 3.8 has a water/methane injection system. Don't know if that could work for a turbo, but it seems like that could be a good substitute for an inner-cooler as far as cooling the air going into the engine, especially at crawing speeds.

 

^ why do people keep omitting my comment about air-water coolers. An FI system at "crawl" speed can still be cooled; just not by an air-to-air heat exchanger. But I agree with ya, I don't think a remote turbo is such a great idea for a vehicle that you plan to bottom out often.


Frankenstein turbo.... Just b/c the A/R's aren't closely sized doesn't make it some freak turbo. It's like when the Honda guys say they want a T3/4 hybrid b/c they've read it a couple times.

Basically there is almost an infinite availably of turbine housings, CHRA's and impeller trims to assemble what is desired for the particular application. What people miss is the mathematical formula's behind it. Just saying, "turbo's are laggy" is completely incorrect and ignorant.

 

Not everyone.




I never said "freak" turbo. I don't get what your point is about me calling it a "Frankenstein" turbo. Its not wrong, incorrect, or anything of the sort.

Do you know the "story" of "Frankenstein?" Some scientist "built" a person out of parts from several people.

Hense the term "Frankenstein" turbo. Not "freak" turbo.

You take the parts from several different turbos to make one that suits your needs.

Since no turbos are really "built" or designed for the Jeep XJ 4.0 and its engine bay/space for mounting, chances are one will have to put together something, as you suggested.

And as I've suggested many times.

I think you just misread my post or missed my point completely.

 

i have seen a few done, and did alot of research cuz i have been wanting to do this if you make your own i would use a eclipse or talon turbo they spool up quicker and have a build in wastegate, i kind of gave up on my plan cuz i just redid the exhaust and put 2.5in pipes on and everything is really tight.

 

plus i found this supercharger http://i28.tinypic.com/2vm5yxz.jpg