Turbo?

[Jason]

I have built a few turbo set-ups before. My question is this. How will a 4.0 handle a turbo? I now it would require a boost controller to keep the pressure low for everyday driving. However, how much can the factory sensors compensate for? How about injectors? What type of boost can a 4.0 take without being overtaxed and requiring MAJOR upgrades?

 

[Jason]

All the knowledge here and no one has any answers to this one?

 

[Twizzler09]

I honestly don't know.

If I had to guess I'd say your looking at most 4# of boost before you have to really start upgrading things. I think I saw someone here on the forums say that somewhere....

 

[Sevensecondsuv]

I looked into it a while back for my explorer. Now I've decided to swap a 2.3T in my ranger instead. Turboing a 4.0 is pretty much uncharted territory.

The 4.0 really doesn't have many weaknesses, so theoretically it should handle low boost just fine. The answers I found were that on a good quality rebuild it should handle 5 PSI just fine. I was told all I needed to do was installing a rising-rate fuel pressure regulator to up the fuel as the boost went up. This will get the AFR close enough that the computer can figure out the rest.

Going anymore than 5 PSI is just not cost effective. Forged pistons are mega $$$ and hard to find. I also couldn't find any "turbo" rated head gaskets either. Probably the biggest reason no one ever turbo's them is because the 4.0 ranger engine bay has little room left for the turbo set up, let alone an intercooler.

You can have power much cheaper from a 2.3T.

 

[Jason]

The truck is an 04 so a complete engine swap isn't feasible right now. The turbo's are quite small now so fitting it would be tight but not terrible as the is plenty of room under by the firewall. Intercooler in theory would be mounted in front of the rear wheels and fed by a deflector to direct some airflow. That would of course require a ton of hard plumbing though. I guess the pocket may have to just save for the supercharger. 5 psi is not worth the trouble of a turbo. If the engine could take 8-10 it would be green lighted.

 

[Sevensecondsuv]

I'm by no means an expert on the subject, but I've heard repeatedly that the 4.0's cast pistons just won't hold up past 5 PSI.