Topic: Turbo Charged TJ

[rockford]

I am looking to turbo my 2.5 tj with a T3/T4 turbo.  I want between 6-7 psi of boost, and i want it to be a fairly simple setup.  I know you guys with the YJ's are using 19# injectors and a 12:1 FMU, i am wondering what you guys would suggest for a TJ.  I know the stock TJ injectors flow more then YJ ones, so which ones would you suggest, and which FMU should i get.  I am looking to get this underway by the end of the month.

Mike

[Jeffy]

This will give you an idea of what was used.

http://4bangerjp.com/forums/index.php?topic=3479.0

I'd say 24#'s would be a good place to start.

[rockford]

Would that and a FMU be good enough for the fuel side of things?  would i need an adjustable map sensor?

[Jeffy]

Would that and a FMU be good enough for the fuel side of things?  would i need an adjustable map sensor?

I think you'd still want Fuel Management.

[rockford]

what do you mean by that?  This is my list sofar

T3/T4 turbo
Intercooler
24# injectors
8:1 FMU
All of the lines and piping

Anything else needed?

Also, would turboing enable me to not regear or atleast change the proper gear ratio if i do decide to do it?  Im only running 33" AT's

[st.chevrolet]

I’m running 25lb injectors with a 12:1 FMU, and a stock MAP sensor on my 2.5L YJ with 7 psi boost and its worked great, I have been driving it for about 3 weeks now.
I could be mistaken but the one problem I see with a FMU on the TJ 2.5L is, there is no return line on the TJ engines. I’m just going by the TJ's I have see, like I said I could be mistaken.

[Rob the plumber]

I also heard that TJ's have no return line. That makes adding extra fuel more difficult for sure. There is virtually no aftermarket support for this kind of stuff. Megasquirt is always an option though.

[rockford]

if i just threw in larger injectors, would that work?  Im sort of new to this.  what about an adjustable maf sensor?  how does megasquirt work?

[Jeffy]

I also heard that TJ's have no return line. That makes adding extra fuel more difficult for sure. There is virtually no aftermarket support for this kind of stuff. Megasquirt is always an option though.

Nope, I looked that one up earlier.

[rockford]

what options do i have here boys?

[st.chevrolet]

I have heard the thought thrown around about using the older injection system off the YJ, so you could use a FMU or other fuel management system.

[rockford]

I was reading around, and Air Sierra on this board didnt even use any fuel management when he turbo'd his 2.4l.  apparantly his computer adapted to the 6lbs of boost he put through it.  which is all i am going to be doing.  Im assuming that he used stock injectors aswell.  I think a T25 turbo with 5-6lbs of boost might function alright with OBD II adjusting the fuel curve.

[Rob the plumber]

Mass air systems are pretty adaptable, but to throw a turbo on a speed density controlled engine with no extra fuel would be very bad. Megasquirt is a stand alone engine control computer. You don't even use the Jeep ECM with it. It is definitely not for noobs though.
Just throwing in larger injectors would make it run way too rich. It probably would not even idle very long.

 

[st.chevrolet]

You can always bypass the stock fuel pressure regulator in the fuel tank, run a return line to the front and use a YJ fuel rail. It will take a little work adding fittings at the tank end, but it can be done. When I put the 97 Vortec 5.7 in my 80 Chev 4x4 I also had to add an additional line from the 97s vapor cannister to the tank.

[rockford]

If i were to do that, what kind of injectors would i use?  24# and an 8:1 FMU?  seems like an easy enough setup. also where could i find a yj fuel rail?  and how would i bypass the pressure regulator, its sort of built into the fuel pump, and the fuel filter.  any special tips or guides?