HomemadeTurbo - DIY Turbo Forum - Turbo 258/4.0 SX/4

I tried to post this a few days ago and it must have gotten lost or something. This is my second attempt. I will add pics shortly.

Howdy all,

I just finished a turbo setup on my '83 Eagle SX/4. The engine has been in the car for some time running a Moates modified '7747 ECM and was controlling a GM TBI. It is now Microsquirt.

The engine is basically as follows:

258 block 1/2" head bolt version +.060"
Comp 256 cam
4.0L head

That's basically the core of it. Other than the cam, head and bore it's pretty much stock. The new setup with the turbo goes like this:

Same block, head and cam
CAT C7 Turbo from a School Bus
1998 intake with stock Throttle Body and Injectors
Billet Aluminum Fuel Rail off Ebay (very nice unit, allowed for a return system, reasonable price) $110
Stainless Steel Header for a 99+ 4.0L the split style Ebay $85
Microsquirt w/8ft harness $400
Gm 3bar MAP, CLT and IAT sensors $60
36ft of random exhaust bends from Summit $200
5psi wastegate actuator Ebay $25
3" IC Piping Kit Ebay $100
3" Intercooler $85
T-4 Divided Flange Ebay $15
-6 AN Fuel Line Kit Amazon $35
Header Wrap for the Down Pipe Amazon $20
Thrush Muffler (Flowmaster Clone) Oriellys $40

I designed the hot side to capitalize on the twin scroll design of the CAT turbo. That is why I picked the header I did. I then ran 2 2in pipes from the left side of the engine and routed them to the old location of the A/C compressor. I deleted the A/C condenser to make room for the intercooler. I had to relocate the alt to right above the power steering pump. The battery was relocated to inside the right fender. At first I was going to just run the down pipe and call it good. It was however way to loud for me so I used random 3" exhaust pieces from the local salvage yard to run full exhaust.

I installed and wired the Microsquirt, reinstalled my AEM Wide Band and installed the FPR. I am still using the E2182 fuel pump that I was using with TBI setup. The injectors are stock grey top Jeep units. I deleted the Idle Air Control.

I had an issue with it hitting something that felt like spark was being cut around 3-4psi. I had my gaps at .027" so I really didn't think it was blow out. I figured I would replace the 30yr old TBI coil with an Accel unit. This cured the break up at 3-4psi and now blasts right though to 5-7psi. It has a 5psi actuator but it will creep to about 7psi. I have my Tuner Studio tables scaled to 150kpa so I have a bit of overhead for the boost creep.

The car has always ran strong but now it's an animal. The turbo lights off at right about 23-2,500rpm and lasts until were I push it to which is usually about 4,000rpm. The car has 3.55's in it so 1st gear is always a blur. The turbo does nothing in 1st due to the fact the engine sees virtually no load. 2nd comes on hard but is again a very short gear. 3rd is the money gear and 4th is also very strong. I live at 4600ft and right at the foot of the Big Horns in Wyoming. I can now take HYWY 16 all the way to the top in 5th.