: converting non-DI to DI

03-16-12, 11:04 AM
I have access to an intake, fuel rails, plenum, and injectors for a direct injection cts at about $100 bucks as this guy is parting it out and needs it gone asap. mine is currently non-DI. I was wondering if anyone knew what it is involved with doing the swap. i know its a far shot but being that i can get the parts so cheap i wanted to check. the stealership said they could do the ecu for me, just wondering what the difference is in the parts category. thanks guys for any feedback.

00 ss
03-16-12, 11:12 AM
I think it would be far earier to just get the whole engine from the guy and swap it in. At a minimum you'll need the heads and the injectors as well. If you can get the engine wiring harness for the DI as well it should make hooking the injectors and other sensors up a bit simpler. I really don't know if the DI heads are direct bolt on for the non DI block or not. Are the pistons the same in both engines?

You're also going to need the DI fuel pump and all the small pieces in the fuel delivery system since it operates at MUCH higher pressure than the non DI version.

This sounds lie a MAJOR project to me. Good luck and let us know how it goes.

03-16-12, 11:16 AM
way cool thank you, thats what i was looking for. I'll have to see what he wants for the engine and other parts to see if its worth it. i didnt know the heads were different and the fuel pump.

00 ss
03-16-12, 11:24 AM
The heads have to be different. DI means direct injection. The injectors put the fuel directly into the combustion chamber. In non DI engines, the injectors put the fuel in the intake manifold runner near the head intake port. That's also why the fuel pressure has to be so much higher. The injector has to overcome the cylinder pressure under full compression and heave enough pressure left over to atomize the fuel.

03-16-12, 01:07 PM
This will be one major PITA.

00 ss
03-16-12, 01:17 PM
Agreed. In fact, it would probably be cheaper to sell his current car and buy a used DI car with similar mileage to one he has. It would definately be alot faster and easier.

03-20-12, 12:29 PM
I addressed this one a while back. Its entirely possible but would require a bit of persistence to get it all done right.
See my answer here:

I am a GM employee. My opinions do not represent those of the company.